How to Plant a Tree
The level of care makes a difference in how trees will grow and develop. The goal of tree planting is to have a vigorous, healthy tree that lives to the limits of its natural longevity. Achieving this goal begins with careful tree selection. Next, the tree must be handled carefully until it is safely installed in its new home.
These two cardinal rules will help keep trees alive until they can be planted.
- Carry trees carefully. When transporting, load and unload gently, being careful not to break branches. Always provide support beneath balled or potted plants.
- Keep roots moist! Techniques to prevent drying vary, depending on the trees and how long you must store them before planting. Balled and burlapped or potted trees should be checked for dryness by finger-length probing into the soil. Sprinkle or water as necessary. Then store them in a cool garage or shaded area out of the wind.
Planting Containerized Trees
Recommendations for planting have evolved in recent years as more is learned about the nature of roots and urban soils. Local conditions make generalizations difficult, but here are some guidelines that reflect the latest opinions of tree experts.
The Planting Hole
Proper preparation will encourage root growth rather than adding to the difficulties already challenging the young tree. Most roots spread through the top 12″ of soil in a wide periphery around the tree. Therefore, slope the side of the hole and dig or deeply rototill an area around the hole at least twice the diameter of the container.
How Deep Should You Plant?
Under normal conditions, planting even with the surrounding terrain best encourages root growth. When wet conditions or heavy soil are problems, raising several inches of the root ball above ground will aid the spread of lateral roots. In arid climates, a basin can be used to collect precious water.
Filling the Hole
Backfill with native soil unless it is clay from basement excavation or other undesirable fill material. In that case, blend together one part washed sandy loam, or bring in as much good topsoil as possible. Tamp gently and ad water to fill large air spaces and to give the tree its first good drink in its new home. Do not use excessive tamping around tree base: compacted soil may inhibit the spread of roots. Rake a ridge of soil two to four inches high around the margin of the hole.
Following Up After Planting
Watering is the key to tree survival. It should be used when filling the planting hole to eliminate large air cavities, firm the soil around fine roots, and provide nourishment for the new tree. During planting, bare-root trees can be dipped in water-absorbing polymers. This amazing chemical comes under a variety of brand names and is available from nurseries. Its function is to attract water when abundant and hold it longer than the soil when conditions get dry. It can also be used with balled and burlapped trees, being mixed with the backfill. The effects last for about two years. With or without the aid of polymers, water deeply around your tree once a week during warm, dry spells.
Unless directions specify otherwise, it is better not to prune after planting if the tree will be watered regularly. Leaves manufacture the food needed for root growth, so the young tree needs as much of its crown as possible. Exceptions to this rule include trees that will be exposed to strong winds or drought conditions, in which cases rarely pruning will reduce the demand for water from its roots. Always prune dead or broken branches. The best time to prune oaks are in winter and midsummer.
Avoid fertilizing shade trees until late spring of the second year following planting. Fertilizers can “burn” roots or stimulate crown growth faster than the roots can supply water.
Stakes and guy wires should be used only if support is necessary. When using, avoid common problems by following these guidelines. If the main stem droops, find the best place for support ties by moving your hand up the trunk to locate the point above which the top can stand up on its own. Place the support ties about 6” above the point. Ties can be made many ways, but a loosely-fitted figure 8 tie made of polyethylene, cloth, or webbed strap is easy to install, provides good support and cushions the tree from rubbing against the stake. Using two ties will also minimize the chance of bark damage from rubbing. Regardless of the tie used, allow slack for sway.
Mulch is a young tree’s best friend. It holds down competing weeds or grass, retains soil moisture, prevents soil cracking that can damage new roots, protects the trunk from lawnmower damage, and helps prevent soil compaction. Organic mulches such as wood chips or pine needles also contribute to better soil structure and aeration as they decompose. Avoid limestone rock and allow no mulch to touch the tree’s trunk or be piled higher than 2 to 3 inches.
To give your tree a long, healthy life:
- Handle carefully
- Dig hole 2x the width and same depth as the root ball
- Remove tree from container
- Prune spiraling roots
- Put tree in center of hole so root ball is level with surrounding soil
- Fill in hole using existing soil, not potting mix or soil additives
- Use surplus soil to form “saucer” around tree base
- Remove air pockets by soaking planting hole
- Add 2” of mulch
- No root stimulant or fertilizer for 12 months
- Stake only if necessary