How To Plant A Tree
Trees provide many benefits to a community. They create the oxygen we breathe; reduce air and water pollution; reduce storm water runoff; provide shade; reduce energy costs; reduce the urban heat island effect; and act as wind breaks, sound barriers, and visual screens. They improve our quality of life in enormous ways.
Trees are among the longest-lived organisms on earth but the average lifespan of an urban tree is only a fraction of its natural potential. This is due mainly to conditions created by people and the urban environment. Choosing the right tree for the right site, proper planting and proper care will give your trees the healthy start they need to grow strong and live long.
The best time to plant a tree is late winter/early spring prior to buds opening, or late fall after the tree goes dormant, or hardens, and before the ground freezes. The height of summer is not the best time to plant trees. They are easily stressed by heat and the lack of adequate water, which is the greatest threat to a newly planted tree's survival.
Consider These Questions Before Purchasing Your Trees
Function of the tree
What purpose do you want the tree to serve?
Do you want it to provide shade, a visual screen, act as a windbreak, provide food and habitat for wildlife, prevent soil erosion, improve aesthetics, or compliment existing landscaping?
Physical constraints of the planting site
How close are neighboring buildings, the sidewalk, and the street?
Are there overhead or underground utilities?
How much space is available for the roots and/or branches to grow?
It is important to remember that the majority of a tree's roots (80%) are within the top 18" of soil and they extend farther than the canopy of the tree.
Also, it is best to choose a tree whose canopy, when mature, will fit in the area planted rather than to prune a large tree to fit in a smaller space.
Other Site Conditions
Consider the amount of sunlight the planting site will receive.
Is the site excessively windy?
Is the soil wet or dry?
Will the site be exposed to salt?
Also consider soil pH and soil texture.
Once the site conditions are determined a tree species, or cultivar, can be chosen to fit those needs and restrictions. The more comprehensive your site assessment, the more likely your tree choice will thrive in its new location. Helpful resources offering more detailed explanations of site evaluation and lists of tree species well suited for various urban site conditions are listed below.
When purchasing trees from a nursery choose healthy specimens, check for injuries or structural defects. The web link for the American Standard for Nursery Stock is listed in the right column.
Trees may be purchased in one of three ways: container grown, balled and burlapped (B&B), and bare root. There are benefits and drawbacks to all three forms.
Bare root trees are usually only available through catalogs and are shipped during short periods in the spring and fall. The benefits of bare root trees include a lower cost per tree, lighter handling weight because there is no soil around the roots, and if dug properly, bare root trees have a greater portion of roots kept in tact than B&B trees.
Tree Planting Diagram
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Container grown trees may have roots that encircle the root ball in the pot. Spiral roots can harm the tree and even kill it if they are left to develop. The benefits of container grown trees are that they usually weigh less than B&B trees, there is less disturbance to the roots when planting containerized trees, and they are available at most nurseries.
B&B trees are much heavier than bare root trees and lose a substantial amount of roots when dug at the nursery. But large amount of soil in the root ball does benefit the tree by protecting its roots from injury and helps keep them moist. Roots should be kept covered, out of direct sunlight and moist. Do not allow the roots to dry out regardless of the form in which the tree is purchased.
Plan in advance to prevent damage to trees from snowplows, lawn equipment and/or other harmful activities. This should be considered when choosing a planting site as well. Some forms of protection include mulching, staking, curbing and fencing.
Before planting, prune only dead or broken branches. At this stage, trees can use all the potential leaves they can grow. Begin structural pruning after the first year. Painting wounds is no longer an accepted practice. It does not prevent decay or cure infections, and it may actually hinder the tree's natural efforts to seal its wounds.
Diagram of balled and burlapped tree
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Balled and Burlapped -
Dig the hole only deep enough for the root ball. Firm soil under the root ball will prevent settling. Dig the hole 2-3 times the width of the ball to allow the roots to grow, spread and establish more easily. Once the tree is in the hole, remove twine, wrap and wire baskets with minimal disturbance to roots. While these materials help protect the root ball during shipping, they can cause growth barriers and baskets may cause girdling of roots as the tree matures. Backfill the hole firmly packing the soil around the tree and roots. Water deeply
Bare root trees should be planted within a few days of shipment to help insure survival. Keep roots moist and cool until planting time. Remove all packing materials and soak the tree roots in water before planting. Dig a hole wider than the roots so they may spread without crowding.
Container-grown trees is the last option when purchasing a tree. Before the tree is removed from the container, a hole should be dug and watered thoroughly. The roots of containerized trees may spiral within the pot. Help prevent root girdling by untangling or vertically cutting any roots that encircle the root ball. Loosen the soil and roots prior to planting, this will let the roots spread out more freely while allowing fresh soil to be applied directly to the root system.
Soil amendments are not recommended for lawn plantings. Backfill with the existing soil. Planting sites along streets often offer very little space for tree roots to grow. Structural soil is often recommended under roads and sidewalks to increase the potential area for root growth. Structural soil is a mixture of a particular stone with soil, and it meets the load bearing requirements for the subsurface of pavement and sidewalks. The unique stone/soil mixture provides space for tree root growth, aeration, drainage, and access to nutrients. Trenches also allow for more root growth than individual tree pits. Use of paving materials that allow water to permeate the root zone will increase the success of the tree. When roots have adequate space to grow, they are less likely to damage sidewalks and the trees will be healthier.
Plant the tree so that the trunk flare is at the soil line. The trunk flare is the point at which the roots begin to branch from the trunk. Do not plant too deeply. Water as you backfill the hole, to remove air pockets and firmly set the tree. Gently tamp soil. Staking for support is not usually necessary. Studies have shown that trees develop stronger trunk and root systems if they are not staked at the time of planting. However, protective staking may be required on sites where lawn mower damage, vandalism or very windy conditions are concerns. Apply 2-4" of organic mulch at least the width of the crown. Mulch should not touch the trunk or trunk flare. Do not mound the mulch up against the trunk as this will damage the tree.
Adequate water is essential for newly planted trees. Water trees, soaking the root zone, at least once a week, barring rain, and more frequently during hot weather. When the soil is dry below the surface of the mulch, it is time to water. Too much water can be as harmful as not enough. The right amount of water depends on the site conditions and tree species. Tree-gators can also be very useful. Gators are a portable drip-irrigation system that provides a slow release of water reducing the possibility of too little or too much water applied to newly planted trees. They also reduce labor costs.
Fertilizing the first year is not necessary.
Choosing the right tree for your planting site, planting properly and caring for your tree over time will help ensure your investment will pay off for many years to come. For more information on planting and choosing the right tree for the right place contact your local DEC Forester.