Hello, some of my box woods trees are becoming yellow and branches are dying? They form a hedge around a garden with a juniper and a weeping mulberry tree in the middle. I have moved the mulch from around the trunks and have put coffee grounds on the soil to deter dogs from peeing on them (I think this is working).
What else can I do to save these trees? Should I cut off the dead branches of trim back the entire bush? Thank you for any guidance!
Boxwoods may suffer due to cold winter injury and salt damage, fungal diseases, pests, incorrect soil, poor drainage, poor nutrition, or periods of drought. Any one of these issues alone or in combination can be detrimental. Symptoms consist of weak and spindly plants. Dead or dying branches occur randomly in the bush. The older leaves drop prematurely and the remaining foliage develops a yellow color. Dead areas can develop along branches or near the crown.
Here are some suggestions to help restore your boxwoods.
As the spring progresses, check for new buds. Once they start developing, you can cut back any damaged or dead branches. You may want to thin the plants lightly to permit better air circulation.
Avoid pruning boxwoods on very hot days, and make sure to sterilize any shears or clippers used to prune or trim all garden plants by soaking in bleach: water solution (diluted 1:9) or rubbing alcohol for 10 seconds.
Water your boxwood well, particularly during drought periods. In the fall, make sure they get watered until the ground freezes. This is especially important in our South Central Ontario region where the ground can still be frozen on sunny days. When this happens the plant foliage starts to transpire but the roots cannot replace the lost moisture from the frozen soil, so the foliage dies of dehydration.
Enrich the soil around the plants with compost in the spring to add nutrition and improve the soil structure, thus allowing better water absorption. Do not overfertilize. Carefully clean up of any leaf debris from around the plant.
Avoid any salt around their roots. If the hedge is near a driveway, sidewalk or street that gets salted in winter, you may want to protect the plants from salt spray by placing burlap in front of them.
I hope these steps will help restore your hedge.