Evergreens are a wonderful way to bring year-round interest and structure to your gardens and borders, and with the introduction of new dwarf varieties, there is renewed interest in adding them into the landscape as specimen plants. Several species of evergreens are also extremely popular as hedging plants, as their narrow, columnar form and year-round foliage, are ideal for tight spaces.
Unfortunately, because of their growing popularity and perhaps over-hyped easy-care qualities, I’m seeing lots of evergreens that are suffering from neglect and disease. Sadly, once these trees become significantly damaged, they aren’t likely to recover and must be replaced. I’m always sad to see arborvitae hedges where half the trees are dead or dying or an Alberta Spruce that is clearly suffering from a spider mite infestation. These are beautiful plants that are expensive to replace, so it’s important to understand how to care for evergreen trees and shrubs so that they look their best for years.
Right Plant, Right Place
Properly siting an evergreen tree or shrub is the first step in preventing disease or damage. Because most can suffer from wind damage or sun scald, especially in climates with long and snowy winters, it’s important to avoid placing your evergreens where they are fully exposed to sun and drying winds. Ask your local garden center about varieties that are more wind resistant, or consider protecting them with a wind-breaking fence. Since improperly wrapping trees and shrubs can actually damage your plants, you should consult with a licensed Arborist or horticulturist before you go about buying tree wrap or burlap.
Overly wet or clay soils can be challenging for many plants, including evergreen trees and shrubs. There are some varieties, like Atlantic White Cedar, that do well in wet soils, but as a general rule if your soil stays wet or mushy for more than a day, you may need to build a berm or stick with containerized evergreens.
Water, Water, Water
While most evergreens require very little pruning if left to grow in their natural form, they do need frequent watering, especially in the first year they are planted. If not properly watered, evergreens will be more likely to suffer from winter burn or sun scald. Be sure your evergreens are getting at least an inch of water per week! Avoid giving them frequent, but short waterings, and instead water them deeply with a soaker hose or buy a Tree Gator for hot summers or dry fall weather.
It is really important that evergreens have plenty of water leading into winter in regions where the ground freezes. Many home owners are vigilant about watering in the summer, but forget to water when the weather cools into the fall. This is the time it is most important for these trees to be well hydrated, so be sure you keep those hoses and sprinklers going until the first freeze.
Evergreens are very slow growers and can generally absorb most of the nutrients they need from the soil. In very sandy areas or areas where the soil pH is more basic, your evergreens may have difficulty absorbing the nutrients they need. If your trees seem to be unnaturally pale green, they may need a little nitrogen. Never add fertilizer to the planting hole of your evergreens! If you fertilize at all, use a balanced, slow-release fertilizer or one designed specifically for evergreens, like Jobe’s Evergreen Tree & Shrub Fertilizer Spikes.
Siting your evergreens properly, watering them regularly, and ensuring that they have the proper nutrients will help your plants stay healthier and less susceptible to common evergreen problems. Unfortunately, even with the best care your trees may still be challenged by some common pests and diseases. Because a fungal disease can look like salt-spray, windburn, or leaf miner damage, you should consult with an arborist before you begin any kind of treatment. An arborist can also assess if the damage is reparable and weather the problem has spread to other trees in your yard. If you can’t find a certified arborist, you can always contact your local cooperative extension for advice.
Proper care for your evergreen trees and shrubs shouldn’t have to be rocket-science. Mostly, it is about treating these plants like any of your other favorite plants–make sure they are planted in a good spot and don’t neglect them too much. No (living) plant is maintenance free, and if you want your evergreens to stay healthy and beautiful, aren’t they worth a little extra TLC?