All 6 of my plants have dead spots. It has been extremely hot and dry here. The middle of the plants at the base also have spider webs. I have started watering them, but wonder what else I should be doing for them. I have been told they do not get spider mites, but maybe they have something else that leaves webs. Should I cut off all the dead branches?
My Spirea Appear to Be Dying
Certified GKH Gardening Expert
Most likely it is a combination of heat/drought stress and a pest infestation, like spider mites--which do in fact affect these shrubs. Try upping the water and treat the plant with neem oil, which will take care of the pest and is a fungicide as well.
Do I have to wait for cooler temperatures before applying the neem oil? We have been in a heat wave. thankfully we are getting rain.