Dear Miss Floribunda,
I empathize with the person who wrote to you last month asking for suggestions for a hedge, and, at first, I liked your proposal of arborvitae. However, my backyard is small, so I wonder if you know of shrubs of more manageable size. I certainly don’t want anything so tall that if it fell over my house might be hit! I’d like a height of maybe 10 feet, although 8 feet would be OK, and though I want a hedge thick enough to give privacy, I’d hope it wouldn’t be bushy enough to invade my neighbor’s space. Any ideas?
Terrified of Tumbling Timber on Madison Street
Although this would entail a little labor, the American arborvitae (Thuya occidentalis) recommended last month can be trimmed into a fairly low hedge. It is quite dense, however, and does take up space extending well beyond a property line — as do the other shrubs suggested.
I assume you prefer an evergreen for a year-round curtain of foliage. I asked my mentor from the National Arboretum, Dr. Betula Bower, for recommendations. She informed me that there is a variety of arborvitae called Forever Goldy that reaches no higher than 12 feet. As the name suggests, it is not a deep green but a near-yellow chartreuse. This is a color most people love or hate. The Emerald Petite variety, a truer green, grows only 6 feet high — which may be lower than you like.
I then asked Dr. Bower about the English, or cherry, laurel (Prunus laurocerasus). I had recently admired a hedge of it on a visit to a friend, Peter LePeintre, who lives in a row house in Washington, D.C. Peter’s postage-stamp backyard faces an alley whose dinginess is effectively blocked out by a slim but dense hedge only 10 feet tall. He told me it could reach as high as 40 feet, but he trims it each year to keep it this height. It is easy to prune, and he finds the almond fragrance from the trimmings delicious.
Dr. Bower, however, had some warnings. The English laurel actually comes from a region extending from Albania through Turkey and Iran to the Caucasus Mountains. She advised against it because it can be quite invasive. It is a very fast grower, at 1 to 2 feet a year. Its fruit is poisonous, except to the birds that spread it far and wide. In addition, its root system is invasive and crowds out other plants near it.
She suggested in its stead the Carolina cherry laurel (Prunus caroliniana). Like the alien English laurel, it is a fast grower at 25 inches a year, but its root system is not invasive. Also, its leaves are fragrant, and the beautiful clusters of white flowers that bloom in late winter and very early spring actually smell like maraschino cherries.
The Carolina cherry laurel’s early developing berries are an important food source for birds, including quail, wild turkey and song birds, at a time of year when there is little else for them to eat. However, as with the alien English laurel, the seeds of its small and untempting black fruit contain some cyanide and are poisonous to humans and some other mammals — including deer, which avoid it. Other mammals, including raccoons, eat its fruit with impunity. Although it could potentially poison dogs and cats, they are highly unlikely to graze on it.
The nectar of the Carolina cherry laurel’s flowers is a magnet to bees and many butterflies. It is an important host plant for the Eastern tiger swallowtail, the red-spotted purple, the hairstreak, the viceroy, and various spring and summer azures. It thrives in the acid soil of our area, is tolerant of sun or shade, and survives our winters.
Peter also told me of a similarly “manageable” hedge that didn’t need any pruning at all, taking me to see another neighbor who had a hedge of Sky Pencil holly trees (Ilex crenata). It was only 10 feet tall and only 2 feet wide. I was pleased to see that the evergreen leaves of this holly are not as prickly as those of most hollies. I was told that in fall it produces berries of a subdued purple rather than a festive red, but the owner liked them because they blend with the color scheme of her particular decor.
Regarding the Sky Pencil holly, Dr. Bower told me it comes from Japan, and while its root system is not invasive, birds will eat and distribute its berries. It is not easy to grow, however, because it does not like our heavy clay soil nor our harsh afternoon sun. Considerable soil amendment would be needed for it to survive, and you should avoid planting it on the west side of your house. On the plus side, it is pollinated by bees, and so, unlike most alien species, it does support some pollinators. It is a reasonably fast grower at 9 inches a year.
Please check the website of the Hyattsville Horticultural Society, hyattsvillehorticulture.org, for information about when the next meeting will take place.