azalea Leaf question
Hi, We have a azalea hedge in our yard and have been noticing that towards the end of the summer and now the fall, most of the leaves are turning a brownish color with black spots on them. Is this a disease or normal? We do use the holly tone some on the bush but not very much and do mulch it but otherwise, we do not do much to it. I have attached pictures. Thanks so much!
This looks like symptoms of lacebug damage, a sucking insect. Nymphs and adults suck chlorophyll from leaf tissue, causing a white stippling of leaves. Both stages eepost black excrement spots that stick to the bottom surface. Azaleas in full sun will be more susceptible to feeding damage. There are 4 generations a year in MD. Eggs ovewinter inserted in leaf tissue.
Feeding damage is mostly finished for the season. Next year, monitor infested plants for egg hatch and treat to control the nymphs. Beginning in late April and continuing throughout the summer look for white stippling that begins on older leaves. Turn stippled leaves over to find lacebug stage and black fecal spots. Treat with an application of a summer rate of horticutural oil. Thorough coverage is important including leaf undersides. Azaleas are best grown in partial shade.
Thanks so much! Would Neem oil work or is there a better one?
We recommend a summer rate of horticultural oil.