While boxwood may not be one of my favorite plants, they are extremely useful in the landscape. And you can cut them for winter greenery. The reason they are the plant of the month is because of their winter durability. They provide quite a bit of green coming out of winter, and they look good in the snow too. Boxwoods come in many different varieties, which get varying sizes.
Besides being tough in the landscape, boxwood can take pruning quite well. This is actually one of the reasons I dislike them. While they can be pruned nicely into boxes, spheres, and other shapes, the smell of the cut leaves is displeasing to me and I prefer to let shrubs grow into their natural shape, and not shear them. Shearing, although it does not hurt them (unless you cut below the live green), causes them to be less hardy in winter and more susceptible to disease and insect attacks.
And even though there are some disease and insect problems with boxwood, there are enough disease tolerant varieties to make it the first plant of the month for 2024.
Boxwood Blight
This fungal disease was first found on boxwoods in North America in Connecticut in 2011. Since then, it has spread to several Canadian provinces and 30 states. The widespread nature of this blight is most likely caused by the over planting of boxwoods as hedges and in foundation plantings. As you know, I cannot stress enough about diversity in the landscape. And while I concede there is some necessity for massing of plants within the landscape; I do not recommend you choose just one species or cultivar from a genus.
This fungal disease mostly affects cultivars from the species level of Buxus sempervirens. It starts with fungal spores being moved by humans, tools, and animals primarily. Then, dark lesion are formed on the leaves and stems, resulting in leaf drop and death. There is no cure for the disease. But there is hope. Plant breeders have developed several new cultivars that are resistant to boxwood blight.
Disease Resistant Cultivars
The NewGen Series of boxwoods are resistant to the blight. Resistant means that they fight off the disease, though they may get some damage from it.
- NewGen Independence grows 3 to 4 feet tall and wide with a rounded shape and dark green color. It is hardy in Zones 5 to 8.
- NewGen Freedom grows 3 to 5 feet tall and wide. It may be a replacement for the popular Green Mountain which has a narrow, upright shape.
- Little Missy grows 3 feet tall and wide with lighter green leaves. It is hardy in Zones 5 to 9.
- NewGen Liberty Belle grows only 1 1/2 feet tall by 3 feet wide. It a is a perfect low growing boxwood like I have never seen before.
Other Problems with Boxwood
Besides blight, there are a few other problems worth noting about boxwoods. Deer and rabbits browse the stems and leaves in winter, especially in years of heavy snowfall, often chewing them down to the main trunk and killing them. Also in winters of extreme temperature swings, like sudden drops in temperature from warm to cold, the tips of early fall pruned plants may get frost damage. Frost damage looks like whitened lesions on the leaves, especially on new growth after pruning.
Box Tree Moth
The box tree moth is an invasive moth from East Asia which looks very similar to our native melonworm moth. The caterpillars of the box tree moth feed on the leaves of boxwood and can cause heavy defoliation and eventually death, if left unchecked. This is why it is important to get out into your landscape on a regular basis, daily or weekly. Or you can hire someone like me and my crews to take care of your landscape, if you live in Northeast Kansas! Box tree moth can be treated with any insecticide labeled for caterpillars.
For that, I prefer to use spinosad or Bt, being the safest for human use on caterpillars within the landscape. While my yard and garden are chemical free, I would treat for invasive pests on a case by case basis, and spot spraying only. Always read the label of the chemical before use, and check the plant for predators first!
Pruning Boxwood
There are 2 times a year when I recommend pruning or shearing boxwoods. If you really desire the ball or hedge look, then go ahead and do so to your boxwoods. Many people prefer that look. Shearing is best done in late spring or early summer here in the Central Great Plains. That is, either in May or June, before the heat and humidity take over. After shearing, the leaves are susceptible to scorch and heat stress, so if must shear, do so as early as possible.
You can also prune, not shear, in late fall, usually November with no damage to the plant. As long as the first hard freeze has happened, there is no danger of the plant sending out new growth and getting caught by a sudden temperature drop or freeze. But do not shear or prune in early fall, or you will have some winter damage as the plant responds to pruning by setting new growth.
Conclusion
Boxwood is a great shrub with a lot of uses. You can plant them singly or in hedges, or use them randomly within the landscape to provide color in the winter. Or plant them primarily for winter greenery, planning to prune them in late fall. They can be planted alongside many different kinds of plants, even other evergreens. Everything complements the boxwood.
Happy planting!
