From: Fine Gardening
Since the first confirmed case in the United States about a year ago, boxwood blight (caused by Cylindrocladium pseudonaviculatum) has spread to 10 states and two Canadian provinces. All of the commercial boxwoods (Buxus spp. and cvs., USDA Hardiness Zones 6–9) that researchers have tested are vulnerable, as well as other plants in the boxwood family, including pachysandra (Pachysandra spp. and cvs., Zones 4–9) and sweet box (Sarcococca spp. and cvs., Zones 6–9). Although this fungal disease doesn’t typically kill its host plant, it does have a serious impact on the plant’s appearance-often stripping the shrub of its leaves completely. Although the roots remain healthy, infected boxwood looks dead, thanks to its bare branches. With still no cure in sight, the home gardener’s best line of defense is prevention. As you’re buying boxwood this fall, be sure to carefully inspect each plant before making a purchase, and don’t ignore the disease’s early symptoms if you spot them in your garden.