How to Plant a Tree

Digging

Dig a hole twice as wide as the root ball and slightly shallower than the root ball. (The root ball is comprised of all the roots contained in a pot. The top of the root ball begins where the roots start to emerge from the trunk.)

Plant Hole

If your planting hole has slick sides, roughen the sides and bottom with a pick or shovel. This makes it easier for root tips to penetrate into the native soil.

Container

Be gentle but firm when removing the container from your tree, making sure to protect the foliage. Lay the tree on its side with the container end near the planting hole. Hit the bottom and sides of the container until the root ball is loosened. Slide the pot off the root ball and gently lower the tree into the hole.

Roots

Check the root ball for circling roots. If circling roots are left in place near the trunk, they will cut into the trunk as the trunk’s girth expands. Gently uncurl and straighten the roots so that they are going outward from the trunk. If a circling root is too stiff to move, you may need to cut it off, but be careful not to cut off too much of the root ball. If cutting circling roots will account for too much of the root ball, wait a year so that more roots will have grown. Do this quickly and shade the tree roots from the sun, so they do not dry out and die.

Trunk

If soil covers the base of the trunk, it will lead to rot. Aim to have the top of the root ball about 1/2 to 1 inch above the surrounding soil surface, making sure not to cover it with soil unless roots are exposed. Adjust the hole depth by lifting the tree out of the hole (lift it by the root ball, not by the trunk) and adjusting the soil level in the planting hole.

Orientation

Orient the tree while you have the chance. Situate it so that branches won’t be in the way of pedestrian or car traffic. If you prefer a particular side of the tree, turn it toward a prominent viewpoint (such as your kitchen window). In sunny areas, orient the tree so that the best-shaded side of the trunk faces southwest. When turning the tree, lift it from the base of the root ball, not from the base of the trunk.

Upright Position

Once the tree is in the hole, stand back and make sure it’s standing upright. Tilt the root ball until the tree is straight, then backfill firmly under and around the root ball.  Now fill the hole with water.

Boost The Soil

If your native soil is hard to work with (e.g., heavy clay) or retains little moisture (e.g., very sandy), you can treat it to some organic amendment, such as bone meal. The amendment won’t be a permanent solution to soil deficiencies, but it will help retain water and air in the soil around the root ball for the first few vital years. If adding soil amendment, always mix it with soil from the planting site; about one part amendment to three parts native soil is a good proportion for backfill soil.

Amendments

After you plant your tree, there are certain products that can be added to the soil to help the roots establish themselves. An organic root-promoting fertilizer can help, but ensure that the fertilizer is not simply placed in the planting hole. Fertilize the soil around the planting hole as well to promote root expansion.

Backfill

Pack down the soil as you backfill. Using the heel of your foot or the handle end of the shovel, press down firmly to collapse any large air pockets in the soil. This will help stabilize the tree in the hole. Don’t wait until the planting is finished; press down every few shovels of soil.

Watering

Build a watering basin around the root ball by creating a berm a little larger than the root ball perimeter. This concentrates water to the root ball. A tree that has a dry root ball can stand in a moist backfill without absorbing water. You’ll need to water your tree thoroughly after planting with about 15 gallons of water. Monitor your tree’s water needs at least once a week for the first month.  This will give you an idea as to the frequency your tree will need water growing in your particular soil.

Stakes

Remove the nursery stake that came tightly tied to the trunk after planting. Stake the tree loosely for protection or support if needed. Use only soft, pliable tree ties. Do not use wire, even if it’s inside a hose. Wire can cut into a trunk. If the trunk can’t stand up on its own, stake it so that it stands upright.  The stakes should be placed outside of the root ball. Plan to remove stakes as soon as the tree can support itself, in 6 to 12 months.

Mulch

Cover the entire planting area with a 3 to 4-inch layer of mulch, but keep it 2 inches from the base of the trunk. Mulch keeps the topsoil temperate for root growth, reduces surface evaporation of water, slows or stops weed and grass growth around the base of the tree, and prevents a hard crust from forming on the soil surface.

General Comments

The most common mistake when planting a tree is digging a hole, which is both too deep and too narrow.Too deep and the roots don’t have access to sufficient oxygen to ensure proper growth. Too narrow and the root structure cannot expand sufficiently to nourish and properly anchor the tree.

As a general rule, trees should be transplanted no deeper than the soil in which they were originally grown. The width of the hole should be at least 3 times the diameter of the root ball or container or the spread of the roots in the case of bare root trees. This will provide the tree with enough worked earth for its root structure to establish itself.

When digging in poorly drained clay soil, it is important to avoid “glazing” Glazing occurs when the sides and bottom of a hole become smoothed forming a barrier through which water has difficulty passing. To break up the glaze, use a fork to work the bottom and drag the points along the sides of the completed hole. Also, raise the bottom of the hole slightly higher than the surrounding area. This allows water to disperse, reducing the possibility of water pooling in the planting zone.