I planted these shrubs about four years ago. They haven’t grown much, if at all. For two years now, they have looked like half of each bush is dying. It hasn’t gotten any worse, but I’m not sure what to do. Any advice would be greatly appreciated.
The Gardener’s Answer
Thanks for sending the pictures. They were helpful. There is definitely significant damage to your boxwoods. It is suspicious that the damage seems to be in the same location on both evergreens.
From the pictures, it appears that the rest of the plants are healthy. I suspect the die-back has to do with an herbicide drift. It could be some winter damage too because of the exposure, but we can rule out insect activity since it would be more evident throughout the plant. Stressed plants are more susceptible to insect damage so there may be some secondary issues.
Has this bed or nearby lawn been sprayed with any weed killer since you planted your boxwoods? Most of these products contain glyphosate as the active ingredient; it will kill all green growth that it comes into contact with. Although it was not intentionally sprayed on the boxwoods, a wind gust could easily carry this liquid spray and have killed that part of your plants.
Typically when evergreens die back they do not put on new growth to replace the lost. Boxwoods are tough, and it is helpful that these are settled and otherwise healthy plants. A light dose of fertilizer may help, but do not overdo it because too much food can have the reverse affect. If they do not put on any new growth in the next month or so, you might consider replacing them.