How to Get Rid of Aphids on Roses

Why You Shouldn't Use Ordinary "Soapy Water" to Kill Aphids

Insecticidal soaps are sometimes used to control certain pests on roses (‌Rosa‌ spp.). These are relatively non-toxic natural soaps formulated for use on some plants.

Household detergents should never be used on plants, however. In some cases, it may be possible to reduce pest damage without resorting to chemical control at all.

What Are Insecticidal Soaps?

Insecticidal soaps are sold commercially in order to control pest infestations on a number of ornamental plants and crops, including roses. These soaps are less toxic than systemic insecticides and pesticides, do not leave a residue and are not harmful to wildlife or beneficial insects.

Insecticidal soap is effective against certain pests; it is not a blanket solution for any pest that might target a rose bush, so read the label carefully to make sure the product will work on the pest you have. Soap products work on many soft-bodied insects like aphids, soft scales, whiteflies, mealybugs, thrips and spider mites.

However, when using insecticidal soaps, it is nonetheless important to test the product on a small part of a leaf and wait a day to see if it causes any damage to the plant tissue.

Insecticidal soaps are mixed with water according to label instructions to create a soap solution. This solution must come into contact with pests in order to be effective.

Why Household Detergents Can Harm Your Roses

While insecticidal soaps are formulated for use on plants, household dishwashing and clothing detergents and other cleaning products are not. Using these detergents on roses or any other plant is not recommended for several reasons.

Household detergents contain chemicals that may strip plant leaves of the waxy cuticle that protects the leaves from pathogens and also prevents water loss. Therefore, if you wash rose bush leaves with soapy water, they are more likely to dry out through transpiration.

Dish soap and other household cleaners may also harm beneficial insects such as pollinators and other organisms.

Solutions to Rose Pest Problems

Roses can become infested with a number of garden pests, including aphids, which are soft-bodied insects that suck plant sap from the undersides of leaves. Spider mites, which are tiny arachnids, also feed by extracting sap from leaves. Japanese beetles and winged insects known as thrips are also pests of rose bushes.

Aphids on Roses Treatments

While there are many species of aphids, the rose aphid is the species most commonly found on rose plants. One way to control aphid populations is to apply insecticidal soaps about once a week. Because of how quickly these insects lay eggs and multiply, controlling aphids on rose bushes rather than eliminating them is often the goal.

Insecticidal soaps can also help rid rose leaves of sooty mold, which grows on a sweet substance called honeydew excreted by aphids.

It is also important to note that beneficial insects such as parasitic wasps, lacewings and ladybugs are natural enemies that prey on aphids, so using insecticidal soaps is preferable to harsher chemicals that can eliminate natural predators.

Insecticidal soaps can also be used to control thrips and spider mites.

Non-Chemical Pest Control

You can try to control an aphid infestation using non-chemical control methods, such as dislodging them with a stream of water from your garden hose.

Japanese beetles are one of several types of beetle that feed on rose flowers and flower buds, and sometimes on rose leaves. One way to control these pests is to manually pick them off a plant and drop them into soapy water rather than applying any chemical control to the leaves.