Q: I have one Japanese boxwood out of six that has had sections die off. I trim out the dead parts hoping they will fill in. The rest of the bush looks healthy and I have seen no signs of this in the other five bushes. Any ideas on what I need to do?
A: It’s hard to determine a specific cause of branch die-back in boxwoods. The shrub sometimes gets a branch disease called volutella blight. The cure is to prune it out like you’ve done. The best defense against boxwood problems is to plant and care for them in the best way possible. Boxwoods ^hate^ waterlogged soil and ^detest^ dry soil. If your problem bush is growing in clay soil that was not amended well originally, that could be a cause of decline.
In my experience, Japanese boxwood, ^Buxus microphylla^ does much better than English boxwood, ^Buxus sempervirens^ in the South. Perhaps the best results come from ‘Green Mountain’ boxwood, a hybrid of the Japanese and English species. Try fertilizing your boxwoods with Milorganite or cottonseed meal. Both release nutrients very slowly, exactly as a boxwood likes.