Planting Trees and Shrubs

There is an old Chinese proverb that says in essence; the best time to plant a tree was twenty-five years ago and the second best time is now.

Before choosing a tree visit your regional arboretum to see the mature tree growing in the landscape.

I agree wholeheartedly with just one small qualification. Although trees can be planted almost all growing season; spring really isn’t the best time to plant your new tree. In the spring, trees are in the process of breaking dormancy and are exuberantly sending up new succulent growth. Naturally, they require a lot more energy and water, which is only intensified if they are newly planted or transplanted.

By early summer, trees take a break and their growth rate starts to slow down. When their growth rate slows down, so do their water requirements and with reasonable care (watering and mulch) a newly planted tree’s chances for survival will be much improved.

There are some trees, however, that are slower to root and need a full growing season. If you are planting birch, oak, magnolia, ginkgo, the American hornbeam, yellowwood or hemlock, it is best to get them into the ground early in the spring.

Steps to Planting a Tree for Lasting Health

1. Choose the location wisely. If there are wires, buildings, light or telephone poles nearby that will impede the natural growth of the tree’s canopy—plant elsewhere. When you have decided on the best location call your local utility company and have them send someone to mark all your underground utilities.
2. Water and prune if necessary. The root ball should be moist before planting. Prune out only broken or diseased branches. Terminal buds produce auxins, which are the hormones that promote new roots. The more terminal buds you leave, the faster the tree will recover from transplanting.
3. Ease the tree out of the container. Look for roots circling around the edge of the root ball. If you do find circling roots, take a sharp knife and slice into the sides and bottom of the ball. If pot bound roots aren’t disturbed before planting they may continue to girdle the tree causing stunted growth and even death. After checking for girdling roots, remove all the soil from the top of the root ball until you come to where the first root emerges from the trunk. This is called the root flare and it is very important to the future good health of your new tree. The root flare should never be covered with more then one or two inches of soil. Too much soil over the root flare cuts down on the amount of oxygen and water to the main support roots and may also encourage new girdling roots to form above.
4. Measure the distance between the root flare (top-most root) and the bottom of the root ball and then subtract about 10%. That’s how deep your planting hole should ideally be. Width of the hole may vary depending on your soil type. The hole should be at least twice the diameter of your container, however, if you have heavy clay then five or six times the diameter would not be excessive. Basically, you can go too deep, but not too wide–no matter what your soil.
5. Start digging your hole. Taper the sides of the hole and then rough them up so the roots will more easily find a means out of the hole and into the surrounding soil.
6. Carefully slide the tree into the hole. Never lift a tree by the trunk, but instead carefully move the plant by holding the root ball. When the tree is in place, take a straight stick and place it over the top of the root ball. It should be a few inches above the surrounding soil level. Things happen, so if you went a little deeper then you thought, tip the tree to the side and pack soil underneath tamping it down hard with your foot. Keep adding soil until you reach the desired height. Remember, better a little too high, then too low.
7. Straighten the tree. Have someone look at the tree from several angles to make sure it is straight.
8. Start to backfill with the soil. No soil amendments such as compost or peat moss are needed. If a tree is in an amended hole it keeps its roots just in that nice, soft, comfortable hole and they don’t venture elsewhere. As you backfill, break up large clods and work the soil around the root ball. Don’t step on the soil to pack it down to get rid of air pockets. You don’t want to compact the soil and watering will eliminate most large air pockets anyway. The smaller air pockets are actually beneficial and allow more air to reach the roots. When the hole is filled the root ball should be a few inches above the surrounding soil. (See Diagram).
9. Apply mulch to an area about 6-8 feet in diameter around (but not on top of) the root ball. Make a dam or berm with soil or mulch around the perimeter of your filled hole and slowly fill this basin with water. When the water is gone, fill it once more.
10. Stake the tree only if necessary. The University of Minnesota Forest Resources Extension says, “Staking should only occur when the newly planted trees have abnormally small root systems that can’t physically support the larger, above-ground growth; when the stem is spindly and bends excessively when it is not supported; when the planting site is very windy and trees will be uprooted if they are not supported, or when there is a good chance vandals will uproot or damage unprotected trees.” For more information on how to correctly stake a newly planted tree, please see their webpage at http://www.forestry.umn.edu/extension/urban_com/staking_guying/StakingandGuying.html.
11. Keep your new tree well-watered, but never water automatically without first checking the soil. If the soil is dry or just slightly damp at about 4 inches deep, then it is time to water.

Now that you have the tree planted, mulched and watered–should you throw a little fertilizer on top? That one is still up in the air. Some say yes, some say no. In my case, I just can’t stand to plant anything without adding at least a little organic fertilizer. What gardener can?