You’re probably familiar with two basic types of trees: deciduous trees and evergreen trees. Deciduous trees drop all of their leaves every year as the weather grows cold or during a dry season. In some of these trees, such as oaks and maples, the leaves change into brilliant colors before they drop. The leaves of evergreen trees and shrubs are green all year, even during the most brutal winters. Here are some things you may not know about evergreens.
Why Are They Evergreen?
Scientists believe that plants tend to be evergreen in climates where it’s always fairly warm and wet and food is abundant, such as in a tropical rainforest. Losing leaves all at once is the way a tree saves energy during the winter or during a drought or dry season. Evergreen trees in cold climates tend to be conifers because needles can stand severe cold better than broadleaf trees. Evergreen conifers are also more likely to grow in poor soils, as holding on to their needles helps them hold on to nutrients.
Not All Evergreens Are Conifers and Vice Versa
Conifers are trees such as:
- Spruce
- Fir
- Pines
- Yews
- Cedars
These evergreens are called conifers because they produce cones, which contain their seeds. In lumber terminology, they’re called softwoods, even though their wood is not necessarily soft; it is just less dense than the wood of trees such as oaks and maples.
However, not all conifers are evergreens. The larch, for example, is a conifer that is not an evergreen. In the fall its needles turn from green to gold and then fall all at once, like other deciduous trees.
On the other hand, not all evergreens are conifers. Holly trees, southern magnolias, and live oaks are not conifers but are still evergreen trees.
Evergreens Do Drop Their Leaves
Evergreens do drop their leaves or needles, but they don’t do so all at once the way deciduous trees do. Their leaves can hang on the tree for years before they drop. The needles of the bristlecone pine can last for more than 30 years, which isn’t surprising for a tree than can live for 4,000 years.
Broadleaf Evergreens Have Thick Leaves
The leaves of broadleaf evergreens are thicker than those of broadleaf deciduous trees. You can see this if you contrast the leaves of a holly tree, live oak, or southern magnolia with those of a maple or oak tree. The leaves of the first three trees are almost leathery.
Evergreens Keep Down Energy Costs
Planting evergreens around your home can cut down on your energy bills. Their foliage can keep your house cooler in the summer by blocking the heat from the sun. They can also protect your house from wind and absorb sounds, which is a boon if you live in a city.
Call Us for More Information
With relatively warm temperatures year-round, Knoxville is the perfect place for a variety of evergreens. If you have an evergreen tree or shrub on your property and need help with trimming and pruning or other care, don’t hesitate to get in touch with our arborists at Shelton’s Tree Service.
