Mugo Pine "Mops" needles turning brown

Asked July 20, 2018, 9:08 AM EDT

I planted three Mugo pines about eight months ago. I noticed a few weeks ago that one of them had needles near the ground that were turning brown. Now a second one is showing the same symptoms. The rest of the plant look healthy and green, but the brown is spreading. I didn't see any insects, but don't know what to look for. Can you suggest what could be the problem and how to treat it?

Montgomery County Maryland shrubs abiotic issues

1 Response

We do not see any obvious signs of insect damage or disease. You mentioned that these shrubs were planted eight months ago. The symptom of dieback suggests a possible root problem. It could be poor establishment after transplanting. Were the plants root bound in their pots when you purchased them? Did you loosen the root ball and spread out the roots in the planting hole? Have you kept them watered regularly? Are these in a site that gets poor drainage? You could pull up one of the shrubs that is showing symptoms and check the roots. If the whole plant pulls out in the shape of the original container, that is a problem. The roots may not have struck out into the surrounding soil and can't take up sufficient water/nutrients. Healthy roots would look fleshy and white, not black or brown.
https://extension.umd.edu/hgic/trees-and-shrubs/planting-process

ckc