Rose pests can pose a significant threat to the hard work and dedication of gardeners, and their presence can be disheartening to discover.
But fear not, we’ve compiled a comprehensive list of common rose pests along with effective methods for control.
Join us as we learn to identify and control various rose pests including aphids, Japanese beetles, rose slugs, ground slugs, caterpillars, rose leafhoppers, cane borers, rose curculio, earwigs, rose chafers, and leaf rollers.
1. Aphids
Aphids can be divided into four categories:
1.1. Green Peach (Myzus persicae)
Green peach aphids have light green bodies with a round, tapered shape reminiscent of a peach.
1.2. Melon (Aphys gosyppii)
Melon aphids come in a variety of colors, ranging from light green, dark green, yellow, and white.
These aphids have winged and wingless varieties, both measuring between 1/4” to 1/2”.
1.4. Potato (Macrosiphum eupborbiae)
Potato aphids are long and slender as opposed to the stereotypical round, pear-shaped body that most other aphids have.
These aphids come in pink with a red stripe and pale green with a dark green stripe.
1.5. Rose Aphids (Macrosiphum rosae)
Rose aphids have both wingless and winged varieties.
Winged rose aphids range from pink to green with distinctive black markings on their small bodies.
Wingless aphids have spindle-shaped bodies with long antennae. Their bodies range in color from green, to pink, and reddish brown.
Whether they are adults or larvae, aphids are a problematic pest for your roses.
Aphids in their larval stage are even smaller, about 1/8”.
They have a slug-like shape and their body tapers at the head.
Aphid larvae are bright orange, making it easy to spot them on your plant leaves.
Aphids congregate in clusters and usually infest new rose growth and on the underside of young leaves.
You will most likely find aphids infestation between May and early June.
Damage
Aphids suck the nutrients out of the rose plants.
They consume too much sap and excrete a sugary liquid known as “honeydew.”
This secretion coats the foliage of the rose plant and develops into a black, moldy fungus that blocks the leaves from receiving adequate light.
As a result, these leaves drop prematurely.
Aphids can stunt and deform the blooms of roses, reducing both the quality and quantity of the rose plant’s production through prolonged exposure.
Control Methods Against These Rose Pests
Control methods of aphids include:
Applying an insecticidal soap solution to the affected areas. You can make your own at home by combing 1 quart of water with 1 teaspoon of dish soap.
Use diatomaceous earth, a powder made of fossilized sea creatures, as an effective deterrent against aphids.
However, do not apply this while flowers are blooming, as diatomaceous earth can also deter vital pollinator insects.
2. Japanese Beetles
Japanese beetles are slightly larger than aphids (1/2” long).
Their bodies are a metallic green hue with brown wings.
Their larvae are 1 1/2” long white creatures with dark heads.
Damage
Both stages of Japanese beetles are problematic for roses, however, it is the adults that directly impact the roses.
Beetles primarily will go after the flowers and their buds.
When the flowers have been depleted, they will turn their attention to the leaves.
Control Methods Against These Rose Pests
Adult beetles are large enough to be picked off by hand and dropped into a bucket of soapy water.
Applying rotenone pyrethrum is also helpful in reducing the beetle population.
Controlling the larvae is a good preventative measure and stops them from developing into adult beetles.
The Japanese beetle lays its eggs in the grass.
To exterminate the larvae, you can use predatory nematodes for a short-term fix, or milky spore bacteria for a long-term solution.
3. Rose Slugs
Rose slugs are 3/4” long, and pale green in color.
Their heads are brown, as opposed to the blackheads of the oblique-banded leaf roller.
Damage
These rose pests completely devour the leaves of your plants.
Rose slugs eat the leaves until there’s nothing left but a skeleton of the leftover veins.
Rose slugs appear at night, which helps them slip under the radar of most gardeners.
Control Methods Against These Rose Pests
Using an insecticide that is effective for days is needed to control these slugs.
Apply rotenone or diatomaceous earth to the entirety of the rose plant, paying careful attention to the areas that have already been damaged by the slugs.
4. Ground Slugs
Ground slugs can be a few inches in length and are often brown in color.
Just like the rose slugs from the previous section, these rose pests only come out at night to feast, so they will be difficult for you to spot in the act.
Damage
Ground slugs climb up the base of the rose plant and feed from the lower leaves of the bush.
These slugs will leave behind a trail of slimy residue and the affected leaves will have a ragged appearance.
Control Methods Against These Rose Pests
Some gardeners have had luck by leaving out a dish filled with beer overnight.
Other gardeners prefer the classic diatomaceous earth sprinkled across the base of the plants.
5. Caterpillars
Caterpillars are one of the easiest rose pests to spot.
They are often a light green color and can be found feasting on the leaves of the roses, particularly around the edges of the leaves.
Damage
Despite their small size, caterpillars are capable of devouring a large number of leaves in a small amount of time.
They work their way from the bottom of the plant, all the way to where the flower buds are.
If left to feed, caterpillars will start to burrow into the rosebuds.
Control Methods Against These Rose Pests
Caterpillars are large enough that they can be picked off by hand and crushed.
This is the easiest, fastest, and most direct way to eradicate caterpillars.
Do not spray the plant with water as this does nothing to deter the caterpillar.
Diatomaceous earth, rotenone, and pyrethrum do work against caterpillars, but the results are not immediate.
By the time these insecticides are effective against caterpillars, these rose pests will have devastated your plants.
6. Rose Leafhopper
The rose leafhopper is small (1/4” long).
It is wedge-shaped and white to yellowish-green in color.
They tend to congregate around the underside of leaves.
Damage
Rose leafhoppers, like aphids, are sap-sucking insects.
They attach themselves to the leaves of the rose plant and suck out the nutrients.
What is left behind is a collection of tiny yellow stippled dots that cover the leaves.
A continued infestation will cause the leaves to wilt and turn brown, thus causing premature leaf drop.
Control Methods Against These Rose Pests
Spraying the leaves with insecticidal soap will help prevent rose leafhoppers from attacking your plant. Be sure to pay close attention to the underside of the leaves where these rose pests are most likely to be lurking.
7. Cane Borer
The cane borer is a skinny black beetle with a bright red head.
Damage
As their name implies, these rose pests attack the rose plant via their canes.
Their primary target is 6 to 8 inches from the tip of the cane.
There, the cane borer will burrow itself into the branch.
This causes the canes to wilt and fall off the plant.
The cane borer’s larvae will live inside the cane and feast on the plant.
Control Methods Against These Rose Pests:
Because the cane borer lives inside the rose plant, topical solutions such as insecticidal sprays and powders will be useless in this scenario.
The best control method here is to prune the affected canes.
Cut the cane a few inches below the infestation mark.
The infestation mark appears as two parallel lines 1/2” to 1” around the circumference of the cane.
Once you’ve sliced off the cane, inspect the end of the cane.
The wood should be smooth and solid.
If it is still hollow, then that means that there are still larvae deeper in the branch and more pruning is necessary.
8. Rose Curculio
The rose curculio is a type of weevil that is very easily identifiable despite its small stature.
With a length of 1/4”, the rose curculio’s body is red on top and black on the underside.
It has a long snout that is used to feast on roses.
Small, white larvae are also known to pose a problem for roses.
Damage
Rose curculios use this long snout to burrow into the rose buds, specifically.
They feast on the buds, resulting in these buds never coming to bloom.
The rose curculio larvae also enjoy feasting on rose buds and seed pods.
Control Methods Against These Rose Pests
Larvae infestations can be dealt with swiftly by pruning any affected areas.
Dispose of the pruned branches by wrapping them in a plastic garbage bag and disposing of them.
Adult pests can be handled using diatomaceous earth, rotenone, and pyrethrum.
9. Earwigs
Earwigs measure about 3/4” in length.
Their bodies are reddish-brown in color and their shape pincers at the rear.
Damage
Earwigs are one of the least harmful rose pests on this list.
On rare occasions, these pests have been known to snack on rose buds or leaves.
Earwigs are more interested in hiding rather than making the trek to your rose plant.
Control Methods Against These Rose Pests:
The easiest way to control earwigs and prevent them from going after your roses is by putting down a thick layer of mulch to the base of your roses.
The mulch will provide any earwigs will food and shelter, eliminating their need to infest your rose plants.
10. Rose Chafer
The rose chafer is a 1/2” long gray beetle.
Rose chafers are slow-moving and won’t try to escape if you disturb them.
Damage
Just like the Japanese beetle, the rose chafer deposits its larvae into the ground, and the larvae feasts on the grassroots.
An adult rose chafer enjoys feeding on the rose flower and bud.
Continued exposure causes any undeveloped buds to die off before they bloom.
Bloomed roses that have been consumed are unsightly to look at.
Control Methods Against These Rose Pests
Rose chafers are relatively large insects and can be picked off by hand if they happen to be spotted.
Because of their slow-moving nature, hand-picking is the easiest method.
Chemical approaches to exterminating adult rose chafers also include diatomaceous earth, rotenone, and pyrethrum.
The larvae can be stifled with a sprinkling of milky spores or a predatory nematode.
11. Leaf Rollers
Leaf rollers are a rarer rose pest, but sometimes they will take up residence on your rose plant.
They are pale green with black head.
Leaf rollers get their name from their practice of rolling themselves in a leaf for protection.
They release silk that secured the leaf around their body.
Damage
The leaf roller will feast on all parts of the rose plant, including the flower, bud, and leaves.
Long-term infestation causes severe damage to the plant and makes the rose plant look aesthetically pleasing due to the damage caused by prolonged feasting.
Control Methods Against These Rose Pests
Most sprays are ineffective against leaf rollers because they use that leaf as a sort of armor.
The most direct method of controlling leaf rollers is by singling them out on the plant and crushing them between your fingers.
You can also use dormant oil sprays as a preventative to deter future populations of leaf hoppers.
Fungicide can also be mixed into these dormant oil sprays in order to also deter fungal diseases.
Apply this spray in the early spring to canes that survived the winter frost.
Preventative Measures For Rose Pests Infestations
So, how can pest infestations be prevented in the future?
For many pests, all it takes is slight adjustments to your care routine.
Here are some cultural preventative measures:
Maintain healthy rose plants throughout the year.
Pests are more likely to infest a plant that is ill, as opposed to a strong plant.
Maintain a good care routine with your roses to keep pests and diseases at bay.
Some of these pests can be easily deterred by mulching around the base of your plants.
Mulch helps prevent ground-dwelling pests (such as slugs) from making their way toward your plant.
In addition, mulch also suppresses weeds, which is another big attractor for pests.
Keep a watchful eye out on your plants and perform weekly inspections for any signs of trouble.
Early detection is key in a lot of these scenarios.
Especially look on the undersides of leaves as well as the crooks of branches, where pests are likely to be hiding.
Biological Control:
Other gardeners utilize the natural predators of pests by encouraging them to come to their garden.
By planting early-blooming local flower spies, you can encourage predatory insects into your garden that will feed on these detrimental rose pests.
Examples of such insects include wasps and ladybugs.
Conclusion: Can You Control Rose Pests?
No one wants to wake up one morning and find that their beloved rose plants have fallen victim to a pest infestation. Luckily, there are several control methods that you can implement that will send pests away for good.
Knowledge is the main tool you need to stop rose pests, whether it be aphids, slugs, rose chafers, or any other type of rose pest.
Remember to always keep a close eye on your rose plants!
Early detection is everything when it comes to pest prevention.
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