Leaves of affected stems progressively turn bronze, orange, dull green and straw-yellow, finally turning brown with defoliation leaving a gray skeleton of twigs. Providing optimum growing conditions is the best means of avoiding English boxwood decline. This includes prevention of moisture stress, removal of plant debris, and protection from winter injury. Lesion nematode is the most common and damaging nematode on boxwoods. These nematodes are widespread in North Carolina making nematode decline the most common disease on boxwoods.
Nematode damage can also occur as twig dieback, excessive leaf drop, or bronze foliage.
Currently, the only practical responses to boxwood nematode problems in the landscape are to lime soils to a pH of 7.0, fertilize, water regularly to avoid moisture stress, or replace boxwoods with a plant that is not susceptible to nematode injury. Boxwood Handbook, A Practical Guide to Knowing and Growing Boxwood . The American Boxwood Society, PO Box 85, Boyce, VA 22620. Boxwood Leafminer, Ornamental Insect Note 16. Boxwood Pest Management Calendar , Ornamental Insect Note 53.