|I have what I believe to be aphids on my viburnums. Also some of my other plants (Ty, robilini) have a white powdery residue. What is the best way to control whats going on. It is in the back of the house where it has been quite windy. I do water by hand on days the sprinker doesn't come on. Thank you for your help.
|Insecticidal soap works well against aphids. These little pests give birth to live young so you can have several generations feeding all at the same time. You'll need to repeat the treatment every 2-3 days until you've gotten them all. Be sure to spray on the undersides of the leaves.
The white powdery substance is probably a fungal disease called powdery mildew. It is common in spring and fall when daytime temperatures are warm and nights are cool. Pick off the infected leaves and use a garden fungicide to protect the rest of the plant.
Best wishes with your landscape!