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Rows of young maple trees in plastic pots on plant nursery

When choosing or planting a landscape tree, think about the mature height of the tree and how much space will be required for the tree. Plant the right tree in the right location. Trees can add beauty and value to a landscape, so following the best practices for proper tree planting will ensure better growth.

Choosing a Location

It may be best to stay 50 feet or more from a swimming pool, septic tank, field lines, vegetable garden, and flower beds. If there are any above-ground or below-ground utilities in the area, it may be best to choose another location. If trees are planted in heavy shade, they will probably grow very slowly and possibly not grow as straight as one would like. However, early morning and late afternoon shade can be an advantage for species with thin bark, such as maples.

Correct Planting Procedures

When purchasing bareroot plants from an Arbor Day tree event or a store, if the trees cannot be planted immediately, they should be healed-in. The term “healed-in” means to bury the roots in compost or soil to prevent them from drying out until a later planting date. This could be as simple as several trees being placed in the same hole or laid down and the roots covered with soil or compost. This is a temporary procedure to keep the tree roots from freezing or drying out for up to a couple of weeks—until time or conditions are favorable for proper planting.

Dig a hole at least twice the diameter of the root ball, but no deeper than the root system/rootball. It may even be best to dig the planting hole two to four inches shallower than the root ball. This is important with all trees, but extremely important when planting balled and burlapped trees.

Balled and burlapped plants are dug and sold with native soil around the rootball, and can be extremely heavy. These heavy root balls may be planted at the correct depth, but can sink after planting and bury the trunk and roots too deep. It is not uncommon for a rootball to sink several inches after being planted in a hole at what seemed to be the correct depth.

When planting the balled and burlapped plant it should rest on the firm, undisturbed soil at the bottom of the planting hole. Keep in mind that it is not only heavy, balled and burlapped trees that can sink in a planting hole. Sinking can also happen to larger container grown trees. Even bareroot or smaller container grown plants can settle in the planting hole so pay close attention and plant at the correct depth.

Caring for the Roots

After digging the hole to the correct size, check for glazed sidewalls. In a clay soil, it is common to create glazed/slick sidewalls while digging. These slick sidewalls interfere with the roots’ ability to grow past the planting hole and into the undisturbed soil. If the hole has glazed sidewalls, simply scar up the slick places with a shovel and continue with the planting procedure.

Planting Bareroot Trees

For bareroot trees, spread the roots out broadly over a small mound created in the bottom of the planting hole. When planting containerized trees, pull the circling roots loose with the fingers or cut shallow slits in the root ball to encourage the roots to grow outward instead of continuing to grow in the circular pattern. Wash away as much of the potting material as possible and plant as described for a bareroot plant.

Planting Container-grown Trees

When planting large container-grown plants, remove the outer layer of potting mix (this is mostly pine bark) to expose lateral roots. Place the tree in the planting hole as straight as possible and at the correct depth. The top of the root ball or top roots for bare root trees or container-grown plants should be at the soil surface or just above the soil surface. If there is a bare root plant with a long root that will not fit the planting hole, either dig the hole larger to accommodate the root in an outwardly growing direction or prune the root at the edge of the planting hole. Do not wrap the root around the inside of the planting hole. This will encourage the root to circle and possibly girdle the tree from underground later in the tree’s life.

Planting Balled and Burlapped Trees

When  planting balled and burlapped trees, any burlap needs to be pulled away from the trunk and cut and removed from the top of the rootball. It may be hard to remove all the burlap, especially on a tree placed in a wire basket. The goal in removing some of the burlap is to make sure no burlap is exposed above the top of the rootball. Any exposed burlap above the soil line can act as a wick and will allow moisture to be pulled from the soil. Also, if the “burlap” is a synthetic product, it will not rot, and the roots will have a difficult time growing through it.

If the balled and burlapped tree is in a wire basket, removing the entire wire basket is not recommended. However, the wire (especially the top row) can eventually girdle the tree roots later in life. For this reason, it is a good idea to remove the upper portion of the wire basket after the tree is placed in the planting hole but before all the soil has been added around the rootball.

Filling the Hole

Refill the hole with the backfill that was removed from the planting hole. It is not a good practice to amend the backfill soil with organic matter unless the entire planting bed/area is amended. Partially fill the planting hole with the native soil around the root system while keeping the tree as straight as possible.

Use a shovel to break up clods and spread the soil around the roots while trying to eliminate any air pockets. Adding water can get messy but does a great job in eliminating air pockets. Do not try to eliminate air pockets by stepping on the backfill as this can cause compaction. Repeat this procedure until the soil is even with the top of the root ball or even with the top root for bare root plants.

Care for the Planted Tree

Water

Water the tree deeply the day it is planted. Keep in mind that soil can be saturated on top but still very dry just a few inches below the surface. The best time to plant trees would be during the dormant season because they will require much less watering. However, it is possible, especially with container grown trees, to plant during warmer times of year.

If a tree is planted during the growing season, it is important to water at planting and anytime additional water is needed. This usually means watering every couple of days for a few weeks and continuing to provide some supplemental watering throughout the first summer and fall.  Depending on the size of the tree, it may take 10 to 20 gallons of water to sufficiently water the tree at planting. A good rule of thumb is to use two gallons of water for each inch of trunk diameter (near ground level). For example, a five inch diameter tree would need 10 gallons every couple of days and decreasing frequency and increasing volume over time.

Mulch

Mulch is important to keep the soil cool, conserve moisture, and will aid in weed management. Materials such as pine straw or pine bark make excellent mulches, but other materials can be used as well. The mulch should be spread about four times the diameter of the root ball. For large trees, this can be six to eight feet from the tree, and a four-foot mulch diameter should be a minimum for young trees. The mulch layer should be no more than one inch deep over the root ball, but two to three inches from the edge of the root ball and beyond. At the trunk, the mulch layer should be very thin and should never be piled up against the trunk as this can cause various diseases. Managing weeds and mulching around the tree will greatly increase the growth of the tree and eliminate the need for mowing or string trimming around the tree trunk. Again, do not use a string trimmer around the trunk of the tree.

Staking

Most of the time container grown and balled and burlapped trees do not need staking. However, pay attention to the trees. If tree stability is a problem, then staking is encouraged. Do not drive a stake on top of the root system or even into the freshly dug planting hole. Drive a stake or stakes in the harder ground outside of the planting hole. Feed string or wire through a piece of old water hose to protect the tree from being girdled from the staking materials. Leave the tree staked for no more than one growing season. It is also a good idea to check the tree periodically to make sure the staked tree is growing properly and the stakes or staking materials are not causing any problems.

Other Maintenance

Fertilizing is not recommended the first year, but weed control, mulching, and irrigation are recommended. Unless there are damaged limbs, wait until the second year to do any corrective pruning. Remember that leaves make roots, so take care to remove as few leaves as possible.

A soil test will tell identify necessary nutrients, so a fertility program could begin at the start of the second growing season. In order to keep the trunk straight, make sure the lateral branches stay subordinate to the central leader. The lateral branches should be smaller in diameter as well as height to the central leader. If a lateral branch competes for the central leader position, a fork will develop and will be a weak place in the tree and be subject to splitting during a storm.

These are just a few thoughts for tree planting and care. Remember to plant the right tree in the right place and call on the local Extension office with additional questions.

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