Winter gem boxwood plants thrive in full to partial sunlight in hardiness zones 5 to 9. Consistent sunlight is necessary even when there is a lack of rainfall. It is important to water the plant regularly during the first growing season, as this allows it to establish a healthy and expansive root system. Winter gem boxwood requires well-draining soil with a pH between 6.5 and 7.5.
If the plant's lower leaves turn yellow, it is necessary to apply fertilizer to compensate for a lack of nitrogen. A granular urea fertilizer with a 10-6-4 ratio is ideal. Before applying fertilizer to the plant's base, the soil should be mulched and moistened. To prevent root burn, the fertilizer should never come into contact with the plant's roots.
If the plant is infested with pests like moths, beetles, fly larvae, psyllids or other common insects, spinosad or neem oil should be applied. Falling or discolored leaves are a sign of infestation. Applying organic mulch during the fall can help keep the plant healthy in colder temperatures. Shredded hardwood bark can be used to increase the soil's pH level. During the summer, the plant should be monitored for weeds and additional water should be given as needed. Winter is an ideal time for pruning the boxwood.