Woody plants are plants that have hard stems (thus the term, "woody") and that have buds that survive above ground in winter. The best-known examples are trees and shrubs (bushes). These are commonly broken down further into the deciduous and evergreen categories.
The opposite of "woody plants" is "herbaceous" plants. The latter die back to the ground in cold climates during the winter. Their brown or tan stalks may remain standing, but they are lifeless. However, if they are perennial, their underground plant parts will live on, promising the plants' return, come spring.
Even though the trunks and branches of deciduous trees are very much alive during the winter, this does not always appear to be the case. The states of death and dormancy can seem similar in deciduous trees to the untrained eye. With all its leaves having fallen off in fall, how can you satisfy yourself that the tree is still alive? It is easier than you might think because it is color-coded! What I mean by that is that you can test a tree limb for life by making a small cut with a knife and looking for green. If you find some green (as opposed to finding only brown or tan), then you have established that the tree lives.
I Heard It Through the Grapevine: Some Vines Are Woody Plants
While trees and shrubs come to mind initially for most people when mention is made of woody plants, some vines also qualify. But while all trees and shrubs are, by definition, woody plants, not all vines are. For example, the following are examples of vines that are not (that is, they are herbaceous):
It tends to be the large climbing vines that are woody plants in the vine category.
Technically, woody vines are called "lianas," although you would be hard-pressed to find anybody in everyday life who uses that term. Here are some cold-hardy lianas with which I am familiar:
Another vine that is a woody plant is porcelain berry (Ampelopsis brevipedunculata), which appears in my picture. Like two of the vines listed above, it is an invasive plant in North America. It reaches 10-12 feet long and grows in planting zones 4-8. One reason why this plant has had such a successful career as an invader is that it thrives under a variety of conditions, ranging from full sun to partial shade.
Why might you wish to grow a woody vine in your landscaping rather than an herbaceous kind? Well, consider this scenario. You have a pergola, and you would like to grow a vine up and over it to furnish you with shade for the summer. An herbaceous vine would have to start from scratch in the spring; it might never make it all the way over the top of the pergola (especially if you garden in the North). But a woody vine such as wisteria has a head start: an established plant will have already achieved sufficient height through prior years' growth. This fact, along with its cold-hardiness and the beauty of its flowers, has made wisteria a favorite for covering pergolas.
Examples of Trees and Shrubs
As noted earlier, all trees and shrubs are woody plants, so there is no question here of exceptions. Most people are quite familiar with these two groups of plants in a general sense. But I take this opportunity to point to examples that I think are of particular interest (and with which the individual new to gardening and landscaping may not be familiar):
- Golden chain trees
- Hemlock trees (Learn how they differ from the hemlock associated with Socrates.)
- Hinoki cypress trees
- Japanese umbrella pine trees
- Pagoda dogwood trees
- Beautyberry shrubs
- Contorted hazelnut shrubs
- Bottlebrush shrubs (with flowers that smell like licorice)
- Flowering almond shrubs
- Kerria japonica AKA "Japanese rose shrubs" (Their light green bark furnishes winter landscape interest.)