We're welcoming a bounty of boxwoods in the nursery this season, and we recently caught up with our plant experts for a crash course in Boxwood 101. Senior Plant Buyer Steve H. says, "While there are many, many varieties of boxwood (around 217 cultivars!), four groups are especially popular in North America: English, Korean, Japanese, and American. Boxwoods offer lots of diversity in mature size, habit and leaf appearance, so you can find options that are suitable for screening, hedging, container gardens, mixed plantings, and formal designs. Incredibly versatile, they’re adaptable to shearing, evergreen, able to grow in sun or shade, and generally deer-resistant. Boxwoods are also fairly easy to grow, thriving in well-drained, slightly acidic soils and offering a long life span with proper care." With new varieties (including the gorgeous greenery above!) arriving in our stores for spring, our experts shared their tips on thinking outside the boxwood.
Boxwood is man’s oldest garden ornamental, and was introduced to North America in the mid-seventeenth century. It was extremely popular in gardens during the early nineteenth century, and again during the Colonial Revival era. The first boxwood planting in America occurred around 1653 at Sylvester Manor on Shelter Island, New York. The garden featured boxwoods brought across the Atlantic from Amsterdam. Today, the largest collection of cultivars can be found at the Virginia State Arboretum.
Pruning: Boxwoods are very tolerant to pruning, which makes them ideal as hedges or even topiaries. Winter is the best time to trim your boxwoods using hand shears or electric clippers. Younger plants should be sheared more often; the best time to establish a shape is during the first few years. Frequent trimming encourages branching and new growth, which will create a denser, more defined shape over time. Avoid excessive pruning, which can make the branches too dense and prevent light from reaching the center of the plant. If you’d like to make a drastic change, prune in stages over several years.
Winter Care: Many boxwoods will remain evergreen throughout the winter, but some may develop brown leaves during the colder months. Don’t worry, the leaves will regain their color when spring arrives! For container gardens, make sure to plant your boxwood in a frostproof planter, or bring the entire container indoors or into the garage over winter. Avoid letting boxwoods rest under heavy snow, which can split the stems.
Fertilizer: Uniform yellowing of the lower foliage or leaf loss can be a sign of nitrogen deficiency, and indicates that fertilizer may be needed. A granular urea fertilizer with a 10-6-4 ratio is suitable in most cases, and should be applied in late fall for best results. We recommend using Dr. Earth Life, Dr. Earth Liquid All-Purpose, or NutriRoot for new plantings. Broadcast fertilizer around the base of the plant, just beyond the drip line, being careful to avoid direct contact with the roots. Surface application is best, while deep root fertilization should be avoided.
Pest Control: Common pests that may affect boxwoods include leafminers, mites, and psyllids. Nematodes and fungi are not a threat to most varieties. Check for insects in the spring, and treat as needed with EcoPM and EcoMite, or Azasol Systemic. If your garden is often damaged by deer, boxwoods make an excellent, deer-resistant planting.
Boxwoods can be used as individual specimens, container plantings, topiary, bonsai, hedges and screens, pairings, or groups in the landscape. Their compact-growing leaf structure makes them especially suited for pruning and shaping as a formal hedge. Many varieties offer a naturally rounded shape, which makes them well-suited to spherical pruning.
Container Gardens: American and English boxwoods are ideal for container gardens since they’re slow-growing, drought-tolerant, and need minimal fertilizer. For best growth, choose a fast-draining pot that is at least as wide and tall as the plant, and preferably bigger; the larger the container, the less you’ll need to repot or water. Fill the pot with compost to within ½” of the rim, leaving space so water won’t spill out. Make sure the soil is moist from top to bottom, watering around once a week during the hot summer months and significantly less in winter. Each spring, add about an inch of compost to the top of the pot.
Classics: European or Southern boxwood is a lush variety that can easily adapt to any pruned shape. Reaching up to 20’ tall, it grows rapidly in mild climates from Zones 6-8. In colder regions, it’s best planted in containers that can be overwintered in an interior space. A favorite at terrain, “Franklin’s Gem” is a small, hardy Korean boxwood that turns from glossy green to rich olive in winter. The variety takes its name from J. Franklin Styer—founder of the Pennsylvania nursery that’s now home to terrain at Styer’s. His son, Jacob, acquired a boxwood seedling from Korea around 1970 and introduced this remarkable plant to American gardeners.
Rounded: Varieties with a naturally rounded shape include “Green Mountain” and “Green Velvet.” Hardy and dense, “Green Mountain” can reach up to 5’ in height. With especially vivid foliage throughout the seasons, “Green Velvet” will grow at a moderate rate up to 4’ tall, making it ideal for border hedging.
Colorful: Variegated English boxwood offers dark green foliage with creamy, white marbling at the edge of each leaf. Growing up to 8’ tall and equally wide, it’s a show-stopping addition to the garden. “Green Beauty,” a Japanese variety, transforms from green to vibrant bronze during the colder months.
Dwarf: For smaller spaces or containers, “Dwarf English” boxwood will grow 1-2’ tall with tidy, compact green foliage. Another variety, “Wee Willie," is excellent for compact borders and requires minimal pruning.