Plant leaves turning black

Best indoor plants

This is our list of the Best Indoor Plants for your house, they range from adding a pop of colour, cleaning the air to being super low maintenance.

1. Vriesea

Great for adding a pop of colour to the house and as a bonus, its a low maintenance plant too! When watering, only water the crown of the plant, make sure the compost is not watered too much.

2. Sansevieria (snake plant)

Fantastic plant for beginners as it is low maintenance, it removes toxins and releases oxygen back into the air. It grows upwards so is good for small spaces and does not get very big.

3. Cape primrose

Comes in a variety of flower colours and the best place is anywhere they won’t be in full sun The only thing that they can suffer from is over watering!

4. Peace lily

Is one of the top plants for air purifying according to NASA! This has gorgeous shiny green leaves with individual white flowers and can grow to be quite big.

5. Kalanchoë

Is a tropical houseplant that can adjust to different temperatures, comes in a huge variety of colours and is a succulent, so only needs watering once a week, it can survive being in dried soil for a short period of time.

6. Calathea (peacock plant)

Have great striking leaf markings with a lovely purple underside. They thrive in high humid conditions, so this means they need to be misted on a regular basis, otherwise they develop brown tips.

7. Aloe vera

Known as the medicine plant, it’s inner leaf gel is great for bites, burns etc, but make sure you purchase the right plant to do this with. Part of the succulent family, it does not need much watering and needs very little feeding.

8. Orchids

The easiest orchid to care for are the Phalaenopsis, as they can actually take a lot of neglect and really don’t require much from you. They can flower for ages and do best growing in a clear pot in a light space but no in direct sunlight.

9. Monstera deliciosa (Swiss cheese plant)

This is great to fill spaces, it can grow quite tall and the leaves can reach up to 18 inches wide. These too don’t need much attention and can go without being watered for short periods of time.

10. Spider plant

These are the most common and populare houseplant to have, they are very easy to care for and produce lots of new baby plants. This is also a great air-filtering plant so it’s great to pot up the babies and place them around the home.

Remember: water is not enough!

For good growth and flowering, plants need more than just water, they need the right balance of NPK and essential nutrients. So don’t forget plant feeding is an essential part of caring for your houseplants. Miracle-Gro offer a good range of quality plant foods to help you keep your plants healthy and looking great.

Here are quick tips to keep your houseplants happy and healthy. From knowing how often to water to providing the amount amount of light, we’ll make sure your indoor plants not only stay alive, but thrive!

To learn about a specific type of houseplant, check out our Houseplant Growing Guides.

Light

Before you buy a houseplant, make sure your house can provide the amount of light your plant needs. For example, if you buy a cacti, you will need a window that provides bright light.

When you first bring a plant home, it’s normal for the plant to drop a few leaves as it adjusts. If the lighting is to its liking, it will soon adjust.

  • Put plants that can tolerate full sun and bright light thrive in a south-facing windows (examples are cacti, tropical hibiscus, Lantana).
  • Plants that like partial shade or moderate light do best in east- and west-facing windows (examples are fiscus, phildendrons, and bromeliads).
  • Low-light plants in north-facing windows (examples are snake plants and cast iron plants).
  • Plants that require high light levels will do best under a grow light.
  • Most houseplants grown for their flowers need to be within three feet of a sunny window (examples, African violets, gardenias, orchids).
  • All plants require a period of darkness; light exposure should not exceed 16 hours.
  • Rotate plants every once in a while to encourage even growth and prevent legginess.
  • Plants become acclimated to a site so try not to move them from one light exposure to another; if you must, make the change gradual, if possible.

How do you know if plants aren’t getting enought light? The plant will not flower, show little new growth or spindly grow, lose its lower leaves.

On the other hand, if the leaf edges scorch, or the leaves bleach out or appear dull, then the light may be too bright.

Water

Believe it or not, more houseplants die from overwatering than from anything else! Most houseplants can not tolerate soil that is always wet. Some succulent plants (such as cacti or jade) can survive a month or two without watering. Learn the preferences of you rplants.

The first step, of course, is to ensure the bottom of your pot has drainage holes. Otherwise, you will need to repot the plant.

When to Water

  • Starting in late fall, water houseplants sparingly until daylight hours begin to increase again in the new year.
  • The best time of day to water is in the morning, except when it is cloudy or rainy outside and there will no sun. Avoid watering on a fixed schedule; instead, check the soil and water when needed.
  • Water when the roots, in the lower two-thirds of potted soil, begin to dry. Push your finger into the soil of a 6-inch diameter pot to a 2-inch depth. If the soil feels moist, do not water. Repeat until the soil feels dry, then water. Push you finger to a 1-inch depth in smaller pots. (If it is not possible to pushing your finger into the soil, the soil may be compacted and need pourous material or the plant may be root-bound and could benefit from being transplanted.) Alternatively, lift the potted plant dry and then when wet. You may learn to “feel” its needs.
  • Starting in late fall, water houseplants sparingly until daylight hours begin to increase again in the new year.
  • Water houseplants in unglazed clay pots more frequently, as the porous clay will absorb and evaporate some of the water.

How to Water

  • Water plants with room-temperature water. Cold water can be a shock to a houseplant’s roots—like sticking your toes into an ice bath!
  • Use filtered water if your tap water contains high amounts of minerals or chemicals. Fluoride can cause the leaf tips of some houseplants, such as peace lilies, to turn brown.
  • Always water until the excess water drains out of the holes. Even plants that prefer dry soil should be watered this way (just not as frequently).
  • Water gently over the top of the soil; avoid water on the plant leaves or crown. A long-spouted watering can works best.
  • If water is not almost immediately absorbed by the soil, drainage is poor. Mix perlite, vermiculite, or sand into the soil; for best effect, remove and repot the plant in the amended soil, if possible.
  • Watering from the bottom can benefit plants, too. Set a plant pot (that has holes in the bottom) on a saucer or in a shallow pan. Pour water into the saucer or pan to about an inch depth. Add more water as necessary until the surface of the soil in the pot is moist. Remove the plant from the saucer or pan and set it aside to let excess moisture run out.
  • If the soil is exceptionally dry, water may not be absorbed but instead flow rapidly down the sides of the pot and out into the catch basin/saucer, bringing no moisture to the plant’s roots. If this happens, submerge the whole pot in a deep sink or pail full of water until air bubbles stop being released. Remove the plant from the water and set it aside to let excess moisture run out. Consider repotting the plant into a looser medium mix.
  • Mist under the leaves of houseplants frequently to discourage spider mites.

Humidity

Humidity is a tough factor to perfect, as most homes are fairly dry—especially in the winter. Here are some things to consider about humidity:

  • Many of the most common houseplants come from tropical regions, where humidity is naturally high. They will be happiest when the relative humidity is kept at 50 percent or higher.
  • Plants like cacti and succulents can tolerate lower levels of humidity.
  • Group houseplants near each other to form a support group to cope with the low humidity of most winter homes.
  • Place plants in a bathroom or kitcehn where humidity is higher.
  • Set plants on shallow trays of moistened gravel to raise humidity.
  • Pack damp sphagnum moss between pots in plants.
  • Occasionally turning on a humidifier near your plants can be effective at combating indoor dryness.

Fertilizer

Most houseplants respond well to feeding, but be sure to follow the instructions included with whichever fertilizer you buy.

  • Too much fertilizer can be detrimental to a plant’s health, so don’t fertilize more than necessary.
  • In winter, feed sparingly or not at all; houseplants will be especially sensitive to overfeeding at this time of year, when most go into dormancy.
  • Come spring, start to feed plants again. This, along with more hours of daylight, will help to kickstart their growing phase. Continue feeding through fall.
  • A balanced fertilizer (10-10-10) works fine for houseplants, though fertilizers with a higher ratio of nitrogen will promote greater foliage growth.
  • For flowering plants, use a fertilizer with more phosphorous.

Pests

Pests can be a real pain. They usually appear after outdoor plants are brought inside for the winter, or when a new houseplant is brought home.

  • To get rid of bugs in houseplants, push a clove of garlic into the plant’s soil. If the garlic sprouts and grows, just cut it back.
  • Spider mites are apt to thrive in warm, dry houses. Frequent misting under the leaves of houseplants will discourage them. A solution of 1 cup flour, ¼ cup buttermilk, and a gallon of cool water, applied in a mist, is a good organic deterrent.
  • Small flies may occasionally appear around houseplants. These are called fungus gnats and are harmless to plants (and humans) in their adult form, though their larvae can damage young roots. Letting the soil dry out a bit between waterings can discourage fungus gnats from calling your houseplants home.
  • Your houseplants may sprout bugs once brought inside your house because they no longer have outdoor predators.
  • Remove aphids from houseplants with a mixture of equal parts rubbing alcohol and water and add a drop of dishwashing detergent. Apply this to troubled plants with a soft brush.
  • Mealybugs and scale are commonly seen on houseplants. The mixture of rubbing alcohol, water, and dishwashing detergent outlined above works on mealybugs and scale, too. Regular monitoring of your houseplants is key to beating an infestation.

Wintertime Houseplant Care

Even indoors, winter conditions can be tough on plants. Fewer hours of sunlight, drier air, and cooler indoor temperatures can take their toll, so be prepared.

  • In colder regions, houseplants that have been outside for the summer should be brought in in August. A sudden cold spell will be too much of a shock for them to survive. This is also a good time to take cuttings.
  • It’s also good to bring in plants before you start heating your home. This gives them a chance to adjust. Wash them thoroughly before bringing them in to rid them of any pests.
  • You can dig up your rosemary, basil, tarragon, oregano, marjoram, English thyme, parsley, and chives to grow them inside as houseplants. Keep them in a cool, sunny spot, and allow the soil to dry out before watering. Snip off the leaves as needed in the kitchen, but do not strip them completely.
  • Divide and re-pot any pot-bound plants so they will grow well during spring and summer. Prune judiciously to create a compact, attractive specimen.
  • Provide extra protection to houseplants on windowsills if it is very cold. Place cardboard between the plants and the glass. Be sure the plants don’t touch the windowpanes.
  • As houseplants are growing more slowly in December light, cut down on watering by half until active growth resumes. Hold off on fertilizing as well.
  • If your plants seem a little worse for the wear after winter ends, provide them with more sunlight, fresh air, and frequent bathing.

More Houseplant Care Tips

  • Add a few drops of ammonia to one quart of water used for houseplants; it will improve foliage color and increase growth.
  • Save the water from cooking pasta. Let it cool, then use it to water houseplants. The plants will appreciate the starchy supplement. (If the soil of your houseplants get algae, loosen the dirt in your pots periodically.)
  • Open the doors and windows when temperatures permit to give your house a change of air. This will benefit you and your houseplants.
  • Re-invigorate your houseplants by removing the top ¼ inch of soil and top-dressing with fresh potting soil.
  • If your houseplants’ leaves grow dusty, gently wipe them down with a wet paper towel. Too much dust can clog a plant’s stomata (pores), making it harder for the plant to “breathe.”

Do you have any tips for taking care of houseplants? Share them in the comments below!

Signs of Disease in Common Houseplants

Disease Symptoms: What To Watch For

When disease attacks a plant, it’s easily visible. Growth slows, stunts or becomes spindly; leaves may yellow, show white powdery blotches or develop spots. Affected leaves eventually drop. Stems may become soft and mushy, with black tissue visible near the soil.

Waterlogged soil – either from overwatering or compacted soil that lacks air pockets – causes roots to suffocate and die, trading their white tubular appearance for a spongy, blackened mess. Root problems usually surface as a plant that remains wilted, even though soil is adequately moist. Slip a plant you suspect is having root issues from its pot. Blackened roots and a sour or ammonia odor are sure signs the root system is unhealthy.

Common Diseases

Learn to recognize these symptoms of common diseases.

Gray Mold: Also called Botrytis; a fungal disease that can attack every part of a plant. Resembles fuzzy Gray Mold. To prevent, faithfully remove dead leaves or flowers from stems and soil, and provide adequate air circulation. Commonly attacks Begonia, African Violet and Cyclamen.

Powdery Mildew: White powder appears on leaves. Powdery Mildew doesn’t kill plants, but greatly weakens them. Associated with poor air circulation.

Leaf Spot: Yellow, brown, black or water-soaked spots appear on leaves. When disease is severe, separate spots coalesce and kill the leaf. Also causes brown dusting on leaves and blooms. Frequently attacks Dracaena and Dieffenbachia. Associated with too-high temperature and humidity; also with poor air circulation.

Root Rot: Early symptoms are wilting and yellow leaves. In severe cases, the entire plant collapses. Associated with poor drainage and overwatering.

Viruses: These diseases manifest as distorted, streaked or mottled leaves, or by diminishing plant growth and flowering. Most viruses are incurable – and many are contagious. If you suspect a virus, isolate the affected plant and provide perfect care to rule out other diseases.

Dealing With Diseased Plants

Follow these steps to prevent disease development and spread.

  • Isolate diseased plants.
  • Wash hands between plants when working with different houseplants.
  • Sterilize tools between plants with a solution of 1 part bleach to 9 parts water.
  • Provide adequate water – don’t overwater or underwater.
  • Double-check light needs; adjust a plant’s location accordingly.
  • Avoid crowding plants. Ensure that air flows freely around plants. If necessary, use a small fan to improve airflow.
  • Give up on the most diseased. Sometimes you’ll need to toss plants you can’t cure.

Diseases That Affect Houseplants

Houseplants create a pleasant atmosphere in our homes; diseases can affect the health and vigor of our plants. Proper care and early detection of diseases will ensure healthy, good looking plants.

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Harmful micro-organisms are always present to some extent in the soil, the air, the water and on plants themselves, but a healthy plant has natural defenses against them.

* Always use sterile potting soil or rooting medium.

* Clean and disinfect old pots with bleach before reusing.

* Keep any gardening tools clean.

* Water plants carefully. Water standing in the crown of a plant encourages fungal or bacterial growth, which may cause stem and crown rot. Water left standing on leaves, flowers and buds may encourage the development of botrytis blight or other diseases.

* Do not overwater plants. Roots which cannot get enough air will die, weakening the plant and making it susceptible to disease.

* Provide adequate ventilation and avoid overcrowding so that each plant receives fresh circulating air.

* Protect plants from cold drafts or temperature fluctuations.

Anthracnose: This disease is caused by the fungi Colletrotrichum and Gloeosporium. The leaf tips turn yellow, then tan, then dark brown. The browning may extend completely around the leaf. The leaves eventually die. Wounding enhances penetration by these fungi.

Anthracnose

Prevention & Treatment: Pick off and destroy infected leaves. Do not mist leaves.

Fungal Leaf Spot: Several fungi can cause leaf spots. Symptoms include small, brown spots with yellowish margins on the leaves. Spots may have a concentric ring or target pattern. Small black dots (fruiting bodies of the fungi) may be visible in dead tissue. Sometimes the lesions run together and the entire leaf dies. The fungi survive on dead and decaying plant matter in the soil.

Fungal Leaf Spot

Prevention & Treatment: Remove and destroy infected plant material. Provide good air circulation around the plants. Avoid splashing water on the foliage since this spreads the fungi.

Bacterial Leaf Spots: Plants infected with bacteria have water soaked spots, sometimes with a yellow halo, usually uniform in size and sometimes with sticky ooze. The spots enlarge and will run together under wet conditions. Under drier conditions the spots do not enlarge but dry out and turn reddish brown, giving a speckled appearance.

Bacterial Leaf Spot

Prevention & Treatment: Remove all diseased plant material. Avoid low temperatures, crowding plants, and spraying or splashing water onto the foliage.

Root Rot & Stem Rot: The fungi Rhizoctonia, Pythium, Botrytis, Phytophthora, Alternaria, and Sclerotinia cause these diseases. With root and stem rot, leaves and stems show a noticeable wilt. Stems may be girdled at or near soil level by a ring of brown or black tissue. Infected roots are brown to black and may be soft. The fungi survive in the soil or on infected plant debris in the soil. Their spores can be spread by wind, splashing water or the moving of infested soil.

Root Rot Stem Rot

Prevention & Treatment: Use sterilized soil and pots. Do not overwater the plants, since too much water increases the occurrence of root rot. If only a few roots are infected, cut out these roots and repot the plant in sterile soil. Fungicides are available, however most indoor gardeners will find that these chemicals probably cost more than a new plant.

Powdery Mildew: The fungus Oidium species causes the formation of a white, powdery growth or dry, brown, papery leaf spots. Initial infections usually come from fungi surviving in dead and decaying plant materials or from airborne spores from wild or cultivated hosts out-of-doors.

Powdery Mildew

Prevention & Treatment: Since the disease develops most rapidly under humid conditions, proper ventilation and not overwatering will help control this disease. Remove severely infected leaves.

The most important element in avoiding diseases on your houseplants is to keep them healthy. Many problems are caused by cultural issues such as too much water, not enough light, too much light etc. Here’s a table with common symptoms and the most probable causes.

Common Houseplant Diseases and Their causes

Symptoms Common Causes
Brown Leaves, Burnt leaf margins

Root injury from overwatering, excess soil dryness, excess fertilizer. Excess exposure to cold temperatures. Low Humidity. Pesticide injury or mechnical injury. Potassium deficency. Root rot disease. Nutrient toxicity (fluoride toxicity)

Pale foliage or yellow leaves Air pollution, gas fumes, insect attack, insufficient fertility especially nitrogen, poor root health due to poor drainage, poor aeration, or pot bound roots
Small pale leaves, spindly growth Light too low, lack of soil fertility, overwatering, poorly drained soil
Sudden defoilation Changes in location, sudden changes in light levels.
Brown, yellow or black spots on leaves

Fungal, bacterial leaf spot diseases, overwatering, sunburn occuring when plants are placed outdoors, chemical spray injury.

Wilting or drooping of leaves of foliage plants that do not recover with watering Poor root health due to overwatering or excess soil dryness.
Crown or stem is soft or mushy Crown or stem rot disease due to overwatering
Roots brown in color, soft or rotted Poor root health from overwatering, excess dryness, excess fertilization. Root rot disease.

If you notice in the chart above, 6 of the 8 causes list overwatering as contributing to the problem. More houseplants are killed or damaged by overwatering than any other cause.

A few other things that I do to keep my houseplants healthy:

Stop fertilizing during the winter months; the reduced daylight slows the plants need for food.

Once a year slip the plant from the pot, if it’s root bound repot it. When repotting move up one size; for example, if it’s in a 4 inch pot move it up to a 6 inch pot.

Keep it away from heat ducts during the heating season.

If your home is extremely dry, place some pebbles or marbles in a shallow dish, add water and set your pot on top of the pebbles. This added humidity will keep the leaves from drying out.

Every 6-8 weeks put your plants in the shower and let tepid water flow over them for 5 minutes. This will flush any salts or minerals that tend to build up in the soil as well as flush any dust from the foilage. I like to capture rain water to use on my plants, this eliminates salt or mineral buildup.

Photos courtesy of: Ohio State University, Clemson University and University of Maryland

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