As summer starts to wind down, fall outdoor projects come into focus: time to start putting perennials to bed, time to pull the bygone annuals, time to sharpen and clean tools. And time to plant a tree — or two.
The benefits of trees are almost endless: trees provide shade and cooling, take in carbon dioxide and release oxygen through photosynthesis, help remove air pollutants, hold and help replenish groundwater, decrease soil erosion, provide habitat and food for wildlife, reduce anxiety and add beauty.
And the benefits of planting in the fall are myriad as well. Cooler soil helps healthy tree roots develop more quickly and secure nutrients before winter sets in. Weeds are fewer in autumn, as are insect pests and diseases, and rain is often more abundant. The cooler air is less stressful for both the trees and those planting them, so it’s a good season to put in a tree.
But where? Stay away from power lines for tall trees, and avoid underground structures like septic systems which could affect the roots. Recognize town right-of-ways, which in Houlton are 25 to 33 (depending on which street) from the middle of the road.
Take into account the tree’s needs for suitable soil, sunshine and water, and how tolerant it is of winter salt. Consider the height and breadth of the tree when it is full grown, not simply in its current size, and locate it where it will thrive.
Deciding what kind of tree to plant is a delightful adventure that may require a bit of research. Start with the hardiness zone, a guideline based on lowest winter temperatures — Houlton’s is 4b — as well as your own desires and space.
Here are some deciduous (leaf-dropping) possibilities.
Large trees (45-plus feet): red maple (such as armstrong, karpick, bowhall, red sunset), which tolerate wet sites and have some salt tolerance; sugar maple (green mountain, majesty); oak (northern red, bur, swamp white), which need lots of space; and lindens (littleleaf, small-leaved lime), which are not salt tolerant.
Medium trees (25-45 feet): sugar maple (sugar cone); honey locust (skyline, halka), tough and good for difficult sites; American hornbeam, compact and useful for screening.
Small trees (15-25 feet): flowering crabapple (pink spire, sentinel); shadbush (robin hill), good in moist spaces with light shade; hawthorn (crus-galli, thornless cockspur), with June flowers and winter red berries.
The University of Maine Cooperative Extension also has lists of trees that include those native to Maine, which are always a good choice. Or you may opt for evergreens, such as spruce (white, serbian, colorado blue), pine (swiss stone, scots), northern white cedar, and white fir.
When selecting a tree to buy, look for one with a strong, healthy trunk and well-distributed branches, and no insect or machine damage. Bare-root trees should have roots that are moist and branching; balled or burlapped roots should be firm to the touch; container roots should be small and not circling.
And now to planting. For bare-root trees, first gently untangle the roots and soak them in water for 3 to 6 hours. To unpack container trees, tap the pot to loosen it and remove the roots with soil intact, then score the bottom and sides. Trees with burlapped roots should be moved by the ball, not the tree trunk.
In your planting space, dig a wide hole two to three times as broad as the roots, and as deep as the root ball for container and burlapped balls. Set the tree at ground level or just above, compacting the soil at the hole bottom if it is too loose. For bare roots, spreading them over a cone of loose soil at the bottom of the hole will hold them in place during backfilling. For burlapped ball roots, cut vertically up the wire basket, remove twine and nails, then fold and cut away burlap on the sides (leave the bottom on unless it is treated or vinyl).
Then backfill, packing soil in gently so there are no air pockets. When the hole is about two-thirds full, fill it with water, let the water soak in, then finish backfilling. Create a shallow holding basin around the tree for water, mulch with wood chips or bark, and keep the mulch from touching the trunk. Keep your tree watered well, especially in the first year.
Then enjoy the beauty and the shade, the growth and the birds — and all you are doing for the planet by planting a tree.
These tips and ideas are brought to you by the Houlton Canopy Crew, committed to caring for trees and gardens.
