Ick! My roses are covered with aphids. How do I get rid of them?
Welcome to Spring anywhere in the world. Aphids are a tiny sucking insect that plague many plants in the Spring and Fall when the new growth is soft and ripe with delicious nutrients for them. While the variety of aphid that attack roses will not devastate the health of the plant they are certainly annoying and unsightly.
The information I will review in this piece is based on the best and most current science based information for the home gardener. You can access all the information you might ever need by researching on the Integrated Pest Management website hosted by UC Davis. (www.ipm.ucdavis.edu). Integrated Pest Management is a national program operated by major universities across the nation providing home and commercial gardeners with the best horticultural information gleaned from current science.
Aphids are typically tiny green or brown bugs that cluster together on rose buds. They are a perfect food for the good bugs in your garden. The larva and adult stage of lady bugs, green lacewing, soldier bugs and parasitic wasps love this Spring treat and will eat hundreds each day. Their leftovers look like little white rice grains left on the leaves of the plant. If you see this you will know that the beneficial insects are doing their best to intervene in your aphid outbreak.
BUT – maybe they aren’t working fast enough for you, still leaving too many live insects on your plants. You might have to get your hands dirty.
The first option is to wipe them off with your fingers. Just drag your clenched fingers upward over the infestation to remove the majority of the pests. That might gross you out but it is effective in controlling the pest. (Please wash your hands afterwards.) After wiping away most of the critters, spray the plants with a hard stream of water. Very few of these bugs have wings, so if they are dislodged from their banquet they can’t return easily and without constant food they die.
USE WATER?????? I know, I know. We are in a drought even after our rain fall. I’m not telling you to drown the area and flood the street. Short bursts will clean off the plant.
If you still have too many aphids for your liking, use an insecticidal soap spray. This product will desiccate the insect and the soap will help it slide of the plant when you spray the area with water. It takes a few days but it is effective in intervening in a severe outbreak. Use the product in a cool part of the day. Heat and sun can cause burning.
Last, but not least: Check your plants every few days for new infestations. Eggs are microscopic. Aphids reproduce rapidly and have many generations a year.
Check the IPM website for more detailed information.