Tiny black flies on plants

Sharing is caring!

11342shares

  • Share
  • Tweet
  • Pin
  • Reddit
  • Yummly

The kneejerk reaction to a spider might be to grab a can of Raid, but there are many less toxic ways to get rid of spiders. Instead, try one of these 8 Natural Spider Repellents listed below, such as the spider spray.

We also include tips to get rid of spiders in your home by making it a less welcoming habitat, and reasons to like spiders.

Finally, we wrap up with a quick discussion of standard repellents and more pest control tips.

Please note, eradication of all spiders from a home is difficult and unnecessary. It’s better to catch them and put them outside, if possible. (Truly dangerous spiders like black widows or the brown recluse are the exception.)

Not every option will work with every spider. It may take extra encouragement to get the spiders to relocate.

Contents

Natural Spider Repellent #1 – Herbs and Essential Oils

Herbs have been used for centuries as a pest repellent and are still just as effective today. Essential oils in these plants act as nature’s bug repellent and insects tend to avoid them.

You can make up small sachets of the dried herbs and tuck them around your home, or mix up a spider repellent spray. (You can also purchase herbal pest repellent sachets online here.)

Spider Repelling Herbs and Essential Oils include:

  • Eucalyptus
  • Citronella
  • Lavender
  • Peppermint
  • Tea Tree
  • Cinnamon
  • Citrus
  • Cedar

One drop of any of these essential oils will kill a spider. Please note: Do not get undiluted essential oils on skin, clothes or wood. Keep essential oils out of reach of children. See “Herbs or Essential Oils – Which is better?” for a discussion of herb and essential oil use.

Do spiders really not like peppermint oil?

I think everyone on the internet has seen images that say “spiders hate peppermint” or “use peppermint oil for spiders”.

It’s true that spiders generally don’t like peppermint oil, but you can also use any of the other oils listed above. It’s your choice.

Use one or more of the essential oils above to make your own peppermint spider repellent spray or essential oil spider repellent spray. I demonstrate how to mix up a batch in the video below. (If the video doesn’t display, please make sure your ad blocker is disabled.)

You can also .

DIY Spider Repellent Spray (Peppermint Spray for Spiders)

Ingredients

  • 5-10 Drops of any of the above essential oils, such as peppermint essential oil, or a combination of the oils
  • ¼ tsp Dish Soap
  • 12 oz of Distilled Water

Directions

Mix all the ingredients in a glass spray bottle and spray effected areas weekly until you no longer notice spider activity.

Natural Spider Repellent #2 – Diatomaceous Earth (DE)

Sprinkle diatomaceous earth along the areas where you see bugs or spiders crawling, such as window sills. Make sure that the DE is distributed evenly, like a thin layer of dust.

Remember, DE won’t stop bugs in their tracks, it will slowly dehydrate and kill bugs after coating them. The idea is to get bugs to move through DE in order to get exposed. House spiders are prime targets for DE. They are in a dry environment and can be dehydrated by DE quickly.

If you live in a trailer or on a crawlspace, spread DE underneath your home. You can also add drops of peppermint essential oil to cotton balls and place them under your house.

Natural Spider Repellent #3 – Add Plants that Repel Spiders

Add spider-repelling plants around the perimeter of your home to deter spiders from taking up residency.

Spider repelling plants for your garden include:

  • lavender
  • lemon balm
  • lemon verbena
  • eucalyptus
  • lemon grass
  • mint

Cedar mulch also helps deter spiders. You can also shake cinnamon around the exterior of your house. Cinnamon works as an ant repellent, too! See also “Plants that Repel Mosquitoes“.

Natural Spider Repellent #4 – Nuts

Place chestnuts around the outside of your home, under furniture or on windowsills. Horse chestnuts (Aesculus hippocastanum) or walnuts can also be used.

From Can you conker terrifying giant spiders with humble horse chestnut under the sofa?:

…scientists are divided over whether the saponin compound found in conkers is an effective spider repellent. Some describe it as ‘an old wives’ tale’.

Spider expert Jack Fenwick said:

‘The jury is out on whether it works. My cousin, who is very scared of spiders, tried conkers in her home and said it worked very well.’

Some experts say saponin gives the seeds a bitter taste and a smell that could act as a natural repellent.

Natural Spider Repellent #5 – Sticky Traps

According to experts, glue traps are the single best way to get rid of your spider population and other insects. You can place them anywhere and they are non-toxic.

You can buy traps at most hardware stores, or you can get the family involved and make them yourselves.

For instructions on how to make your own sticky traps, go to Making Your Own Glue Traps. You can also buy sticky traps online.

Natural Spider Repellent #6 – Tobacco Spray for the Yard

To make a natural spray repellent to use in your garden and in your yard:

  • Boil 1 gallon (4 l) of water.
  • Add 1 package of pipe or chewing tobacco to the water and let the tobacco soak until the water cools to room temperature.
  • Strain this mixture into a clean container.
  • Put 1 cup of the tobacco juice and 1/2 cup of mint into a hose-end sprayer.

Attach the hose sprayer to your garden hose and spray problem areas of your yard. This mixture also repels mosquitoes and other pests.

Be selective in your spraying! This mix will also kill all the many beneficial insects in your garden, like lady bugs and beetles. Spiders are beneficial in the garden as well – eating lots of mosquitoes and plant pests.

Natural Spider Repellent #7 – Spider Repelling Air Freshener

Citronella repels more than just mosquitoes – it also repels spiders! Add a couple of drops of citronella essential oil to your candles or air filters.

Spiders hate the smell of citronella and will avoid areas with this oil. Using lemon dust cleaner helps too.

Natural Spider Repellent #8 – Saltwater

Salt is a natural type of spider poison, so it makes an effective pest control. Dissolve an ounce of salt (1/8 cup) in a gallon of warm water. Use the saline mixture to fill a spray bottle.

Spray the salty solution directly onto a spider to kill it. Salt water is also effective at killing spider nests. This works best with thinner skinned spiders and immature spiders.

5 Tips to Get Rid of Spiders in Your Home

While spiders have many admirable qualities, not everyone likes to have them as house guest. The best way to get rid of spiders in the house is to eliminate their food and the places they like to hang out.

#1 Leave the Lights Off

Lights attract mosquitoes and other flying insects, and spiders feed on these insects. Reduce a spider’s food source, and you reduce the number of spiders.

See Natural Mosquito Repellents That Work for more information on how to get rid of mosquitoes.

#2 Remove Their Home

Remove stacked flowerpots, wood piles, bricks, firewood, and other debris that may serve as homes to spiders. Store these items away from your home and at the farthest part of your property.

#3 Protect and Seal

Caulk or seal cracks or gaps around the foundation, doors, and ground level windows that spiders might enter through. This also makes it easier to keep your home warmer in winter and cooler in summer.

#4 Clean House

Do regular housecleaning, including vacuuming webs or spider sacks. Make sure you get around windows and baseboards.

See “DIY Natural Cleaners” for non-toxic cleaning recipes and Spring Cleaning – 6 Tips to a Clean and Organized Kitchen.

#5 Recycle and Declutter

Don’t let your recycling accumulate, otherwise you’ll be opening up a spider hotel with a neon vacancy sign. Remove newspaper stacks, cardboard, boxes or other clutter on a weekly basis.

Getting over a Fear of Spiders

According to statistics 30.5 % of the US population has a fear of spiders. This means that over 97 million people that have a fear of our eight-legged insect controlling friends. Many of these 97 million people are using some sort of toxic chemicals around their homes to get rid of spiders.

I’m not trying to make light of those with Arachnophobia – the fear is real and can be seriously debilitating. (Spiders are closely related to mites, ticks, and scorpions and are collectively known as arachnids. )

However, I hope to persuade you not to not use harsh or toxic chemicals, and opt for a more natural approach.

To learn more about overcoming your fear of spiders, read Overcoming the Fear of spiders in Two Minutes.

5 Reasons to Like Spiders

#1 Spiders Provide Insect Control

Spiders feast on mosquitoes and other bothersome insects. More spiders = less mosquitoes. Anything that eats mosquitoes is my ally.

#2 No Spiders = Less Food for Humans

“If spiders disappeared, we would face famine,” says Platnick, who studies arachnids at New York’s American Museum of Natural History.

Spiders eat bugs that eat our crops. They and other predators reduce or eliminate the need for chemical bug killers. Read more at The Case for Spider Conservation.

#3 Spiders are a Food Source for Many Other Species

Spiders serve as a tasty meal to several other species including other spiders, wasps, birds, reptiles, and amphibians. They’re an important part of the food chain.

#4 Spiders Produce Valuable Resources

Spider silk has a higher strength-to-density ratio than steel. Think bullet proof vest, airplane products, medical supplies and more.

If lose a spider species, we may lose a cure to a disease or an ingredient for a life-saving material.

#5 Spiders are Survivors

Spiders have been around for 300 million years, and anything that lives that long deserves respect.

Home Spider Control – Conventional Pesticides vs Natural Spider Killers

How dangerous are conventional pesticides? Insecticides have serious health and environmental risks.

At one time it was thought that pesticides only killed or injured spiders and insects. Now we know they can poison more than just the bugs.

From the McDaniel College Pesticides Risk page:

USA: Based on extrapolation of hospital surveys, an estimated 20,000 people receive emergency care annually for actual or suspected pesticide poisoning. Approximately 10% are admitted to the hospital.

Each year, 20-40 people die of acute pesticide poisoning in the United States. We don’t know how many affected workers in the United States never see a doctor.

“Neurotoxicity of pesticides: a brief review” notes:

“The effects of pesticides on the nervous system may be involved in their acute toxicity, as in case of most insecticides. They may contribute to chronic neurodegenerative disorders, most notably Parkinson’s disease.”

These natural spider repellents and deterrents for the home won’t kill every spider, but they won’t get you sick, either.

I’d love to read your spider control tips and spider stories. Please leave a comment below.

More Pest Control Tips

You may also find these other posts from our Green Home Series useful:

  • Spider Bites – 6 Natural Treatments + Tips to Avoid Getting Bit
  • How to Get Rid of Mice in Your Home and Garage
  • How to Get Rid of Ants Naturally
  • 9 Tips to Get Rid of Fruit Flies, Plus the Best Homemade Fruit Fly Trap
  • How to Get Rid of Fleas (Non-toxic, Pet Safe Options)

This post is by Amber Bradshaw of My Homestead Life.

Amber’s family moved from their tiny homestead in South Carolina to the Smoky Mountains in East Tennessee.

They cook without electricity, collect water from the creek and raise chickens, goats, pigs, turkeys, bees, and guineas.

They were featured on the TV show “Building Off The Grid: The Smokey Mountain Homestead”.

Originally posted in 2016, last updated in 2020.

How spiders can harm and help flowering plants

The harmful side of crab spiders

Crab spiders are predators that lie in wait for their prey on the flowers. It used to be assumed that these spiders harm the plant, because they catch pollinating insects or discourage them from visiting the flowers. The ecologists at UZH have now been able to reveal a surprising phenomenon: “Crab spiders find the plant by following the scent of its flowers. They do so using ?-ocimene, the floral volatile that also attracts bees,” says Schiestl.

Floral volatile serves as a cry for help

Indeed if crab spiders are sitting on the flowers, fewer bees will visit because they’re discouraged by the spiders. But the spiders don’t just eat pollinators. They also eliminate plant-eating insects and their larvae that feed on the flowers or fruit and damage the plant. This way the crab spiders benefit the plant, bearing out the principle that the enemy of my enemy is my friend. Apparently the benefit is so great that when attacked by florivores, the plants give off larger amounts of the floral volatile that attracts the spiders. This “cry for help” actually works: in response to it the spiders are increasingly likely to visit the flowers that are being attacked, where they find rich pickings.

Understanding interactions to protect ecosystems

The study shows that the effect of interacting organisms is highly dependent on the ecological context. But in complex ecosystems the consequences can’t always be predicted. This means that the disappearance of existing interacting partners or the appearance of new ones can have unforeseeable implications for individual members of an ecosystem. “For this reason it’s important to better understand the interactions between organisms and their consequences to be able to apply the insights in the protection of ecosystems or organic farming,” concludes Florian Schiestl.

Plants and pests go together like peanut butter and jelly. If you have the 1st, then the later will make an appearance at some time. I’m more familiar with and have seen these pests infesting houseplants more than plants in the landscape. What I’m talking about here is fungus gnats and root mealybugs (some call them soil mealybugs) and what you can do to control them.

This is part of a plant pest series which I did about 4 months ago and then dropped the ball on these 2. Oops – better late than never I say! In my professional gardening days, I encountered aphids and mealybugs, spider mites and whiteflies, and scale and thrips much more often. Unlike all of those which hatch on the plant itself, the fungus gnats and root mealybugs hatch in the soil. The control for them is very different.

Talking fungus gnats & root mealybugs:

Fungus Gnats:

I’m going to start with fungus gnats. The adults, after hatching in the soil, fly around and you can see them. They like moisture, humidity and rich matter like compost, decaying leaves and peat moss. Although they can be found outside around drains and areas with poor drainage, my limited experience with them is more around houseplants. In the home, they’re a noticeable annoyance.

Good to Know

I’m not going into the lifecycles of either fungus gnats or root mealybugs. All I’ll say on this subject is to catch them early on because they breed like crazy. If you wait, they’ll be much harder to control.

They’re teeny, tiny blackish, greyish flying insects. 1/4″ is the largest they get largest they get, but most are much smaller than that. The pictures of fungus gnats that you see are all magnified which is why I don’t have one taken by me. I’d need a super telephoto lens for that but you can see some pics here.

They oftentimes get confused with fruit flies but they’re 2 separate pests. Fruit flies hang out in the kitchen around rotting fruit and vegetables and are stronger fliers and slightly bigger than fungus gnats. Fungus gnats stick pretty close to the plant they’ve hatched out of.

Adult fungus gnats are short lived. They fly around for a few days and then die. What makes them super annoying is that if they get close to you, they like to fly up your nose and in your ears and mouth. Remember – they like moisture! They lay eggs near the surface of the soil, larvae appears which hatches into the flying adults and then the whole cycle starts over again.

The adult flies don’t do any damage to the plants. The larvae, if left untreated, can damage a young or small plant. They rarely do any damage to an established or large plant.

Symptoms damage has been done: The plant looks limp, weak growth and can loose foliage if the infestation is bad.

How to prevent fungus gnats: Ease up on the liquid love. Fungus gnats thrive when houseplants are over watered.

Control for Fungus Gnats:

In my short-lived career as an interior plant care technician, we dealt with a lot of fungus gnat infestations. Most of the plants had moss as topdressing, which keeps it from drying out even more. Here’s what we did:

Removed the moss & took it away in a garage bag in case any eggs or larvae had gotten into it.

Let the plant dry out as much as possible. Sticky yellow traps were placed in or next to the plants to trap the adults. You can use them in your home if they’re driving you crazy! If the clients were really complaining about the fungus gnats, we got right to the drench but I recommend the drying part 1st because the plant is probably already wet at this point.

Mix up a solution of 1 part pure hydrogen peroxide (with no additives) to 4-5 parts water. Mix well and water the plant, making sure to thoroughly drench all parts of the soil. The hydrogen peroxide will fizz; that’s what kills the larvae and the eggs.

Repeat in 2 weeks for a larger pot; in 7-10 days for a small pot.

Other things I’ve heard to be effective (but have never tried):

Mosquito dunks in granular form sprinkled on the surface of the soil & watered in.

A special type of BT (called Bti) used as a drench.

Neem oil used as a drench (this gets mixed reviews).

Nematodes. These are beneficial insects that when released into the soil, start to eat the larvae.

Root (or Soil) Mealybugs

Root mealybugs are much harder to detect because they’re in the soil and you don’t see them unless you take the plant out of the pot. Sometimes there might be a few lurking near the surface but they like to hang out down below feeding on the roots.

Root mealybugs resemble specks of white cotton or a white fungus. Look closer (you may have to get a magnifying glass) & you’ll see them moving slowly or if not, legs will be evident.

If the plant is going in the garden, you’ll notice them right away when you take it out of the pot. Return it to the nursery as soon as you can. They, as well as houseplants, can carry root mealybugs in from the grower or garden center.

Symptoms damage has been done:

Root mealybugs suck the sap out of a plant so you’ll notice stunted growth, less vigor, leaves turning yellow or brown. You know – all the typical stuff that’s common to a lot of other plant problems!

How to prevent root mealybugs:

Inspect your plants right away when you get them home by taking them out of the grow pots.

Control for Root Mealybugs:

The only experience I have with root mealybugs was in our greenhouse in Connecticut when I was growing up. We had a lot of plants as well as seedlings but the scented geraniums, zonal geraniums, pelargoniums, and streptocarpus all got it at 1 time or another. I’ve heard that succulents and african violets are prone to them too.

Here’s what my dad would do:

Knock off as much of the soil as possible.

Place it in a bag & put in the garbage. Don’t put it in the garden or compost.

Soak the roots, covering the top of them, in a pail or tub of hot water.

My dad always said, “not warm but not scalding”. I researched this a bit to see if anyone else had done this so I could get more exacting temps. You want the water to be in between 110 – 120 degrees F. Basically you want it hot enough to kill the critters and their eggs but not so hot that it harms the roots.

Leave the plant in the water for ten minutes.

The root mealybugs get killed almost instantly but you want to leave it in for good measure.

Repot the plant in fresh potting soil with a sprinkling of diatomaceous earth mixed in.

In case there’s any of them or their eggs left on, this will get it.

If you’re putting the plant back in the same pot, make sure to soak the pot in boiling hot water to get any root mealybugs off which might be hanging out on the sides or the bottom. Give the pot a good scouring too.

Other things I’ve heard off to be effective:

There are pesticides drenches out there but I don’t know much about them. You want to be careful not to use anything too strong because you don’t want to harm the roots.

Root mealybugs are treated differently than the mealybugs which hang out on the plant so don’t even bother trying horticultural oil, insecticidal soap, neem oil, etc.

Dealing with pests is no fun but it’s part of having plants.

Keep your plants as healthy as possible and they’ll be better able to survive any infestations. Do you have anything different that you’ve found to be effective for fungus gnats or root mealybugs? Please share!

Happy (pest free) gardening & thanks for stopping by,

Spider mites (Tetranychidae) are common pests of many outdoor crops including berries, ornamentals, vines, many fruit trees, hemp and cannabis. There are many subspecies of spider mites in the Tetranychus genus including the Pacific Spider Mite, Two-Spotted Spider Mite and Strawberry Spider Mite. Some species are more easily identified than others; however, it is generally unnecessary to do so as their biology, damage, and control measures are similar or the same.

Identification & Life Cycle: Spider mite populations can grow rapidly under the right conditions (warm with little wind is their favorite) and can be identified by the telltale webbing they produce on plant leaves. Unfortunately, by the time you see webbing, it may be difficult to control the population. Spider mites undergo five life stages – egg, larva, two nymph stages and the adult stage.

  • Eggs – Overwinter under bark, in fallen leaf matter, and other areas that provide shelter. During the growing season they can be found on the undersides of leaves. They usually hatch within three days.
  • Larva – Begin hatching after the last frost has passed and have six legs. Little feeding is done by this stage.
  • Nymph – Looks similar to the adult, but slightly smaller and unable to reproduce. There are two nymph stages: proto-nymph and deuto-nymph.
  • Adult – About 0.4 mm long with eight legs, adult spider mites can be pale yellow to green or orange to brown. Females lay between 50-100 eggs throughout their lives with unfertilized eggs hatching as males and fertilized eggs hatching as females.

The duration of a spider mite’s life cycle varies greatly depending on environmental conditions with temperature being the chief contributor to that variability. Due to that, they are most active outdoors during the summer months. A generation can be completed in under a week if conditions are favorable.

Damage Symptoms: Spider mites damage foliage by sucking juices from the leaves. This shows up as stippling on the leaves and more severe damage can result in leaf bronzing that may lead to leaf drop. Leaf drop increases incidence of sun/light burn and negatively affects both vegetative and flowering stages. Additional signs of spider mites are curled and/or burned leaf edges as well as leaves that have taken on a leathery texture. Webbing will be produced when mite populations grow in size and can be found on foliage, twigs and fruit/buds.

Control & Management:

Sanitation – Sanitize your growing environment thoroughly. This includes washing all surfaces of the growing area, selecting organic soil mediums and inspecting plants for mite presence before planting. Remove any webbing prior to moving forward.

Cultural Control & Prevention – Optimize the growing conditions to the crop being grown and the environment being cultivated. Minimize mite damage by reducing water and nutrient stress as much as possible. Therm X-70 can be added to feeding schedules to increase nutrient/water absorption. Anything you can do to help your plants through hot spells will help control mite population growth.

Knockdown & Chemical Control – Existing spider mite populations should be treated with organic knockdown sprays if allowed. Naturally derived miticidal sprays like neem oil, pyrethrins, azadirachtin and horticultural oil can be sprayed directly onto adult mites, larvae, nymphs and eggs to kill on contact. Apply to active spider mite infestations at 3-day intervals until control is achieved. Horticultural oils can also be applied to overwintering sites to reduce egg populations. Exercise caution when applying oil-based sprays to plant in high temperatures (>80°) or intense lighting. Miticides should be used as a last resort in the flowering period of growth. Utilize biological control methods instead (see below).

Biological Control – Ideal for spider mite control during flowering. Introduce beneficial insects after knocking down spider mites for continued control. Match your growing conditions with the mite predator’s optimal conditions and time releases in conjunction with other integrated pest management approaches.

  • Mite Predators – Phytoseiulus persimilis, Neoseiulus californicus, Amblyseius andersoni, Neoseiulus fallacis, Mesosiulus longipes, Galendromus occidentalis
  • Spidermite Destroyers – Feltiella acarisuga, Stethorus punctillum
  • Generalist Predators – Minute Pirate Bug, Ladybug, Assassin Bug, Green Lacewing

Quick Pest Reference Guide

PLEASE NOTE: All Mite Predators require additional processing time due to rearing and collection times. Please make note of the information in red at the top of each mite predator page and in the Shipping Tab to identify the earliest shipment date. If you have questions about shipment dates, orders can be placed with our sales representatives at 1-800-827-2847.

Fungus Gnats: Tiny Flying Houseplant Pests

Q. A friend gave me a large tropical houseplant in December. With it came very small, dark, flying bugs. Is there any non-chemical solution I could spray that might eliminate these little pests? Thanks!

    —Merrily in Severna Park, MD

How can I get rid of gnats on my houseplants and prevent them from coming back? I don’t overwater my plants so I don’t know where they’re coming from. I’ve tried sticky traps, red pepper, water that cigarettes had soaked in (which I heard about on a TV show), insecticidal soap, and Raid House and Garden spray. These gnats are really getting on my nerves! Please help.

    —Valerie in Bowie, MD

Mike: I’ve had a horrible fruit fly problem for six months now. I believe the pests came from an ornamental orange tree, which I removed months ago. I’ve bleached my cabinets and counters and poured vinegar down the drain, but nothing works. Please help!!!! I can’t even enjoy a glass of red wine with dinner without fruit flies landing in the glass!

    —Melissa from Fairfax, VA

A. Wow! It’s toxic home-remedy week here at YBYG!

Melissa—were you hoping to achieve bleached white fruit flies? I’m as protective of my old vine Zinfandel as anybody, but please—everyone—don’t use bleach! Although some addle-brained garden and food writers suggest it for everything short of mouthwash, bleach is dangerous stuff. Its risky to handle, the fumes were used as deadly chemical agents in World War I trench warfare, and it creates cancer-causing dioxins. If you need to disinfect a surface, use soap and hot water. If that’s not enough for your peace of mind, plain old white vinegar kills germs with the best of them.

It also controls fruit flies. Fill little dishes with vinegar (or that red wine that turned out to be too gnarly to drink; ); the fruit flies will drown themselves in the liquid. And just keeping all the fruit and vegetable matter off of your counters for a few days is often enough to break the flies’ very short life cycle.

But you mention that they first came from a potted plant, and that makes me think you are actually a member of our fungus gnat trio—especially if you have other plants in the house that the gnats could have migrated over to. As our good friend Bill Quarles, director of the Bio-Integral Resource Center (www.BIRC.org) in Berkeley, California notes in a feature article in the latest issues of the BIRC’s fine journal, Common Sense Pest Control, “fungus gnat” is an all-inclusive name for a huge number of similar-looking small flying creatures that breed in houseplant soil.

Bill explains that, like whiteflies, the gnats are attracted to yellow sticky traps, which are available mail order and at most garden centers. Place the sticky yellow rectangles on their holders and push the stakes into the soil. As each generation hatches, the annoying-but-harmless adults will get stuck and be unable to mate. When all the luckless gnats have left the soil, your problems will be over—at least till you bring new plants in.

These pests are always being re-introduced because they are epidemic in greenhouse situations. Smart growers now control them with beneficial nematodes, which is also another home cure. Water some of these microscopic predators into your houseplant soil before you release the rest outside to control lawn grubs and flea larvae in your yard.

Or use BTI—the non-toxic, naturally occurring larvicide used in standing water or on wet patches of ground to prevent mosquito and black fly problems; homeowners can use the same BTI to kill baby gnats down in the soil (where they are probably chowing down on your poor plants’ roots!). Almost everyone carries the doughnut shaped BTI dunks, but look for the granular form; it’s best for this use. Or use one of the fungus gnat specific BTI products that are EPA approved for use as soil drenches for controlling the pests.

Or sprout any grain—cat grass from a pet shop, wheat grass, etc.—in a pie plate filled with soil near your plants. The gnats will fly into the lush young grass, which you then throw away. Repeat this until you’ve gone through all the life cycles in the soil.

And while overwatering doesn’t CAUSE the gnats, they do love moist soil, so having a light hand with the water can help minimize the problem. As can a trick that’s 90 years old! As Bill reports, it was discovered back in 1916 that a one-half inch layer of sand on top of the soil is an excellent deterrent to adult egg laying. Prevent the eggs, and you prevent the larvae, and thus the adults. Probably looks nice too.

By the way, if you want to see what those nasty larvae look like, Bill says there’s a newly devised (1997) way to do so. Slice a potato into chunks at least one inch in diameter and one half inch thick, and imbed them in the soil of your houseplants. Remove 48 hours later and look for nasty little quarter-inch long wormy things with black heads.

And finally, remember “Kitchen Sink” Val in Bowie, who said she had tried EVERYTHING to get rid of the pests, including {quote}: “water that cigarettes had soaked in”? Now, you know that I’m always urging allayouse out there to garden without chemicals, but some of these ill-advised “home remedies” are more toxic than the most egregious commercial pesticide. Never soak tobacco products to make nicotine tea!

Cigarettes are bad enough when their smoke is inhaled! Soak them in water you create a very nasty toxic brew that could easily send you to the hospital. Nicotine has been illegal for garden and farm use under federal law for many decades—and for good reason; get just a little bit on your skin and you risk serious and immediate health problems.

Ask Mike A Question Mike’s YBYG Archives Find YBYG Show

Fungus gnats are the tiny black flies that you see buzzing around your indoor plants. There’s nothing fun about them at all, and getting rid of fungus gnats in houseplants can be a bit of a challenge. Thankfully, I’ve got some great tips to help you banish these annoying little bugs for good.

How to get rid of fungus gnats in houseplants: 6 Ways to control fungus gnats in houseplants:

  • Use a hydrogen peroxide & water solution
  • Allow the potting soil to dry out
  • Repot the plant or refresh the growing medium
  • Use yellow sticky cards to attract and trap fungus gnats
  • Apply insecticides to the potting soil
  • Use a biological control agent

While adult fungus gnats are fairly harmless, the larvae can cause damage. Larvae feed on algae and fungi most of the time, but they can feed on plant roots within the soil too, which can lead to root damage and stunted growth. It’s best to get rid of fungus gnats as soon as you notice them. Read on to learn how to effectively get rid of fungus gnats in indoor plants, and how to prevent future infestation.

What Is A Fungus Gnat And How Do They Get In Houseplants?

Fungus gnats are not very big at all. In fact, they only grow to around a quarter of an inch in length. You might think that they are too small to cause much damage at all, but unfortunately their larvae can and will damage your plants.

Fungus Gnats are part of a family of insects that include Bolitophilidae, Diadocidiidae, Keroplatidae, Ditomyiidae, and Diptera. Fungus gnats thrive in moist environments and typically seek them out. Naturally, they are found in damp forest areas and typically feed on mushrooms and decaying plant matter.

Fungus gnats do not hibernate in winter like other insects do, which means that they can be a problem all year round.

As gnat larvae like decaying plant material and algae, they seek out damp environments. Fungus gnats are attracted to the following:

  • Houseplants that are overwatered (waterlogged soil)
  • Bright light (they can be found at windows)
  • Mold and mildew
  • Wet or warm environments

If this sounds familiar, it is time to get to work making your home and garden a less gnat-friendly environment.

An organic way to test for fungus gnat larvae is by using a slice of raw potato. Push slices or wedges of potato onto the surface of the soil and leave them there for a few days. The larvae will start feeding on the potato on the underside of the slice/wedge. Turn the wedges or slices over and see how many larvae have made their way to it. You can use several slices to draw gnats out of your soil.

How To Identify Fungus Gnats

How do you know if your plant really has fungus gnats? After all, they look very similar to small mosquitos or black flies.

It isn’t too difficult to tell if your house plants have fungus gnats. The first and most reliable way to tell is by inspecting the soil thoroughly. If you happen to notice that there are some black flies or insects hovering around your plants, that is a good sign that you have a fungus gnat infestation.

Of course, not all insects and bugs are fungus gnats, so you might need to verify that they are in fact fungus gnats by looking for other tell-tale signs.

Some other ways to identify fungus gnats include the following:

  • Look for Fungus Gnat Larvae. Take a look around on the ground that surrounds your house plant. Do you see any white larvae lying on the ground’s surface? Fungus gnat larvae look like little white specks on the soil. These are baby fungus gnats that have hatched.

Fungus Gnat Larva

  • Take a good look at the condition of your plants. When a plant is being damaged by fungus gnats, there are a few tell-tale signs to look out for. Check if the plant is wilting or withering. A withering or wilting plant could be a sign that fungus gnats have started damaging the root system as they eat their fill in the plant’s potting soil.
  • Check for yellowing leaves or leaves falling off the plant. It is normal for plants to shed their more mature leaves when making way for new foliage. It is not normal if the plant is losing more leaves than expected or is losing both young and old leaves.

When fungus gnats eat the roots of house plants, they typically damage the plant’s feeding system. With damaged roots, the plant cannot get nutrients and water up to the leaves and the rest of the plant. When this happens, the leaves start to turn yellow and fall off.

If your plant has yellowing leaves, check the soil for fungus gnats and inspect the roots for damage. You might be able to save the root system if there are still some healthy root sections left.

  • If you have seedlings, check on their growth rate. Are your seedlings or young soft plants growing at a suitable speed and making the expected progress? If they do not seem to be making the type of growth progress that you expected, you might be dealing with fungus gnats. Fungus gnat larvae can stunt the growth of young plants.

6 Ways To Get Rid Of Fungus Gnats

If you have a fungus gnat infestation, there is a number of things you can do to rectify the situation. Below are a few ways of getting rid of fungus gnats, as listed above.

1. Use A Hydrogen Peroxide And Water Solution To Get Rid Of Fungus Gnats

3% Hydrogen Peroxide is an effective substance for controlling larvae. To get rid of fungus gnats, mix a solution of 1 part of hydrogen peroxide with 4 parts of water.

You should only water your house plant with this solution when the top of the potting medium is dry. When you pour the peroxide solution into the soil, you might hear an effervescent sound.

Once the peroxide has done its job of killing the gnat larvae, it will break down in the soil. It is completely harmless to your plant. While it should work first time around, you might need to repeat the process.

2. Allow The Potting Soil To Dry Out To Get Rid Of Fungus Gnats

As fungus gnats are attracted to damp environments, it is important to ensure that your house plants potting medium is not always wet or damp. It is tempting to water house plants frequently, but you might not be doing your plants any favors if your watering frequency is attracting insects.

If your plants are constantly watered, the environment becomes prime real estate for mold and algae to grow. And by now you already know that mold and algae are two things fungus gnats love. By allowing the top 2 inches of soil to get completely dry between watering, you can create a soil environment that is not fungus gnat friendly.

Before you water your house plants, feel the surface layer of the plant. If it is wet or damp, do not water. If it is dry, you can water. Female fungus gnats specifically seek out soil that is consistently wet. Drying soil deters eggs from hatching into larvae.

Giving your indoor plants the right amount of water is the most important thing you can do to keep your houseplants healthy. It seems like such a simple thing to do, but it’s a skill that you need to develop. I’ve written several articles to help you get this right. Read about ways to tell when to water your houseplants and how often to water your houseplants for more information

3. Repot The Plant To Deter Fungus Gnats

If you have larvae infested soil and do not want to kill the gnats, you can always repot the plant in fresh soil with good nutritive value. Remove the house plant from its container and discard the infested soil. Make sure that you rinse off the roots or shake excess soil from the plant.

All plants have their own sensitivities, so it is important to look up how to best repot the plant you are working with. Once you have cleaned out the container, you can repot the plant.

Make sure that there is no decaying plant matter in containers or near your newly potted plant as fungus gnats can easily spread. Also, be careful to only water the plant as required and not to keep the soil soaked as this will just keep attracting fungus gnats.

4. Use Yellow Sticky Cards To Remove Fungus Gnats

You can use sticky yellow fly trap cards to catch fungus gnats in your houseplants. This is a reliable method to use if you are dealing with an abundant population of gnats. Adult fungus gnats are naturally attracted to the color yellow, which is why fly trap cards are often yellow.

You should be able to find a sticky yellow card product called Gnat Stix online and in local nurseries and stores. To use this method, simply place the sticky cards beneath the canopy of the plant’s pot.

As the gnats make their way towards the yellow card, they will get trapped in the sticky area. This helps to reduce next-generation larvae populations.

Yellow Sticky Card Traps are really effective for dealing with adult Fungus Gnats

5. Apply Insecticides To Get Rid Of Fungus Gnats In House Plants

Many house plant owners want to sort the problem of fungus gnats out as quickly as possible, with insecticide. Different insecticides will be required for the adults and the larvae as they respond differently to treatments. New adults are usually born on the surface of the potting soil, so it is best to apply the insecticide to the soil’s surface.

There is no need to spray the insecticide onto the actual plant as the gnats typically infest the soil and head for the roots and the algae in the soil.

You can choose to use a mild or natural option such as Neem Oil or dish soap, but they are not as effective on fungus gnats as some other commercial options.

If you are looking for highly-effective and reliable insecticides for getting rid of gnats not just immediately, but long term, look for products that contain permethrin, bifenthrin, cyfluthrin, and lambdacyhalothrin.

6. Use A Biological Control Agent To Get Rid Of Fungus Gnats In House Plant Soil

Using insect-parasitic nematodes is a great way to control fungus gnats biologically. An insect-parasitic nematode is a type of roundworm that is invisible to the naked eye. Steinernema Feltiae is a highly effectively parasitic nematode to use when treating house plant soil for fungus gnats.

When used to get rid of gnat larvae, they are poured onto the soil in a solution. The roundworms then set to work destroying the fungus gnats in a fairly disturbing way.

The microscopic worms enter the gnats via the mouth, breathing pores and other orifices and release bacteria that actually digest the gnat from the inside out. It can take up to 4 days for this method to be effective in getting rid of fungus gnat larvae. For all intents and purposes, the fungus gnats are attacked and devoured by these microscopic round worms.

How To Stop Fungus Gnats Spreading To Other House Plants

Fungus gnats like to spread from plant to plant. This means that if you have one infested house plant, you run the risk of infecting all the other house plants in your home too.

The best way to protect your house plants from the spread of fungus gnats is to separate the healthy plants from the infested plants. Quarantining the fungus gnat infested house plants is a good first step.

Start treating your infested plants immediately and consider carrying out the same treatments on your other plants. This can serve as a preventative step, just in case larvae or eggs have found their way into their containers.

How To Prevent Fungus Gnats

Fungus gnats are not a problem you have to deal with only after they have made an appearance. There are things that you can do to prevent them from infesting your house plant’s soil in the first place. Below are a few pointers to help you prevent fungus gnats and keep them at bay.

Keep Plant Debris To A Minimum

Plant debris is a dream come true for fungus gnats. Plant debris is a main source of decaying plant material and this is where adult female fungus gnats love to lay their eggs.

If you notice debris that has fallen from your plants lying in or around the pot, clear it away. These include leaves, flowers, fruit, sticks, and similar. Potting soil that contains compost such as bark should also be avoided as these can trap moisture and include decaying organic matter which is very attractive to the fungus gnat.

Be Careful To Avoid Overwatering

Good drainage is your friend when it comes to keeping fungus gnats at bay. If your plant containers are consistently damp, fungus gnats will find their way to it and make themselves at home.

Do not overwater your plant and if you find that the soil itself does not drain well, add some perlite to the mix to help with absorption and drying out.

When you do water your plants, make sure that no water is left in the saucer beneath the pot. Empty these out no more than 30 minutes after the plant has been watered.

Plan your watering schedule carefully. Follow the care instructions for your plants and avoid watering until the soil is suitably dry. You can push your finger into the soil to feel if it is dry enough before watering. It is quite important to keep the top layer of your potting soil dry as this will deter fungus gnats from laying their eggs.

Last Word

Getting rid of fungus gnats can be tricky, but with these tips, you should be well on the way to getting rid of them. A lot of the process of keeping fungus gnats at bay is your watering schedule. Adjust that and you shouldn’t be pestered by these bugs at all. Make sure that you are creating a living environment that is ideal for your house plant and not the pests that seek to destroy it.

How to get rid of gnats is one of the most popular topics on GetGreenBeWell.com. The number of comments that I get from frustrated gardeners who have infestations of fungus gnats on their house plants and outdoors is surprising! Gnats on plants is a serious problem and it’s driving y’all crazy.

Trust me. I know.

I had a major gnat problem because I bought this type of bagged soil – even though it was organic.

The gnats that came out of that potting soil drove me crazy!

Or maybe you have gnats on your plants for some other reason.

Either way, the flying little bugs are annoying.

They can also seem impossible to kill. Especially if you don’t want to be spraying potentially toxic chemicals in the air of your home trying to catch the little things.

Until now.

I’ve noticed my readers are gravitating towards three certain types of non-toxic gnat control with products that kill gnats naturally. These products sell again and again each month.

So I wanted to share with you what other home gardeners are doing to kill gnats on their houseplants and inside the home, as well as gnats in the garden outside.

How to Kill Gnats: Three Ways

There are different methods of killing gnats. They are:

  • Systemic (meaning that you put something in the soil to kill gnats from reproducing)
  • Sticky Traps
  • Sprays

All of these different ways of how to get rid of gnats work. It depends on your preference, and how much time you want to spend in taking care of the problem.

For instance, systemic treatments might work more effectively over the long term, but they’ll take several days to see results.

Sticky traps and sprays will work immediately, but you’ll probably have to use them frequently until you get rid of the source of the gnats.

These methods of how to get rid of gnats can all be non-toxic. The sticky traps are among the most non-toxic. You don’t have to worry about sprays in the air or mixing solutions.

The systemic options are smart, too, because you add them to the soil, rather than spray. There is less chance in exposure to the product if it goes in the soil and you don’t touch it (or pets or children don’t play in it).

The sprays are among the gnat control products that you would have the most possible exposure to, as far as inhalation. Be sure to choose one with natural ingredients, such as the option below.

How to Get Rid of Gnats in Your House

These are among the most effective products to kill gnats. I’ve used them all and have had great success in different ways.

Removing the source of the gnat infestation is always the best way to kill gnats. But sometimes you don’t know what the source is, or can’t remove it. Then these products will work to kill gnats.

Sticky Traps

I tried to resist sticky traps for quite a while, because I didn’t want big yellow things in my houseplants. But what I’ve found is that over time I don’t even look at the yellow traps anymore. And I can arrange them behind a leaf or trunk to hide the yellow traps.

What we did find is that these yellow sticky traps for gnats work crazy good! It’s so simple. And it’s a leave it and forget it solution, which I love.

Plus, there are no chemicals or pesticides on these sticky traps for gnats. There are no worries about pets or children being exposed to nasty ingredients accidentally. Gnats are just attracted to the yellow, and the sticky tape catches them and prevents them from flying off.

Just adding one trap can catch gnats for weeks to come. After a couple months, my stick traps were still sticky and attracting gnats.

The amount of gnats in my home after bringing in new houseplants decreased dramatically!

I used this brand of gnat sticky traps and really love it (you don’t have to buy the multipack unless you have a lot of plants or gnats).

(Who knew, right?!?)

Mix This In Your Soil: Systemic Gnat Killer

Adding a biological larvicide that kills fungus gnats’ larvae is the perfect way to kill any future gnats. If you can wait out the life cycle of any gnats that have already started flying around, then a systemic insecticide is a smart choice.

These products are mixed into water or sprinkled on top of the soil. The biological control prevents fungus gnats from breeding. This is important because while you might feel like you won by killing the gnats flying around your home, there could be more gnats about to be released from potting soil that you can’t see.

Then it’s a never ending battle.

These biological controls aren’t insecticides. They simply alter the breeding ability of the gnats to prevent them from becoming a nuisance. You might be familiar with this type of systemic product in controlling mosquitoes. There are mosquito dunks that you can add to pools, fountains, bird baths, etc. that naturally prevent mosquitoes from breeding. This is the same type of product.

I have used these granules in my potting soil to prevent fungus gnats from breeding. I really do think that it worked. After a week or so, there seemed to be less problems with pesky gnats in my house. Keep in mind, this product says Mosquito Bits but it also states on the label that it works with fungus gnats.

Gnat Spray for Plants

Sometimes you just want a spray to kill problem bugs immediately and on contact. After all, no one wants to wait for a sticky trap or systemic gnat killer to work when they are entertaining in an hour.

Thankfully, there are safer insecticides that use the power of plants and nature to kill bugs, including gnats.

I’ve used Garden Safe products with great success. If you’re looking for a spray to kill bugs on contact and when you specifically see them, then this insect spray is a good choice.

More Houseplant Tips

Here’s some great ideas on how to keep plants alive when you’re away on vacation.

Dirty plants aren’t healthy plants. Make sure you know how to clean plants for better air purifying.

Here’s the answer of how plants purify the air, in case you were curious.

If you’d like to improve your indoor air quality, be sure to sign up for my FREE COURSE on the 3 Best Houseplants to Detox Your Home.

Best Houseplants to Detox Your Home

And if you’re looking for better sleep tonight, consider adding one of these best plants for the bedroom. And check out this amazing place to buy plants online (some of the best detoxing plants can be found here for a great price!).

How Do I Get Rid of Gnats in My House?

Question: How do I get rid of gnats? I’m pretty sure they are gnats at least. They are really, really tiny and look like black dots. I bought a house spray and have been spraying about 4-6 times a week. They are only in my kitchen at the base of my back door. I can’t tell where they are coming from. What must I do? P.S. My home is new construction. Would this be a factor?

Answer: If you have gnats in the house, it usually means the presence of one or both of these small flies:

FUNGUS GNATS

If the flies are small, black, and flying around windows or potted plants; then they are probably fungus gnats. These flies are the most common small fly in houses. They are small, delicate black flies that are weak flyers and often collect at windows. The immature stages are small and maggot-like, but with dark brown heads. They live in the soil of potted plants. The immature stages feed on the decaying organic material in the soil. They generally do no harm to the plant roots.

The larvae are common in the moist soil of the plants that have been overwatered and the soil remains wet or very moist. This may occur in the fall when plants are brought inside for the winter, or in the winter when house plants (or office plants) are overwatered. Read more about gnat control.

Gnat Illustration

FRUIT FLIES

If the flies are small, light brown and seem to be attracted to places in the kitchen, then they are probably fruit flies. To control these flies you have to start with the removal of overripe fruit and vegetables; this is where the larvae live. To remove the adults, which can live for a few weeks, you can place a small amount of vinegar in a shallow pan, and place this pan in locations where the flies are common. They are attracted to the vinegar and some may get trapped in the liquid, and you can use an aerosol to spray the others that are waiting there. Read more about fruit fly control from Orkin.

fruit fly illustration for in the house

PHORID FLIES

If the flies are small, light brown to black, and have a rather jerky or erratic walking behavior when they are on a surface (they run in a zig-zag rather than a straight line) then they may be phorid flies. These are sometimes called sewer flies. They are similar in size to fruit flies, but the walking separates them, and they seem to be active at night, while fruit flies are not. Phorid flies usually have a direct connection to a broken sewer line (inside or outside the house). If these are the flies you have, it is best to get the sewer or septic tank system looked at. Read more about phorid fly control

Phorid fly illustrationphorid fly illustratoin for in the house

Related Questions:

The Orkin Man used the information above to also answer the following questions submitted by Orkin.com users:

  • Question: I live in the 60136 area, and I have a BIG problem with gnats. I can’t open my windows ever! I even had the pests during this past winter when I opened my window “just a little bit.” I don’t want to be turning on my air conditioner just to get crisp fresh air! What can I do?
  • Question: I have small black flies in my home. I notice them in the bathroom and on the window sills. We recently bought two new house plants and it seems that most of the flies are in the same room. I have done research, I think they are gnats or fruit flies (no fruits lying exposed). Can you help me identify what type of flies I may have? Also, what measures can I take to get rid of them?
  • Question: How can I kill gnats? How much is your service usually?
  • Question: I have gnats, I think, and I want to know how to get rid of them or how much it would be for you to get rid of them. They are out of control.
  • Question: We have these pesky, small flies. We have no fruit plants. They seem to come from nowhere and we don”t know how to get rid of them without getting rid of our plants or destroying them in the process.
  • Question: I have these tiny green bugs with wings that I keep finding in one room in my house. I find them dead in the windows, around the floors and on the top of the table. They look like a super tiny mosquito. ANSWER: These are probably midges that are active this time of year (outside) and are attracted to lights at night … so it might be helpful to turn off outside lights.
  • Question: What can I do about “gnat” bugs? I have a ton of them on my front door and around my windows at night.
  • Question: I have these small flies in my bathroom and kitchen areas. They are very small and they show up in bunches and die within a day. I clean the areas but they are back the next day in small amounts and build up.
  • Question: My apartment has been invaded by these tiny flying insects (I think they are gnats). They don’t bite, they’re just very annoying and are now getting into my refrigerator.
  • Question: How do you control little flying gnats?
  • Question: What can we do to get rid of gnats in our office?
  • Question: My apartment has become a home to these tiny flying insects. I don”t know what they are, I just call them gnats. I don”t believe they are mosquitoes because I don’t see or feel any bites on me. They buzz by my ear, making that tiny high-pitched buzzing sound. I have killed at least 30 of them, but they are next to impossible to catch and kill. I’ve been swatting at them with anything I can find. I first started noticing them in my bathroom, but now they have taken over the entire place. I know they are crawling on me as I sleep and I can”t handle that! I want to have someone come out and get rid of them! What are they, and what should I do?
  • Question: I have a problem with tiny flying gnats. They are very small—smaller than fruit flies. I have them year round. They are attracted to light and white surfaces. I live in Ohio and there are woods about 50 feet from my house.
  • Question: Where do gnats come from? Do they live in the fruits?

Tags: Flies

Our Pest Library

Find out more about your suspects

Our Pest Library is full of up-to-date information on termites, ants, and cockroaches as well as more than 25 common household pests. Find out more information about their behavior, habits, and other cool facts.

Ask Your Question

Still didn’t find an answer to your question? Fill out the form below and we’ll get right back to you with an answer. For service and billing questions please message us here.

Fungus gnats lay eggs in the houseplant soil. The eggs become larvae, which feed on fungi in the soil of plants, hence their name. The fungus gnat larvae are around 1/4-inch long with a shiny black head and an elongated, whitish to transparent body. In addition to fungi, they also like organic matter and will sometimes eat plant roots or seedlings, leaving plants wilted. A slime trail that looks like traces of slugs or snails across the top of the soil is another telltale sign there are gnats in your houseplants. The gnats also like light, so you may notice them on your windows, particularly if houseplants are nearby.

The first indication of gnats in houseplants is a sign to take action. While it may be tempting to spray the adult fungus gnat, that’s often a short-term fix. More adults will appear from the larvae in the soil. A better approach is to target the larval stage of their life cycle. Because gnats lay their eggs in the moist soil around houseplants, reducing excess moisture is a key to getting rid of these nuisances. Avoid overwatering your houseplants and make sure they have good drainage. Allow the soil to dry between regular watering — not to the point that your plant begins wilting but enough that the soil isn’t continually moist. The eggs and larvae usually die in dry soil. Remember to drain any excess water that may have accumulated in saucers.

If drying out soil does not seem to help, you might try a product such as Gnat Stix, which are yellow sticky traps. Place the trap near your plants to trap the adults and thereby reduce the number of eggs the fungus gnats lay. Be careful to avoid touching the plant leaves with the sticky paper. Check the traps every few days and replace when they become covered with gnats.

Fungus gnats are often more noticeable in the fall. It may be that they hitchhike on houseplants when they are brought indoors at the end of summer. Before bringing plants inside, check them to make sure they are free of insects. Before you purchase new plants, examine them to make sure there are no insect infestations. Use a sterile potting mix when planting or repotting.

This article originally appeared on www.bhg.com.

How to Get Rid of Fungus Gnats

Getting rid of fungus gnats is all about consistency. Catching the adults is fairly easy, but because the adult population comes in cycles, you need to make sure that your traps are refreshed regularly. For the best results, use a combination of the traps listed here as well as the additional preventative methods listed in the subsequent section.

  • Sticky cards: These traps consist of a yellow note card covered in a sticky adhesive. They are most effective when cut into small squares and placed directly on top of the soil or attached to skewers just above the soil. Adult gnats will fly or crawl onto the card and become trapped. Fungus gnats are attracted to the color yellow, so use the yellow sticky cards rather than the blue ones. Both can be bought at most hardware or garden stores, as well as online.

  • Cider-vinegar traps: Simple and effective, cider-vinegar traps consist of a shallow container with a small amount of apple cider vinegar, water, and liquid dish soap.

    • To make a cider-vinegar trap: Find a shallow container—a tuna can is perfect—and fill it with equal parts water and apple cider vinegar. (The liquid should be at least ¼-inch deep.) Put a few drops of liquid dish soap into the mixture and stir gently. Place the trap near the base of the affected plant or, ideally, inside the pot on top of the soil. Check it every few days to refresh with new vinegar and water.
  • Diatomaceous earth: Diatomaceous earth (DE) is an organic, abrasive powder that works well on fungus gnats. The powder sticks to the gnats, dehydrating and immobilizing them. Use “food-grade” DE, which is available at most garden and hardware stores. Read more about diatomaceous earth.

    • To use DE: Dust the soil surface with DE, especially around the inside edges of the pot and the base of the plant. DE should only be applied when the soil is dry—otherwise, it will soak up moisture and won’t stick to the gnats. In our experience, using DE on top of a layer of sand (see below) and watering from the bottom of the pot has been most effective.
  • Flypaper: Flypaper ribbons, such as those hung in horse barns to catch outdoor flies, can also be used to catch fungus gnats. However, these traps are usually overkill for gnats and can easily get stuck to things you don’t want them to stick to, such as furniture, hair, plants, and so on.

How to Prevent Fungus Gnats

Use these prevention techniques in tandem with the traps listed above for the best results.

  • Keep soil dry: Fungus gnats seek out moist soil, so allowing your houseplants to dry out a bit between waterings can slow down or stop an infestation. Let the top inch or two of soil dry out before watering again, and try to go as long as possible between waterings. Gnats may be deterred from laying their eggs if the soil is dry on the surface.

  • Mosquito dunks: Mosquito dunks are used to keep mosquito larvae from populating fountains, animal troughs, fish ponds, and other small bodies of water. The product consists of a dry pellet containing a type of bacteria called Bacillus thuringiensis subspecies isrealensis. This beneficial bacteria infects and kills the larvae of flying insects, including mosquitoes, fruit flies, and fungus gnats.

    • To use mosquito dunks: Fill up a gallon jug (or watering can) with clean water and toss in a mosquito dunk. It’s a good idea to break up the dunk a bit before placing it in the water, or you can wait for it to soften before breaking it apart. Let the dunk soak in the water for as long as possible (at least overnight), then remove it from the water (the dunk can be reused) and use this water for fungus gnat–infested plants. The bacteria will have leeched into the water and will now infect and kill any larvae that come into contact with it in the soil. Repeat this process every time you water your plants for at least a few months.
  • Sand layer: Put a half-inch layer of coarse sand on top of your houseplant’s soil to stop adult gnats from laying eggs and new gnats from emerging from the soil. Consistent coverage is key. Be sure to water from the bottom of the pot, too; otherwise the sand will just wash away.

  • Cover drainage holes: Though gnats typically remain near the tops of pots, they may find their way to the drainage holes on the underside of a pot and start laying eggs there, too. If this happens, cover the drainage holes with a piece of synthetic fabric to prevent the gnats from getting in or out of the hole, but to also let water pass through freely. Attach with tape or rubber bands.

Do you have any tips for preventing or stopping fungus gnat infestations? Tell us in the comments below!

Leave a Reply

Your email address will not be published. Required fields are marked *