Tree tips: Fall is a great time of year to plant trees
03 Sep 2017
Trees offer us a host of environmentally friendly qualities. Here are ways to return the favor when we plant them.
By Sara Bruskin Autumn is famous for its harvest-themed hooplas, but before that hard cider goes to your head, remember that harvest time for some is planting time for others. This time of year is great for planting trees, as it’s easier for root systems to grow when the air has chilled but the soil is still warm. (There are exceptions to this, so be sure to check the planting recommendations for your specific tree to confirm the ideal planting season.) Planting trees is a big environmental boost for the planet, but there are extra steps you can take to make sure your new addition is especially environmentally friendly.Choose Natives
Planting trees that naturally grow in your locale helps to conserve water and avoids excess fertilizer use because that species has evolved to survive and thrive in Colorado. Testing the soil around your house is still a good idea, as the conditions in your landscape may be more compatible with some native trees than others.
If you desperately want a tree that isn’t native to these parts, make absolutely 100-percent sure it is not considered invasive to this area. Invasive species can decimate ecosystems, and we already have some serious offenders here. Some of Colorado’s worst invasive trees are the Russian olive, tamarisk, Siberian elm and tree of heaven (Ailanthus altissima). Tree of heaven is so hard to kill that one managed to survive in Hiroshima less than 1,000 feet from the atomic-bomb detonation in 1945—and it still grows there today. The species also contains chemical compounds that can be hazardous to plants growing nearby, so be careful about planting trees that are not explicitly recommended by local arborists.
Don’t Be Vulnerable
Dustin Brown, of Boulder’s Blue River Forestry & Tree Care, recommends planting trees that aren’t prone to diseases and pests. “This will help prevent the need for future pesticide applications,” he says. “While there are botanical and organic options for treating harmful pests and pathogens, the best way to avoid using them is through proper tree-species selection and promoting local tree diversity.” Pesticides are extremely toxic to the environment, so planting trees that won’t need these treatments gives you major green points. Because we can’t always anticipate which trees will be the target of new bugs and blights, ecological diversity is a must. If your neighborhood is all Rocky Mountain maples, pick something else to plant. Ecosystems are strongest when they have a lot of variety, since different species are susceptible to different attacks and a wide range of trees means a greater chance of survivors when bad times roll around.
Perfect Placement
Gas Gobblers
If you want to select a tree specifically for its ability to combat climate change, there are three things you’ll need to consider: efficiency, space and life span. Some trees naturally take in more carbon dioxide and chip away at greenhouse gas levels more efficiently. In Colorado, some of the best carbon-containing trees are ponderosa pines, Douglas firs, aspens and oaks. Because the carbon-containment capability of any given tree increases with its size, plant the largest tree that your space will allow (but again, keep pruning and other maintenance requirements in mind).
Irrigation & Nutrition
Once established, native tree species should be fine without additional watering, but newly planted trees need some help. Installing drip lines is the best way to water trees. Drip systems use less water over a longer period of time, so the water gets fully absorbed by the tree rather than pooling and creating runoff. Blue River’s Brown suggests installing additional drip lines in a larger radius around the tree in anticipation of future root growth. “Keep in mind that the magic happens out on the tips of the roots,” he says, “so it’s important to keep that area hydrated.”
