Buxus sempervirens, or the box plant, grows as a bright green bush plant commonly used in topiary and other decorative landscaping designs. Buxus can grow nearly anywhere, in most types of soil, and both in sunlight and light shade. To produce healthy buxus plants that can withstand the heavy pruning of topiary work and keep up its green colour, you must provide adequate food plant food, also called fertiliser. Water-soluble liquid fertiliser, applied regularly, is extremely effective food for buxus.
Mix liquid plant fertiliser and water according to the specific product instructions. Use a balanced, all-purpose fertiliser; buxus does not require extra types of nutrients.
Spray the soil surrounding the buxus plants with the recommended amount of fertiliser every two weeks during the growing season, which is generally from early summer to early fall.
Apply the final dose of fertiliser before the first frost of the season. Do not fertilise the plant during the winter, since new growth will not be able to withstand cold weather. Begin the feeding regimen again after the final frost of the year in the spring.
Follow your fertiliser's specific instructions regarding rate of application and how often you need to reapply. These details will vary by the number of buxus plants you grow as well as the type and method of application. If you choose to use granular fertiliser, dig a small hole in the top layer of soil and add the recommended number of granules. These fertilisers must be reapplied, though at larger intervals, generally between three and 15 months. Fertiliser may encourage the buxus plant to develop small yellow flowers. If you use the buxus simply for its green foliage, trim away these flowers as soon as you see them. Otherwise they will draw nutrients and water from the leaves.
Do not apply more fertiliser than is recommended. Over-fertilising can discolour leaves and stunt growth.