Evergreens are something of a misnomer, as the color in question need not be green. For instance, the color may be blue or gold.
What Are Evergreens?
The term "evergreen" means having foliage that persists (as opposed to dropping from the tree) and retains its color throughout the year, rather than changing color according to the seasons. Blue spruces and white firs are examples of evergreens.
Examples of evergreens with golden foliage are:
- Colorado blue spruce trees (Picea pungens): The color that these evergreens retain throughout the year is a silvery blue.
- Blue Star juniper (Juniperus squamata 'Blue Star'): Its silvery-blue needle clusters remind you of stars (thus the common name).
There are also plants with golden foliage that keep that color year round, such as:
- Vintage Gold false cypress (Chamaecyparis pisifera 'Vintage Gold'): This mounding evergreen shrub (5 feet x 3 feet) sports golden, thread-like leaves.
- Cripps false cypress (Chamaecyparis obtusa 'Crippsii'): A good choice if you want a golden evergreen in tree form (10 feet x 5 feet).
Differences Between Evergreens, Conifers, Deciduous Plants
Trees and shrubs can be classified as either evergreen or deciduous (the latter drop their leaves in fall). Another term that comes into play here is "conifer," which literally means "bearing cones." Many conifer trees are evergreen, but not all are, so the two words are not synonymous, even though some people mistakenly use them that way. The tamarack, or "larch" tree (Larix laricina), for example, is a conifer, but it is not an evergreen.
Yet another distinction is between the needled evergreens and broadleaf evergreens. The latter are represented by such plants as Sky Pencil holly (Ilex japonica 'Sky Pencil') and most other holly shrubs (but not winterberry holly (Ilex verticillata), which loses its leaves in fall and is therefore classified as deciduous). The meaning of "broadleaf" is easy to remember because it is a highly descriptive term: Broadleaf plants have leaves with a flat, relatively broad surface.
Non-botanists are far more likely to think of the needle-bearers than of the broadleaf group when they hear mention of "evergreens." Examples include:
- Mugo pine tree (Pinus mugo)
- Canadian hemlock tree (Tsuga canadiensis)
- Yew shrubs (Taxus spp.)
- Dwarf Alberta spruce (Picea glauca 'Conica')
- Blue Rug juniper (Juniperus horizontalis 'Wiltonii')
- Emerald Green arborvitae (Thuja occidentalis 'Emerald Green')
- Hinoki cypress (Chamaecyparis obtusa 'Gracilis')
- Eastern white pine trees (Pinus strobus)
Evergreens Range From Tall Pines to Short Perennials
Those who have never paid much attention to plant identification sometimes erroneously treat "pine" and "evergreen" as if they were synonyms. Pines are, indeed, evergreens, but they comprise only one group under the "evergreen" umbrella.
Nor does the foliage of all evergreen trees and shrubs look alike. If you take a close look at the needles of Canadian hemlock trees or yew shrubs, for example, you will see that they are short and flat. They are very much unlike the needles of eastern white pine trees or mugo pine trees. Still other needled evergreens have needles that are awl-like, scale-like, or blade-like.
Not all evergreens are large plants, either. There are even some short perennials that are evergreen. Perennials that are not evergreen are called "herbaceous" rather than "deciduous." The warmer the winters in a region, the more evergreen perennials there will be, generally speaking. But even in chilly USDA planting zone 5 there are some evergreen perennials, including:
Uses for Evergreen Trees and Shrubs
But most people, when casually referring to "evergreens," really mean shrubs and trees that bear persistent leaves, which retain their color throughout the year. These are, indeed, some of the most valued plants in the landscape because the fact that they hold onto their leaves year-round allows you to do things with them in your landscaping that you cannot do with deciduous shrubs and trees. For example:
- If you wish to grow a hedge to form a "living wall" for privacy, evergreens will give you that privacy year round.
- Winter landscaping is a challenge in northern climes. Northerners seeking year-round color in the yard rely on evergreens to furnish color in the winter yard.
A Botanical Name Indicating Evergreen Status
Some plants give you a clue as to their evergreen status right in their botanical names. Look for the term, sempervirens, which is composed of two Latin words: semper, meaning "always," plus "virens," which means "green." Examples are:
- Iberis sempervirens (candytuft, a perennial)
- Helictotrichon sempervirens (blue oat grass, an ornamental grass)
- Lonicera sempervirens (honeysuckle, a vine)
- Buxus sempervirens (English boxwood, a shrub)