As the seasons change and the trees lose their leaves, it’s time to prepare ourselves and our plants for the cold weather. It’s time to bring in the harvest and prune back the flower beds. If you live in a climate that’s prone to freezing, then you’ll need to get ready for the snow and ice. But if you have bamboo in your garden, what should you expect? And what can you do to keep your bamboo happier through the winter?
Bamboos, of the subfamily Bambusoideae, are perennial evergreens belonging to the grass family, Poaceae. As such, they will not die off in winter like an annual plant or drop their leaves in winter like a deciduous plant. Generally, most running bamboos are more cold-hardy and can easily survive prolonged freezes and temperatures well below 0º F. Most clumping bamboos, however, tend to be tropical or subtropical, and far more susceptible to frost damage. As winter approaches, it helps to insulate the roots of a bamboo plant with a layer of mulch.
Bamboo and winter evergreens
Unlike most broadleaf trees which will drop their leaves in the fall and go naked in the winter, bamboo plants are generally evergreen. It helps to be aware of this as you plan your garden, so you’ll know what to expect it to look like in winter. But there are a handful of exceptions, such as Arundinaria appalachiana, a temperate bamboo endemic to the Southeastern United States.
Normally it’s a good idea to mix deciduous and evergreen plants, so that you still have a fair distribution of greenery, even through the dead of winter.
When we think of evergreens, we usually think of coniferous trees, like pines and firs. Most other trees and shrubs tend to lose their leaves, especially in climates that typically see snow and ice. So bamboo is a great way to keep the garden looking lively as the other plants lose their foliage.
Boxwood, or Buxus, is another shrub whose small, rigid leaves keep their green throughout the winter. This evergreen quality is part of what makes bamboo and boxwood both such popular choices as hedges or privacy screens. There’s not much point in keeping a privacy screen that only provides privacy for about half of the year. And most conifers aren’t dense and compact enough to function as hedges, with the main exception of the yew.
Tropical vs Temperate Bamboo
Before you get too excited about planting all manner of evergreen bamboo in your New England garden, it’s important to know a few things about bamboo. While there are a wide variety of cold-hardy bamboos that can tolerate temperatures as low as 15 or 20 below zero Fahrenheit, many species of bamboo really prefer tropical or subtropical conditions.
These warm-weather bamboos are unlikely to survive an icy winter with several feet of snow. Or, if they do, there’s a good chance their leaves will fall and their culms will suffer some serious frost damage. Underground, in the robust rhizome network, is where bamboo is most likely to retain its life force.
So you’ll have to avoid the true tropical varieties, like those of the genus Dendrocalamus or Gigantochloa. But if temperatures rarely drop below 20º F, you can probably get away with growing certain subtropical varieties of Bambusa.
Most of the clumping bamboo species belong to these tropical and subtropical genera. However, there are a few genera of clumping bamboo that are extremely cold-hardy. Take a look at the genus Fargesia if it’s a clumping, cold-hardy, evergreen bamboo you’re looking for. They can commonly survive temperatures as low as negative 20º.
But if you’re in the market for a fast-spreading bamboo, or a runner, you’ll have no difficulty finding a variety that’s both evergreen and cold-tolerant. The genus Phyllostachys will offer the best selection, including a number of cold-hardy timber bamboos.
Check out our article on Cold-Hardy Bamboo for Snowy Climates for a more detailed listing of frost-friendly species.
When bamboos lose their leaves
An abnormally cold winter may cause some bamboo to lose its leaves, especially the subtropical varieties. If temperatures fall below the plant’s cold-hardiness, then you should expect to see some damage. In the unforgettable storm of February 2021, for example, many growers in Texas saw their resilient bamboo suffer unprecedented frost damage.
That damage usually involves the leaves falling off and some of the more tender culms dying back. But even if the whole plant appears to die, there’s often more than spark of life still glowing underground in the roots. It may take a year or two to recover and look good, but just cut out all the deadwood and give the bamboo some time to work its magic.
Ordinarily, bamboo loses its leaves in the spring. This may surprise or concern some gardeners, but it’s perfectly natural. Like most plants, bamboo produces fresh growth in the spring. But because it’s an evergreen, the new growth comes when the old leaves are still in place. So what happens is that the old leaves fall off to make room for the new ones. And as the old leaves gather on the ground, they provide a light layer of healthy, helpful mulch.
Brace your bamboo for the winter
Like most living things, bamboo does like to bundle up in the winter. The easiest and most effective way to protect your bamboo through the frosty months is with a fluffy layer of mulch.
Mulch can come in a variety of forms, but I generally rely on what’s available in the local area. If you live on acreage, you’ve probably got enough organic detritus to mulch your bamboo. Dried grass and dried leaves are helpful, but more substantial materials like bark and wood chips will provide greater insulation. And as the mulch breaks down, it will actually help to build up the topsoil with more humus.
A few inches of mulch is usually good for most bamboo. Smaller plants with thinner culms only need a couple of inches, otherwise, the new shoots will struggle to get through. Big timber bamboos can handle 5 or 6 inches of mulch without impeding their fresh growth.
If you found this article about bamboo’s winter habits useful and informative, feel free to share it with your friends. You might also appreciate some of our other in-depth articles on bamboo maintenance and cultivation.