First, the spray of the salt water on the foliage can cause the plant to desiccate in those tissues, killing the leaves on one side of the plant.

Salt used for sidewalks and roadways can cause damage to boxwoods. Photo by Jan Byrne, MSU Plant & Pest Diagnostics. Winter damage of boxwoods on the outermost growth and growth that was above the snowline. As long as the damage is not overly severe, growers can just prune out or prune off the damaged foliage. Winter damage is especially distinctive in that the growth below the former snowline is still green. Plants are especially susceptible to winter damage in temperatures below -10 degrees Fahrenheit, especially in locations next to pavement or siding of the house with direct sunlight that warms the tissue up too quickly. Buxus sempervirens is typically hardy down to USDA Zone 5. It becomes apparent as the snow recedes and the uppermost or outermost leaves and stems on the boxwoods are brown. Winter injury is the most common problem that affects boxwood. Here are seven common aliments of boxwood plants. However, there are numerous reasons for defoliation and browning of boxwood plants. For pictures of these symptoms, see “ Preventing the spread of boxwood blight in landscapes.” If the weather is humid, the underside of the leaf will have a white, frosty appearance caused by the formation of upright bundles of fungal spores. These can occur on the stem from the soil line to the shoot tips. Black, elongated, streaking lesions may also be visible on the stem. These spots eventually grow larger and coalesce before turning brown or straw-like and dropping to the ground. Initial symptoms are generally first observed in late spring or early summer when close examination of boxwood leaves may reveal round, dark or light brown leaf spots with darker borders and potentially a yellow halo.

Generally, part of the plant will become chlorotic or brown, and leaves will rapidly fall to the ground, leaving bare branches behind. In boxwood, often the first symptom noticed is a large amount of rapid defoliation (leaf drop), which is indicative of a severe infection. Boxwood blight ( Calonectria pseudonaviculata) is a fungal pathogen of species in the plant family Buxaceae, which includes the popular boxwood, sweetbox and Pachysandra spp. It is a legitimate concern because the disease has been found in Michigan and 27 other states. Since boxwood blight has been found in Michigan for the first time in summer of 2018, growers, landscapers and consumers alike are concerned that their boxwoods could have boxwood blight.

Death spiral black on side completely