full sun, part sun
Bloom Period and Seasonal Color
Blooms in spring are not significant. Mostly grown for its evergreen foliage
Mature Height x Spread
4 to 15 feet x 4 to 15 feet
Boxwood is a standard evergreen shrub that is often used in formal gardens throughout England and Europe. We certainly can grow boxwoods in New England, too. It’s best grown in a formal hedge to define a space or used to create a knot garden. It’s also a good shrub for foundation plantings and to mix in a perennial flower border to add a green backdrop for other flowers. The broad, evergreen leaves can be sheared multiple times during the growing season to create a formal look or the plant can be pruned more informally to have a more natural appearance. If not pruned regularly, though, it can become large and will need drastic pruning to bring it back into shape.
When, Where and How to Plant
Boxwood is hardy to zone 5, so in colder parts of New England it may need winter protection to survive. Purchase boxwood plants from a local garden center. Plant from spring to summer in full to part sun in well drained, compost amended soil. Boxwood will not grow well on poorly drained soils. Space plants 2 to 6 feet apart.
Boxwood grows best in cool, moist, fertile soils. Water regularly and mulch with bark mulch to keep the soil evenly moist and keep weeds at bay. Be careful weeding since boxwoods have shallow root systems. Fertilize in spring with a layer of compost and a handful of an organic fertilizer.
Regional Advice and Care
Boxwood can be marginally hardy in our region and the evergreen leaves can turn bronze if exposed to winter winds and cold. Choose winter hardy varieties, plant them in a protected spot away from winter winds, and protect the evergreen leaves by wrapping burlap around four stakes placed around the plant so the burlap doesn’t touch the boxwood foliage. Shear boxwoods regularly starting in early summer to keep them in shape. Boxwoods also make good topiary shrubs, pruned into geometric shapes. If they get overgrown, they can be severely pruned and will regrow.
Companion Planting and Design
Plant boxwood shrubs in a low hedge to outline a formal herb or flower garden, as a specimen plant in a border, or along the house foundation. Boxwood creates a green backdrop for colorful perennial flowers, such as salvia, black-eyed Susan and veronica, and annual flowers, such as zinnias, cosmos and cleome. Mix and match flowering shrubs, such as potentilla and dwarf spirea, with boxwoods.
The Korean boxwood (B. microphylla) are consider the most cold hardy. The hybrids, ‘Green Gem’ and ‘Green Velvet’, grow 3 feet tall and wide in a rounded form. ‘Winter Beauty’ has dark green foliage in a 4 foot tall and wide, rounded form. ‘Green Mountain’ can grow to 6 feet tall and wide with good cold hardiness.
Excerpted from my book, New England Getting Started Garden Guide.