By Stan V. Griep
American Rose Society Consulting Master Rosarian – Rocky Mountain District
Aphids like to visit our plants and rose bushes every year and can form a major attack on them fairly quickly. The aphids that attack rose bushes are usually either Macrosiphum rosae (Rose aphid) or Macrosiphum euphorbiae (Potato aphid), which attacks many other flowering plants as well. Controlling aphids on roses is well worth the effort to keep beautiful roses.
How to Get Rid of Aphids on Roses
In light cases, aphids on roses can be picked off by hand and squished or sometimes a quick tapping of the bloom or foliage will knock them to the ground. Once on the ground, they will be easier prey for the garden good guy insects.
Also in the lighter cases of aphids on rose bushes, I have had some success with the strong water spray method. Using a hose end water sprayer, spray the foliage and blooms down well. The spray of water will need to be fairly strong so as to knock the aphids off but not so strong that it defoliates the rose bush or plant – nor would one want to damage the blooms with too hard a water spray. This may need to be continued for several days to keep the aphids off the plants and/or bushes.
Aphids are big nitrogen feeders, thus another way to help control aphids on roses is to use slow or time- release (urea based) nitrogen fertilizers. Caring for roses with aphids like this means there is not a big push of nitrogen to the plants or bushes right after feeding them, which the aphids find most attractive for their reproduction. Most organic fertilizers will fit into the time-release category.
Lady beetles or ladybugs, their larvae in particular, and green lacewings and their larvae is another way how to get rid of aphids on roses; however, they can take some time to gain control. If under a significant attack, this method will likely not give the desired results quickly enough.
The last straw option, as I call it, is to break out an insecticide and spray the rose bushes and/or plants. Here is a listing of some of the insecticides I have used with good results at gaining control:
(This listing is alphabetical and not in order of preference.)
- Acephate (Orethene) – has systemic activity, thus it will move through the foliage of the plant and reach those aphids that are hidden within and beneath the foliage.
- Fertilome Rose Spray – This product contains Diazinon and Daconil to control both sucking and chewing insects.
- Merit® 75W – a higher initial cost option but very effective. The recommended application rate for rose bushes is one teaspoon per 10 gallons applied every other week, thus a little goes a long way.
- Ortho® Rose Pride® Insect Killer
- Safer Insecticidal Soap
Be aware, most of these last straw insecticide options will kill the garden good guy insects as well and have the potential of opening up your rose bushes and plants to attack from other harmful insects later on.