This dwarf-variety boxwood cultivar was introduced in 1982 at a nursery in New Jersey. It was selected especially for its cold weather hardiness, ultra-shiny dark green leaves, and lime green new growth. New growth can be encouraged with yearly pruning in the spring. The foliage will seem to grow thicker whenever it is pruned. ‘Winter Gem’ shines brightest when used formally in straight lines, as patterns as a hedge, or when shaped in a ball or square. It can also, however, hold its own in a landscape without trimming, and its compact growth habit makes it an ideal choice for landscapes with limited space. If you are shopping for Winter Gem Boxwood and cannot find a plant named Buxus sinica var. insularis ‘Winter Gem’, do not worry. In commerce, the shrubs are usually sold under the synonyms Buxus microphylla var. japonica ‘Winter Gem’ or Buxus microphylla var. koreana ‘Winter Gem.’ Achieving a low privacy or border hedge with Winter Gem boxwoods can be done by spacing the shrub 12-24 inches apart when planting.
Light
‘Winter Gem’ Boxwood grows well in a wide range of light conditions, from full sun to partial shade.
Soil
The shrub will do okay in any soil that is not consistently wet. It prefers medium moisture in a well-drained soil that is sandy or loamy and with a neutral pH.
Water
Ensuring a newly planted Winter Gem boxwood receives one inch of water per week is essential until the plant is established. Minimal supplemental watering is necessary for established boxwood. The ‘Winter Gem’ is somewhat drought-tolerant but not for extended periods. Mulching the beds under the shrubs is vital for moisture retention to guard the very shallow root system.
Temperature and Humidity
The ‘Winter Gem’ cultivar is ideal for people who have tried this species in areas where it suffers from burnt foliage due to frosty temperatures. The shrub is hardy down to temperatures as low as -20o Fahrenheit. The perfect range for this shrub is anywhere in USDA Zones 5-9. In zone 5, plant ‘Winter Gem’ where it receives some protection from harsh winter winds.
Fertilizer
Every spring ‘Winter Gem’ will benefit from a shot of fertilizer. A suitable fertilizer for boxwood is a 10-6-4 mix, but it should only be applied if the beds under the shrub have been mulched. Applying fertilizer directly to the soil can harm the boxwood’s shallow roots.
Pruning
The ‘Winter Gem’ boxwood will reach a height of two to three feet tall and have a spread of two to three feet naturally. Trim stray growth for a more formal look. In colder climates pruning any boxwood should only be done in spring, never fall or winter. This will help achieve dense, compact growth. .
