Do shrubs with shedding spotted foliage need water or insecticide?

Asked July 19, 2018, 3:55 PM EDT

Hi, We have a set of shurbs in the front of our home that were recently trimmed. They are now shedding leaves. The leaves left on the shrubs have brown spots and do not look healthy. The branches of the shrubs still look green and the trunks are not rotting. There do not appear to be any holes around the shrubs indicating vole activity. Do we need to increase watering frequency? Or do we need to spray these shrubs for insects? Thank you!

Montgomery County Maryland shrubs abiotic issues pest insects and mites

1 Response

On the remaining leaves of your shrub, it looks like there is evidence of spider mite damage. That said, there is not much left for them to feed on at this point, so we do not recommend using any insecticide. The best thing you can do would be to keep the plants watered regularly when we do not have rain -- and give them time to recover. If there are no root or stem problems, they will recover with time.

For the future, you may want to read about spider mites and what to look for. See the information on our website at the link below. Using insecticides too often can actually exacerbate spider mite problems because their natural predators also get knocked down. Horticultural oil is effective for treating spider mites and it is gentler on beneficial insects. https://extension.umd.edu/hgic/spider-mites-trees-and-shrubs

ckc