Add boxwood to a proper English garden

Everyone loves an English garden, but there are many types and they are all very different.

An English cottage garden is informal and filled with many plants, all seemingly crowded into every available space. The English landscape garden is a vast, park-like setting with large lawns and groves of trees and shrubs and the formal English garden is made up of geometric bed designs. Seldom do we see a formal English garden without the familiar dwarf boxwood hedge surrounding beds containing well manicured plants, all keeping to their own space.

I keep my gardens rather informal, but that doesn’t stop me from loving boxwood. Common boxwood grows best in zones 6 to 8, but winter hardy varieties can survive in our zone 5 climate. In our area boxwood shrubs should be protected and lightly mulched. I have toured northern gardens as well as a few in Canada, including the Royal Botanical Gardens in Burlington, Ontario, and have seen boxwood growing all along the way.

Buxus sempervirens are broad-leaf shrubs with tightly compact, light to medium-green leaves. Commonly called American boxwood, this shrub can grow as tall as 15 to 20 feet. Buxus sempervirens ‘Suffruticosa’, commonly called English boxwood, is a smaller, slow growing variety. There are also varieties called Japanese or Korean boxwood, all with various characteristics. But don’t be fooled when purchasing a shrub at a garden center. Many species can be labeled as ”English,” even if they are of a different species.

According to the American Boxwood Society, there are more than 140 different cultivars of the shrub, all varying in size and shape, leaf characteristics and hardiness, but its the dwarf varieties that seem to attract the most attention. Probably because they make small, cute hedges to surround a garden bed, transforming a casual setting into something more formal.

My favorite is a cultivar called ‘Winter Gem,’ a form of Buxus microphylla (native to Japan). In botanical-talk, microphylla translates to ”little leaf.” The leaves are small and round, making this a perfect plant for a miniature garden and as bonsai specimens.

First brought to this country in the 1600s from Amsterdam, boxwood became popular in colonial gardens in Williamsburg, Va., and at the White House. The microphylla cultivars are slow growers, usually reaching not more than two to four feet tall when mature, but are easily pruned into any size or shape desired. They are perfect for the smaller hedge borders and formal shaping as topiaries. Winter Gem is a cold-hardy variety that survives our zone 5 climate.

It is a low maintenance plant, as well, although keeping it watered throughout the growing season can help protect it better during the colder months. The roots are shallow and good drainage is a must to avoid root rot. Boxwood doesn’t like to sit in standing water.

Although this shrub grows well in both sunshine and partial shade, the leaves will turn a bronze-yellow color if the sun is too bright and hot or if it has too much exposure to drying winter winds. When the weather improves in spring, it doesn’t take long for the new green growth to take over and damaged leaves can easily be trimmed away. To avoid this color change, however, giving the plants a little shade from a nearby tree or creating a temporary windbreak from winter winds can help. There are also anti-dessicant sprays available.

Plant dessication occurs when the frozen ground causes a plant to be deprived of water and exposure to sun and wind compounds the dry conditions. This problem can affect other plants as well.

In May and early June, an insect called psyllid can attack boxwood leaves, causing them to curl and stunt their growth. Spraying with horticultural oil or insecticidal soap as soon as the insects appear in the spring can help keep them under control. Although the insects can make the plants look unsightly, they won’t damage the plant in the long term.