Bugs on rose buds

How do you control aphid attacks on a rose bush? Here’s the scene!

It’s springtime and after a long weekend, coffee in hand you visit your heirloom rose bush collection. All your eyes see are the flower buds of your beautiful roses covered with aphids, including the Knock Out roses.

It is not in a small area or in small numbers but overnight it appears the entire aphid population attacked your rose garden.

You know if this aphid infestation is not dealt with, the sap-sucking pest, feasting on the plant juice of new growth, flower buds and rose stems will soon become:

  • Distorted and crippled flowers
  • Leaves and stems get covered with sooty mold as the aphids excrete a sweet sticky substance called honeydew all over even the undersides of leaves.
  • A plant that attracts ants which protect and farm aphids
  • Gnarled and curled leaves
  • An entire rose bush plant with less vigor

The first questions many new to battling aphid attacks are:

  • Where do you start in the control of rose aphids?
  • What chemical or natural sprays will get rid of the aphids?
  • What natural enemies will eat aphids lunching on the rose bushes?
  • Mostly, how to kill aphids on roses?

Before you grab the killing sprayer, let’s take a moment for some education.

Contents

What Species Of Aphid Bugs That Eat Roses?

First, there are various species of aphids (100’s) which attack all kinds of plants.

  • Oleander Aphids
  • Apple Aphid
  • Green Peach Aphid

However, there are a couple of species which fancy rose bushes.

The two “rose aphid” insects are the:

  • Macrosiphum rosae (Rose aphid)
  • Macrosiphum euphorbiae (Potato aphid)

When Do Aphids Come Out And When Do You Start Spraying For Aphids?

Here’s a “Master Gardener” tip: Nature gives aphids a “feeding” head start every spring.

When temperatures start to reach 50° degrees Fahrenheit, these insects “come out” and begin to hatch.

The warm spring weather arrives and new growth begins to emerge, the plant juices start flowing, the live young begin feeding, and the population starts to increase reaching their peak in early summer.

Predators like Aphid lions and cute, voracious Ladybugs along with others do not begin to hatch until temperatures average 60° degrees Fahrenheit.

This allows populations a solid 10 to 14 days to become established before the beneficial “bugs” can begin their work.

Don’t wait until the garden is full of insects. During this 10 to 14 day period apply sprays to keep the insects in check and keep the colony from growing too large.

Holding the pest in check until the predators get going, helps maintain an even balance.

This reduces the need for spraying. Plus, the sprays will not wipe out the pest or harm beneficial insects.

  • How To Control Thrips In Gardens
  • When Should A Pesticide Be Applied To Control A Pest?

How To Get Rid Of These Pests

Many home gardeners start their insect control by pulling out the garden hose and hit the new colony of young aphids feeding on the new growth with a strong water spray.

While this home remedy of blasting the colony with water works for starters with many types of plants, we don’t recommend that approach with roses.

When these conditions come together: Water + Moisture + Rose Leaves all come together they add up to Powdery Mildew or Black Spot.

Instead of getting the entire plant wet, why not opt for one of the natural spray solutions.

What Chemical Or Natural Sprays To Use For Rose Aphids?

Both chemical and natural spray options will work in controlling these insects but the best insecticide for roses will depend on a few things which we’ll dive into below.

However, we always want to exhaust all the options to reduce and control white aphids populations on roses organically before pulling out synthetic chemicals like Malathion, Acephate (Orethene), Merit® 75W and others.

To answer your question, “how do I protect my roses from bugs?” take a look at these sprays.

Natural homemade spray for roses include:

  • Insecticidal soap solution
  • Liquid Dish Soap Spray
  • Neem Oil
  • Horticultural Oils
  • Rubbing alcohol

Insecticidal Soap

This insect killing soap is not a hand-washing dish soap or detergent.

A true soap like “Castile soap” contains fatty acids. These acid dissolve or remove the cell membranes and the natural waxy protective coatings of soft-bodied insects causing death from dehydration and excess water loss.

These insect soaps can be a home remedy or purchased ready-made. Here’s our recipe for insecticidal soap or buy the Safer soap band.

Liquid Soap Solution Spray

This spray is a simple homemade solution fine for use on small outbreaks.

Two ingredients are all that is required:

  • Water
  • Dish soap – like pure liquid castile soap, without any additives (like chemicals, moisturizer or fragrance)

Follow these steps:

  • Use a sprayer or small clean spray bottle
  • In one quart of water mix in 1 tablespoon of soap. For a one-gallon spray solution add 4 to 5 tablespoons to a gallon of water.
  • Mix thoroughly and use immediately.

For best results, evenly coat infected plants including the underside of leaves. The insects need to come in contact with the soap-spray to be effective.

Neem Oil

Neem oil is one of our favorite natural pest control options for aphids, scale insects, spider mites, mealybugs and a host of other garden insects.

The oil has a low toxicity for animals and humans along with being a powerful deterrent to unwanted insects.

Neem oil is a useful natural insecticide against soft-bodied insects, but it also interferes with the feeding activities of larger, tougher insects such as beetles.

Though this article is focused on controlling white aphids on rose bushes, Japanese beetles and other pest attack roses as well.

More on Using Natural Neem Insecticide To Control Scale, Aphids, and More

Horticultural Oils

In general, use horticultural oils as your last option for controlling these pests.

Oil sprays use to be heavy. Today, these horticultural oils are refined and “lightweight.”

Most of these oils are safe for use on many plants throughout the growing season as new colonies of pests appear.

The oil is applied, dries up and is non-toxic to plants, but very effective in pest control.

The phrase “dormant spray” refers to the timing of when to use the oil and not the type of oil utilized.

Always follow the application directions on the insecticide label.

Look for products with these “labeled terms”:

  • Dormant oil spray
  • Volck oil
  • Dormant spray
  • All seasons spray oil
  • Summer oil

For more read our article: What Is Horticultural Oil And How To Use It In Gardens

Rubbing Alcohol

A cotton swab and 70% rubbing alcohol has long been a home remedy for controlling insects.

Take a cotton ball swab dipped in rubbing alcohol, and dab it directly on the insects to kill them.

To make a rubbing alcohol pest spray mix 1/4 cup of alcohol with 1 cup of water.

Place the solution in a small, clean spray bottle and spray the insects on infected plants.

NOTE: Beware that the leaves on some plants may burn. To treat roses apply on cloudy days.

WARNING: Can You Make A Homemade Spray To Get Rid Of Aphids With Vinegar? Yes! But Don’t

If you search the web you’ll find the “recommendation” of mixing vinegar and water in a spray bottle to kill aphids.

The mixture will kill the insects on contact but will also do some damage to your roses and other plants sprayed.

If you want to kill weeds use the vinegar spray but NOT on your roses.

What Natural Predator Insects Will Kill or Eat Aphids Attacking My Roses?

Many people when they hear the word “bug” assume all bugs or insects are bad. Not True!

There are lots of many good insects (beneficials) waiting for the opportunity to rid your garden of “bug” and lunch on some pests.

Timing is important when using “natural enemies” if the food source is not available they will leave and hunt elsewhere or die for lack of food.

A few natural predators for controlling these bad insects include:

  • Ladybugs or Lady beetles
  • Green Lacewings
  • Hoverfly
  • Parasitic Wasps

Ladybugs or Lady beetles

The cute little-spotted lady beetles (ladybug) are voracious insect predators and the best-known enemy of aphids.

Both larvae and adults actively prowl gardens during the day hunting for soft-bodied “true bug.”

Once spotted, the cute ladybug uses its powerful jaws to grasp and consume their prey.

In fact, egg-laying adults can gobble up two hundred of these insects per day.

How To Use Lady Bug In Gardens

Green Lacewings

The green lacewing earned the name “aphid lions” because of their aggressive voracious appetite.

After hatching, the lacewing larvae begin searching for garden pests to consume with a favorite delicacy – aphids.

These “eating machines”, are constantly hunting for the next meal.

If they encounter a slow-moving, soft-bodied insect or their eggs – they will eat it.

Learn To Use Green Lacewings For Gardens Pest Control

Hoverfly

Hoverflies larvae often are found in the midst of a colony devouring their prey.

The larvae love soft-bodied pests like thrips, aphids and plant scale. Hoverflies are also excellent pollinators.

The hoverfly takes second place to the lady beetle or ladybug with their capability of wiping out large numbers of aphids.

Learn Natural Control With Beneficial Hoverflies

Parasitic Wasps

Parasitic wasps may be tiny but are important natural control agents.

These wasps, live a portion of their lives inside other insects as parasites. They vary in color and size but are usually black or brown and small to medium in size.

In general, parasitic wasps do not sting and provide natural biological control of other insects.

The wasp lays their eggs inside the bodies of these insects using their ovipositor, a pointed egg-laying structure.

The young parasite eggs hatch and begin feeding on the contents of their “host,” killing it.

Two parasitic wasps common in gardens are:

  • Aphidius colemani (Braconid wasp)
  • Ichneumon Wasp

Pest management is the key to insect control for your roses and other plants in gardens.

  • Learning when aphids feed
  • Knowing your control options
  • Understanding when sprays are the most effective without killing off the good insects.

You have many options available for keeping aphids on your roses under control. It’s learning to use the tools and maintain the balance.

How to Get Rid of Aphids on Roses

Roses are one of the most popular perennial landscape plants. They thrive in warm summers, frequent rainfall, and moderate winters. Unfortunately, ample rainfall and warm summers are also favorable conditions for the growth of pests. The most common diseases that affect the growth of rose plants are aphids, black spots, powdery mildew and rose rust. My rose bushes are afflicted by aphids nearly every year. And although I regularly spray my garden with insecticides, aphids seem to always find their way back into my garden. So what exactly are aphids, and how can we get rid of them? Keep reading to find out!

Aphids

Aphids are tiny, soft-bodied insects that appear in a wide range of colors, ranging from yellow to light-green, pink, red, brown and even black. Most species of aphids have a woolly exterior coating, an elongated pear-shaped body with a pair of long antennae and a pair of exhaust pipe-like structures called cornicles protruding from the hind part of their body.

Aphids prefer to attach to young, succulent shoots and feed on plant phloem. Phloem is plant tissue made up of specialized cells that transport food from the leaves to the rest of the plant. And aphids use a specially adapted mouthpart called stylets to pierce the plant tissues and reach deep into regions where the phloem is located. They feed on the sap and assimilate the soluble organic nutrients present in it.

Aphid reproduction

Unlike other insects, aphids have a unique way to increase their numbers and colony size. Their reproduction shuttles between asexual and sexual phases and is controlled by seasonal changes. Once the spring arrives, fertilized overwintering aphid eggs hatch into wingless females, attach themselves to a host plant, and feed on its sap for sustenance. These wingless female aphids, after attaining maturity, reproduce asexually to give birth to young female aphids. This asexual reproductive phase continues throughout summer resulting in the formation of a huge aphid colony of aphids from a single female aphid. At the end of summer, aphids switch into a sexual mode of reproduction, which begins by giving birth to both male and female aphids. The male aphids are winged insects that mate with female aphids and produce several hundreds of fertilized overwintering eggs. These overwintering eggs stay in the soil and hatch after the winter season ends. The male aphids then fly to a new plant in search of food carrying several young wingless females with them and deposit themselves and their female companions on healthy young plants to repeat the growth cycle.

Impacts of an aphid infestation

As the aphid colony increases in size, the health of the host plant starts to deteriorate rapidly. Aphid infected flowers and fruits become distorted. Leaves infected with aphids turn yellow and begin to wilt or curl. Aphids also excrete a sugary liquid called “honeydew”, which sticks to the plant and attracts ants. On top of also encouraging the growth of a sooty mold, which makes the plant shoots appear black and sooty. And the stressed plant is also prone to several secondary infections and may eventually die if the aphid problem isn’t treated in a timely manner.

How to get rid of aphids on roses: control & preventative measures

  • Prune infested plant shoots: Start with a simple approach. Cut off the branches showing signs of an aphid infestation (like wilted and curled leaves). When cutting the branches, make sure that the infected branch does not land on an adjoining healthy branch or a nearby healthy plant because you do not want to transfer the aphids to new host plants. Carefully discard the cut portions of the plant in a yard waste collection bag. And store the bag as far away from your plants as you can.
  • Water jet: Spray the shoots of your roses with a jet of cold water to dislodge the aphids from the infected plants. Repeat the process every few days to remove the last traces of aphids from your rose plants. Focus on the underside of leaves because aphids tend to hide in those places. It is recommended to use this strategy in the mornings, so as to allow enough time for the leaves to dry throughout the day, because if left moist overnight, leaves may develop fungus.
  • Dust with flour: Dust your rose plant with a generous amount of flour. Even though aphids ingest the flour, they cannot digest it. Undigested flour clogs their digestive system and causes death. This approach is especially useful when the rose bush is young and cannot withstand the force of a powerful jet of water. Dusting with flour may also be used against aphids when the infestation occurs on flower buds and young shoots.
  • Mild dish soap solution: Spray the leaves of your roses with a mild dish soap solution. Apply once every 2 to 3 days and continue this practice for at least 2 weeks. Alternatively, you may choose to wipe the leaves with the solution instead of spraying it on.
  • Insecticidal soap: People also often use diluted insecticidal soap solutions to spray on their rose plants to get rid of aphids. Usually, the labels of such products claim that they do not harm beneficial insects. Well, the fact is that insecticidal soaps, once used in a garden, affect all insect species alike. So, refrain from using this option for milder infestations that can be treated using other methods.
  • Introduce natural predators: Ladybugs, green or brown lacewings, blister beetles, soldier beetles, damsel bugs, midges, and hoverflies are all-natural aphid predators. You can, therefore, purchase a small bag of these beneficial insects and introduce them to your aphid infested rose garden. They will rapidly devour the aphid colonies on your rose plants effectively getting rid of aphids on roses and leaving your plants healthy and thriving.
  • Kill overwintering eggs: Spray Neem oil, horticultural oils or other environmentally friendly oils on the soil in your garden during the fall season. This will help eliminate the overwintering eggs of aphids.
  • Companion planting: If you do not have an aphid infestation on your rose bushes currently but want to prevent a possible aphid infestation in the future then a good preventive strategy is to plant catnip, garlic, or chives near your rose bush to deter aphids. This approach of growing certain plants in close proximity to other plants that either repel pests or attract pollinators is called companion planting.

You could apply any of these aphid infestation prevention and control strategies depending on the needs of your garden and the level of the aphid infestation. For serious and recurring infestations, either uses a combination of these strategies or seek help from a professional pest control company.

Q & A: How do I protect my roses from aphids?

SALLY TAGG Aphids suck sap out of new growth on roses and distort bud formation.

Q: The buds of my roses are covered with aphids. The blooms are all distorted when they open. What can I do to protect my roses?

A: Soft, sappy new growth on roses and other plants attracts aphids. There are various species of aphid and most are specific to particular groups of plants. They’re a menace because they transmit viruses with their needle-like mouthparts, and sooty mould grows on the honey dew they excrete.

Aphids cluster at the tips of new growth so a quick, effective control is to squash them with your fingers. Aphids are targeted by ladybirds and other beneficial insects and insectivorous birds so attracting these to your garden will help knock back aphid numbers. Aphidius colemani, a parasitic wasp (from zonda.net.nz), also predates on aphids.

* Start a vege garden: getting rid of weeds
* Start a vege garden: beating pests

Sprays need to be used very carefully because if they kill aphids there’s a good chance they’ll kill beneficial insects like bees and other pollinators too. Spraying with Neem oil knocks back the aphids but won’t harm larger beneficial insects. Mineral oil or pyrethrum kills aphids – but it harms good bugs too.

Be selective when applying; target only pest-infested areas or individual plants. A windless evening is the best time to apply sprays if bees are active during the day. Spray affected plants every five to seven days until infestations are under control. With all sprays, test on a just few leaves first to ensure your plants do not react negatively to them.

These DIY spray recipes have natural ingredients but that doesn’t mean you shouldn’t be just as careful applying them.

1. SOAP SPRAY
The fatty acids in soaps dissolve the exoskeleton of aphids, whiteflies, thrips and mites and they dehydrate. Use a liquid soap, such as castile soap, which contains no fragrance or other chemicals. Add 1 tablespoon soap per 1 litre water and shake. It needs to come into contact with pests to work.

2. TOMATO LEAF INSECTICIDE
Tomato foliage contains a poisonous alkaloid known as solanine, which is deadly to many pests, including aphids. Place foliage in an old food processor, cover with water, add 2 tablespoons cornflour and mix. Strain before using on roses and other ornamentals.

3. CHILLI & GARLIC INSECT REPELLANT
Knock back infestations of aphids and other soft-bodied insects and deter them from coming back with this potent mix. Wear gloves when making this, as the chilli can cause skin irritation and pain if it gets into your eyes. Blitz 5 cloves garlic and 1 habanero chilli (fresh or dried) in a blender with ¼ cup of water until well chopped. Steep for one hour. Strain through a fine sieve. Discard the solids, then mix the liquid with 750ml hot water and ¼ teaspoon soap or dishwashing liquid. Transfer to spray bottle.

NZ Gardener

  • Twitter
  • Whats App
  • Reddit
  • Email

Rose Aphids

Whether you have one rose in your garden or hundreds….you need to know how to control annoying aphids that cluster on the buds and growing tips. But rather than use an insecticide, let nature do the work. It’s better for the environment and the biodiversity of the garden.

Aphids are tiny sap sucking insects usually about one to two millimetres long that appear when the weather warms. Colonies can build up very quickly. They eat developing shoots and flower buds by piercing the plant’s surface and sucking out the plant’s juices, which can result in deformed buds, flower loss and even defoliation of the plant. They do not just affect roses. Peach trees and hibiscus are tasty treats for aphids too.

There are chemical-free ways of dealing with aphids. The first strategy of aphid control is the most environmentally friendly, and that’s to let nature do the work for you. Shortly after the aphids appear, watch for the appearance of the aphid’s natural predators. The best-known of these is the ladybird. And the ladybird larvae, which look a bit like a crocodile and eat more aphids than the ladybirds themselves.

Other natural predators of aphids include hoverflies and their larvae, lace wings and small birds. By having a healthy garden and not using chemical sprays, these predators will be present.

In the early 1990s, scientists at the Waite Agricultural Research Institute at the University of Adelaide introduced a specific biological control method for the rose aphid. It was released in the rose garden at Urrbrae House. It is a tiny little parasitic wasp called Aphidius rosae . This tiny little wasp has spread and is now found around South Australia, Victoria, New South Wales and possibly further afield. It’s found in gardens provided excessive amounts of insecticide haven’t been used.

The wasp is tiny and is often not visible. But look for evidence of mummies. These are where the wasp lays its egg – inside the body of the aphid, then it eats it out from the inside and leaves a shiny brown paper-like skin. These mummies can be found clustered among the aphids, under the leaves and on the rosebuds. When the adult wasp is ready to emerge, it chews its way out of the mummy through a neat hole.

Many people believe that even using a relatively low toxic environmentally friendly insecticide, such as pyrethrum or garlic spray, is a good way of dealing with aphids. But unfortunately those sprays are non specific and will kill natural predators too.

Ultimately the best way to control aphids in your garden is to build up the health of your plants by feeding, mulching and watering appropriately. Happy, healthy plants are more resistant to pests. So let nature do the work for you and within a couple of weeks, your garden and the environment will be stronger for it.


Rose Aphids are small green, brown or pink sap sucking insects which are approximately 2.5mm long. They appear in clusters and can be winged or wingless. Aphids infest the soft tips of new growth, leaves and flower buds and can cause deformed flowers, the wilting of shoots and may even defoliate the plant if left untreated. They usually appear during Spring and Summer and can build up their numbers very quickly due to their prolific breeding. During the warmer months Aphids produce live young that develop into adults within weeks mulitplying the colony seemingly overnight. Rose aphids will only inhabit roses and will not attack other plants in your garden.

Treatment

At the first sign of Aphids, use a hose to spray the affected rose making sure you spray above and below the leaves. Aphids hate water and will soon move on.
Remove Aphids by hand. Rub your fingers up and down the buds to squash and remove them.
Encourage natural predators to the Aphid, such as: Hover fly larvae, ladybirds, lacewings, parasitic wasps and red and blue beetles.
It may be necessary to spray roses with an insecticide or Eco Oil. Remember that the aphids also lay eggs on the plant and a repeat spray may be necessary a couple of weeks after the first. Please use chemicals sparingly as they also kill the good insects and natural predators as well as the one you are trying to get rid of – always look for a natural alternative before using chemicals! Aphids have a short life cycle, having many gererations in one year, therefore they can become immune to a certain chemicals if used too often, try changing sprays with different active ingrients for best results.
Try using a garlic or chilli spray. Take two teaspoons of crushed garlic or chilli and put into 500mls of water. Let this sit for a couple of days so the water is very potent. Strain and spray onto the plants. Although this home remedy is highly effective it will need to be repeated each week for a couple of weeks or after it has rained.
If you do know you will have aphid troubles then please consider companion planting. Aphids dislike garlic, chives, mint and lavender. Roses grown with companion plants are much less prone to aphid attacks.
Important: signs and symptoms will vary significantly between varieties, even within similar categories. The information provided here is a basic summery of the most common affects and will not always be applicable to all rose varieties.

This post contains affiliate links. Read my full disclosure.

Springtime means the landscape is greening up and flowers are finally in bloom…yes, even here in the desert Southwest. I grew up in the Midwest, so I know that’s hard to believe. Here’s photo proof from a corner of my backyard.

My Beautiful Roses

My very favorite plant is my lovely Pope John Paul II rose bush. I picked this rose out from hundreds nearly 3 years ago for Mother’s Day. I’m a frugal and practical person, so my thinking was it is a better use of our money to buy a plant that will keep producing flowers rather than accepting a one-time bouquet. Honestly, I did not have high hopes for the survival of this bush. It is really hard to keep things alive through our hot summers! My expectations were low.

Happily, I was wrong and roses are some tough plants! We get a high yield of fragrant and gorgeous blooms to enjoy! They are pretty straightforward to care for, and planting in the right spot is half the battle. From my experience, pests seem to be the biggest thing about roses that can make them high maintenance.

What are those tiny green bugs?

Of the pests I have encountered, aphids are among the most unsettling. They are tiny, crawling green bugs that huddle up on the green base of the rosebud, along the stem, and on the underside of the blooming flower. They blend in using darned camouflage so that until you take a closer look, you might miss them. Then much to your horror, you notice the tiny army camped out on your gorgeous flower you are on your way inside with. Eew!

How do you get rid of them?

Luckily, you can quickly get rid of aphids on your roses. You do NOT need dangerous chemicals to do it! In fact, a strong spray of water from the hose is enough to dislodge these critters. However, they will come back if you only use water. Oil or soap mixed with water is often the natural recommendation you will hear. These substances kill the insects on contact rather than acting as a poison, so they must be sprayed directly on the aphids.

Why not use Dawn or Murphy Oil Soap?

Dawn dish liquid is frequently recommended for an aphid plant spray. However, Dawn is not great for the environment as it has been shown to cause harm to aquatic creatures and pose a risk to humans. The other soap you may be advised to use for this purpose is Murphy Oil Soap. This too has chemicals in it that are cause for concern for humans who use it as well as for the environment. EWG rates both a “C.” These are examples of how you cannot assume that something is safe and nontoxic simply because it is commonly used in homes.

A Truly Non-Toxic Aphid Spray For Your Roses

Castile soap is a natural and nontoxic plant-based soap comprised of several different oils including hemp, olive, and coconut. EWG rates it an “A” with low/no concern for toxicity and harm to the environment. If you saw my post on Green Cleaning DIY | The Ingredients You Need, you may already have some Dr. Bronner’s Pure Castile Soap at home. This is the key component in the aphid rose spray that I use. I add peppermint oil as an insect repellant to keep the aphids from returning, but it is not necessary to actually kill the aphids. The water and castile soap do that.

Ingredients

  • 2-3 cups of water
  • 2 T Dr. Bronner’s liquid castile soap (any variety)
  • 10 drops of peppermint essential oil

Simply mix all of your ingredients together in a spray bottle. Spray all over the underneath side of each flower, making sure that you thoroughly spray any visible aphids. Since aphids feed in particular on tender new growth, be sure to coat any newly forming buds with the solution as well.

Keeping a close eye on your rose bush during the blooming season is really the best defense for the pests that can harm your rose. About once a week, or at the first sign of aphids, give each bloom a spray to keep the little buggers away. Aphids are no match for this rose spray!

Pin this post to your gardening board for later!

145shares

Fighting Common Rose Pests

Roses are always a popular topic for Master Gardeners’ free gardening helpline, operated by the University of California Cooperative Extension, as well as various workshops and educational programs.

In this second column of a multi-part Q&A series, we discuss how to tackle some of the most common pests that attack roses, and their natural predators.

Question

Help! My roses are being eaten by insects. How can I protect my roses without frequent applications of pesticides?

Answer

Insects and mite pests can cause havoc in a rose garden. They can blacken leaves, chew blossoms and leaves, distort blossoms and cause leaves to stipple or yellow. Pests can even make rose canes die back. That’s the bad news.

The good news is many rose owners maintain strong, healthy plants bursting with blossoms, with little to no insecticides. This is especially true of Ventura County’s dry interior valleys. The secret lies in selecting the right varieties for your area, tolerating minor insect damage and adopting good gardening practices.

Number-One Nuisance: Among roses, aphids are the most common pest. These hungry insects feast on rapidly growing plant parts such as buds and shoots, especially in spring and early summer. In moderate to high levels, aphids secrete large amounts of honeydew, which can cause a sooty mold that blackens leaves. In very high levels, aphids can kill rose buds or reduce flower size.

Tackle aphids before they become a serious problem. First, wash aphids off plant with a strong stream of water early in the day, so the foliage dries before evening. If that doesn’t work, try insecticidal soaps or neem oils, which only moderately affect the aphid’s natural enemies.

Fortunately, aphids have many natural enemies, including lady beetles, green lacewigs and parasitic wasps. Control ants around your roses with sticky barriers on canes to encourage more lady beetles. If you purchase lady beetles at the nursery, mist beetles and plants with water before releasing the insects. For best results, release beetles at dusk and place them on canes at the base of plants. Don’t be surprised when most fly away, especially after the aphid population is reduced.

Stippled or Yellow Leaves: Are your leaves bleached or stippled, with webbing? You may have spider mites. Often when the spider mites’ natural enemies have been killed by broad-spectrum pesticides, these tiny mites will increase in number. To reduce this pest, wash leaves periodically. If stronger controls are needed, try insecticidal soap, horticultural oil or neem oil.

In some areas, rose leafhoppers can be a problem. The stippling is larger in this case, and there is no webbing on the leaves’ undersides. Insecticidal soap will help.

Distorted Blossoms: If blossoms become distorted or streaked with brown, the culprit may be thrips. These tiny yellow or black insects prefer fragrant, light-colored or white roses. They also like numerous rose bushes planted together, because this provides a continuous-blooming habitat for their dining pleasure. To reduce these pests, clip and remove spent blossoms regularly.

Chewed Blossoms and Leaves: Several pests chew flowers and leaves – from Fuller rose beetles that leave ragged edges on leaves to leafcutter bees that cut semicircular holes. Rose slugs look like tiny caterpillars, but are the sluglike larva of a sawfly. Young rose slugs can skeletonize lower leaves, while larger ones can chew large holes. A strong stream of water or insecticidal soap will help reduce these pests.

Dead Rose Canes: Flatheaded borers lay eggs on diseased and stressed rose canes. The white larvae can kill canes or an entire plant. Another pest is the raspberry horntail, which also lays eggs on rose plants. The larvae can cause canes to wilt and die in spring, reducing the second bloom cycle. Scale insects cause small, grayish, round to oval encrustations on rose canes. For all these pests, remove and destroy any infested plant material. Insecticidal soap on remaining canes helps protect plant from further damage.

Gardener’s Friends: Minute pirate bugs, lacewigs and lady beetles are some of the natural predators of rose pests. Keeping a healthy garden, encouraging plant diversity among your roses and tolerating minor insect damage can go a long way towards attracting more of these natural enemies.

More Help: Want more rose gardening tips? The University of California Division of Agriculture and Natural Resources has information on beneficial insects as well as common rose pests and mites (Pest Notes, Publication 7466). Visit www.ipm.ucdavis.edu for a copy.

Free gardening advice is available by calling the Master Gardener Helpline at 805/645-1455. The helpline is staffed Tuesdays and Thursdays, 1-4 p.m.

Author: Teresa O’Connor is a Master Gardener with the Ventura County Cooperative Extension. For more information on the Master Gardener program, contact 805/645-1455.

Rose pests and how to control them organically

This post may contain affiliate links. If you click on an affiliate link and make a purchase, we receive a small commission at no extra cost to you. Find our full disclosure here.

Roses are a favorite landscape plant of many homeowners. Their beautiful blooms are classic show-stoppers. With so many long-blooming, low-maintenance roses on the market these days, you would think there would be no need for an article discussing common pests of roses. But unfortunately, while there are plenty of rose varieties that are resistant to common rose diseases, such as black spot and powdery mildew, there’s no such thing as a rose that’s completely resistant to insect pests. Even low-maintenance rose varieties face pest issues. I’d like to introduce you to eight critters who make holes in rose leaves, distort foliage, and destroy flower buds. I’ll also share some tips for managing them safely.

You don’t need synthetic chemicals to grow beautiful roses. Choose natural pest solutions instead.

Why use organic rose pest solutions

Before introducing the pests themselves, it’s important to understand why the kind of pest control you use is critical to your garden’s overall health. Yes, rose pests are a common complaint of rose-loving gardeners, but with pollinator populations on the decline, it’s important for us to choose organic rose pest solutions, rather than synthetic chemicals that could harm other wildlife.

Many popular rose pest control products are granular systemic pesticides that are sprinkled on the soil around the base of the plant. They are then absorbed through the plant’s roots and travel up into the foliage. These products include active ingredients that move through the vascular tissue of your rose plant, killing whatever nibbles the leaves. This might seem like a good thing at first because systemic products are easy to use and long-lasting. Eventually, however, systemic pesticides make their way into the pollen and nectar of the plant, where they bring harm to the pollinating insects visiting the blooms.

Neonictinoids, roses, and pollinators

The most common systemic pesticide ingredient used in rose pest controls in the United States is the neonictinoid imidacloprid. Neonictinoids have made news recently for their negative impact on pollinators and other non-target insects. Avoid systemic pesticides at all costs when controlling pests on roses and other landscape plants. These products also end up in the food chain when birds, frogs, toads, and other creatures eat the insects that have ingested the pesticide. They also harm soil life and will likely harm birds, pets, and any mammals who eat the granules.

Truth be told, there’s no need for any of these toxic pesticides anyway. As you’re about to learn, there are many organic rose pest controls that are effective and safe to use, and will not bring harm to non-target wildlife.

The first step in growing healthy rose bushes is learning to identify common rose pests.

8 Common rose pests and how to control them

There are hundreds of different species of aphids in North America. They’re found from coast to coast in nearly every climate, and on most other continents as well. Aphids are tiny, pear-shaped, soft-bodied insects measuring up to 1/8″ long. They can be green, yellow, brown, red, gray, or black. Some species have winged forms; others do not. At the hind end of each aphid are two small, tube-like structures called cornicles.

Here, aphids are clustered on the flower stem of a rose.

There are many different plants that host aphids. Roses are among the most susceptible. Aphids damage roses by feeding on the leaves, stems, and buds. These rose pests use a needle-like mouthpart to penetrate plant tissue and suck out sap. They feed in groups on new plant growth or on leaf undersides, and cause stem tips, new leaves, and buds to be curled and distorted.

At my house, I completely ignore aphids on all of my plants. Within a week or two of noticing them, the beneficial insects always find the aphids and bring them under natural control before they cause significant damage to my roses and other plants. If the infestation is severe and no beneficials show up, remove aphids with a sharp stream of water from the hose. This knocks them off the rose plants and onto the ground where they’ll quickly be found by ground-dwelling predatory insects, like spiders, ground beetles, and others. Hand-squishing is also effective. But, as I said, most of the time, predatory beneficial insects naturally bring aphid populations under control.

Product control is seldom necessary for these rose pests, especially if you interplant your roses with sweet alyssum, which lures or shelters in many of the beneficial insects that eat aphids. But, if your rose aphid infestation is severe, horticultural oils or insecticidal soaps work well.

This convergent ladybug is dining on an aphid in the garden.

2. Rose sawflies (rose slugs): Rose pests that skeletonize leaves

If you come out to your garden and find your roses with holes in their leaves or completely skeletonized leaves, check the plants for rose sawflies. Rose sawflies are tiny green caterpillar-like larvae that measure a mere 1/8″ to 3/4″. They have light brown heads. Also called rose slugs, they are not true caterpillars or slugs, but rather the larvae of a type of fly.

Rose sawflies are very destructive. They can quickly skeletonize the leaves.

You’re most likely to find rose sawflies on the undersides of leaves. They’re very small when they first hatch, so they can be tough to spot. Look carefully on the undersides of the leaves. If sawflies are the rose pests to blame, hand-squishing works, but it takes a lot of time. Again, inter-planting roses with flowers like sweet alyssum, dill, fennel, wallflowers, and cosmos, attracts parasitic wasps, tachinid flies, and other beneficials that control them naturally.

If your roses are being decimated by this pest, product controls with the active ingredient spinosad are very effective (such as Monterey Insect Control and Captain Jack’s). Though they are safe to use even on certified organic farms, spinosad-based products may harm pollinators if misused. Spinosad is a fermented bacterial product that is labeled for use on many common leaf-chewing garden pests. For spinosad to work against sawfly larvae on roses, the tops and bottoms of all leaves must be covered.

3. Thrips: Bud-destroying pests of roses

Rose thrips (Western flower thrips, in particular) are tiny (1/20″), slender, brown to yellow insects that cause flower buds to become distorted or streaked with brown. They feed by sucking out cells. When feeding on leaves, they leave behind silver streaking. Gardeners are likely to find dark specks of excrement on thrips-infested rose plants. It’s so sad when rose thrips strike, not only because they destroy your blooms, but also because they’re quite difficult to control.

Thrips tend to be worse in landscapes where roses are planted in large swaths. Since thrips feed inside rose buds as well as on the leaves, controlling them is very challenging. To confirm an infestation, shake your rose buds and leaves over a sheet of white paper and look for the insects. If you suspect they’re hiding out inside the buds, cut a distorted bud apart and look inside for the tiny insects.

Western flower thrips often feed inside flower buds and prevent them from opening. They also feed on plant foliage. (photo courtesy of bugwood.org/Whitney Cranshaw)

To control thrips on roses, encourage thrips-eating beneficials, like green lacewings and minute pirate bugs, by planting a diversity of plants around your roses. In severe cases, consider purchasing minute pirate bugs from an insectary and releasing them onto your rose plants. Prune and destroy any damaged buds. If damage is severe, spinosad-based organic insecticides, as well as neem oil-based products, are effective, though they offer limited control on any rose thrips found inside the buds.

4. Slugs: Slimy pests that chew holes in rose leaves

Slugs chew ragged-edged, random holes in rose leaves. Their damage is most severe during wet growing seasons. These mollusks are rose pests that excrete a slimy coating on which they travel. If you see slime trails, along with holes in the margins or center of rose leaves, slugs could be the problem. To confirm, head out to the garden at night with a flashlight and inspect the rose bushes. Slugs typically “work their magic” at night.

To control slugs on roses, encourage birds, snakes, salamanders, toads, frogs, and ground beetles to make a home in your garden. Water in the morning so rose foliage dries by nightfall.

Copper strips can be wound around the base of rose canes to deliver a mild shock to slugs who touch it. Slug baits containing iron phosphate are extremely effective and much safer to use around kids and pets than baits containing the synthetic chemicals metaldehyde or methiocarb. If you’re looking for more ways to manage these slimy rose pests, check out this article detailing 8 organic slug controls.

5. Japanese beetles: Day-feeding rose destroyers

While Japanese beetle grubs feed on the roots of your lawn, the adult beetles use over 300 different plants as dinner, including roses. These rose pests are most problematic east of the Mississippi, though areas to the west face Japanese beetle issues, too. Unfortunately, their range is spreading. They feed during the day and are unmistakable.

Japanese beetles are unmistakable. They feed on rose plants during the day.

Japanese beetle adults are copper-colored with a green head. They raise their rear legs when disturbed in a defensive posture. As they feed on roses, these beetles release a pheromone that attracts more beetles, so early and steady control is a must.

Handpick adult beetles and drop them into a jar of soapy water. Better yet, cover your rose plants with a layer of floating row cover or tulle for a week or two after you spot the first beetle of the season (typically in mid-summer). Japanese beetles are active for only 4 or 5 weeks each season, so temporarily covering the plants prevents the most damage.

The best organic spray product for adult Japanese beetles on roses is spinosad. Again, use spinosad-based products with caution and only as a last resort. Never spray when pollinators are active.

6. Spider mites: Minute rose pests that discolor leaves

These super-tiny rose pests may be difficult to spot, but their damage is very distinct. They’re found across much of North America and on most other continents as well.

Spider mites spin a fine webbing on leaf undersides and between stem tips.

Measuring just 1/20″ long, you need a hand lens or magnifying glass to confirm spider mites are the rose pests you’re dealing with. Spider mites have 8 legs and spin a fine webbing as shelter. The webbing is easily spied on leaf undersides and between stem tips. If you suspect spider mites on your roses, tap a branch over a sheet of white paper and look for tiny specs crawling on it. Their damage appears as mottled, yellow foliage.

Once spider mites have been confirmed, your first (and best!) line of defense is the many beneficial predatory insects that help control them. Spider mites are a favorite of ladybugs, predatory mites, minute pirate bugs, and big eyed bugs. Again, add lots of other flowering plants around your roses to encourage these good bugs.

Here,a sachet of predatory mites (Amblyseius andersoni) is hanging on a rose infested with pest spider mites. The predatory mites leave the sachet and prey upon the spider mites.

Since some chemical pesticides actually stimulate mite reproduction, avoid them completely. If spider mites get wildly out of control, turn to horticultural oil and insecticidal soap, both of which are highly effective after two or 3 applications.

7. Rose scale: Tiny “bumps” that weaken plants

Like other species of this pest, rose scale is challenging to control. This species looks like white or grey-white bumps along the stems. The thick, crunchy shell of rose scale makes it resistant to most pesticides. Rose scale overwinters as eggs that hatch in the spring.

Damage from this pest of rose bushes is weak growth and restricted flowering. It’s easy to see the tiny bumps on the stems of your roses when scale is present. Often the leaves are covered with gray-black sooty mold, which grows on the excrement of the rose scale insects.

Rose scale is most vulnerable about four weeks after they hatch (typically in mid June) because at that time, their bodies are soft, having yet to form the hard coating (a life-stage called the crawler). A properly timed application of horticultural oil suffocates them in their crawler stage. You can also spray during the dormant season to smother overwintering eggs.

Release predatory ladybugs, such as this tiny scale predator (yes, this little guy is a species of ladybug!), into the garden to help control certain types of scale.

8. Rose cane borers: Critters who cause cane dieback

Rose cane borers are another pest of roses, though they aren’t as problematic as most others. Symptoms of this pest are wilted cane tips, yellowing foliage, and occasionally, a dead cane. Rose cane borers tunnel into the cane, typically after it’s pruned. You’ll know they’re at work if you spy a hole in the end of a cut rose cane. There are a few different insects that bore into rose canes, depending on where you live. The treatment for these different insects is the same.

The damage rose can borers cause is often insignificant and really nothing to worry about, unless they’ve managed to kill an entire cane. If you’d like, simply cut off the damaged cane, toss it in the trash, and call it a day.

Pest-free roses offer year-round beauty to gardens. Colorful roes hips cling to branches all winter long.

Building a mixed rose garden to limit pests

Despite all of these different rose pests, roses are still wonderful plants to grow. Always choose disease-resistant, low-maintenance varieties. As you now know, deterring rose pests starts by planting a lot of different flowering plants in your garden to help encourage natural rose pest control via beneficial insects. Instead of planting only roses, aim for a mixed habitat including lots of different species of flowering plants with varied flower shapes, colors, and bloom-times. The more diversity you have in your landscape plantings, the healthier they will be! And, if the pests still show up to make dinner of your roses, consider yourself armed with the know-how to use safe, effective organic rose pest controls, instead of systemic chemicals. Happy rose growing!

For more on growing roses, please visit the following articles:
The best low-maintenance roses
Growing roses in containers

For more on organic pest control, visit:
Our guide to vegetable garden pests
Organic slug control
Zucchini pests
Cucumber pests

Do you grow roses? Tell us your favorite varieties in the comment section below!

Leave a Reply

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