Boxwood Leafminer

Asked September 19, 2016, 9:28 PM EDT

Hi, I just discovered what appear to be boxwood leafminer larvae in all of my boxwoods. I can't seem to find any info online as to what to do if discovered in the fall. Do I prune away the effected areas (which seems to be all the new growth), do I spray a pesticide, or do I do nothing until Spring? Thanks! Erika Peter

Campbell County Kentucky

3 Responses

The boxwood leafminer is a major best of boxwood. The adult insect emerges in spring. One way to irritate its life-cycle is to prune the new growth. This is a good time to prune or early spring prior to new foliage growth and (late March early April) prior to adult activity. see the link below for more information:
https://www.ces.ncsu.edu/depts/ent/notes/O&T/shrubs/ort016e/ort016e.htm
Let me know if you have any further questions.

Thank you for your response! So I should prune all the growth now that appears to be infested? Would you recommend a pesticide to prevent them next year?

Also, while I'm asking questions, I have 3 hydrangeas on my property that never bloom. One is an endless summer variety that I've had for 3 years and they other 2 are oakleaf that I planted in the sping. Do you know why they might not be blooming?

Thanks!

Good afternoon,

Boxwood like most woody shrubs can be pruned in late fall (after frost). if you prune too soon, the foliage will not have time to heal and can show signs of damage. Or late winter prior to spring growth.
Hydrangeas are a bit tricky. Endless summer varieties are pH sensitive. Most varieties prefer shade and well drained soil. Oak leaf, is a native and can tolerate of our clay, akaline soils. Here's more information on hydrangeas:
http://www.clemson.edu/extension/hgic/plants/landscape/shrubs/hgic1067.html