October through February are great times to plant trees in our area so they can get settled in before the hot, drought season. Planting a tree correctly and following up with good initial maintenance are essential. A healthy plant will survive disease, pests, drought and other stresses to its environment. The most common cause of poor tree health is poor planting: too deep, too shallow or in too small an area. The objective is to plant the tree so that the root flare at the bottom of the trunk is at or slightly above the surrounding ground level.
Remember that the root system of a tree grows out much farther than the canopy. The roots of young trees must be able to spread out into the surrounding soil to find water, oxygen and nutrients. The health of the root system determines the health of the shoot system. Grow healthy roots for a healthy tree.
CREATING THE PERFECT PLANTING SITE
Mark the planting site and remove any vegetation, including turf, from an area three to five times the diameter of tree’s root ball.
1. Create a root zone, not just a hole. Break up the soil 8 to 1o inches deep – but no deeper than the root ball – in a space two to three times as wide as the root ball. The objective is to de-compact the soil so new roots can spread out into the surrounding soil and create a strong base for the tree. This becomes especially important in times of drought, flooding and storms.
2. Examine the sides of the root ball or use a probe to locate the roots within the root ball. Then, in the middle of the prepared root zone, dig a hole deep enough so the main roots will be just below the surrounding soil.
3.Gently prune away any dried, damaged and broken roots from bare-root trees. Pot-bound container grown trees may show circling roots that should be cut through or straigtened out to prevent later girdling and to encourage natural root growth. If circling roots are severe, return the tree to the nursery for a replacement. Check visible roots on balled and burlapped trees and lightly prune any obvious broken, damaged ends or circling roots. Do not over prune roots.
4. Install the young tree at the same soil depth that it has been growing or slightly higher. A slight rise in the center of the hole will keep water from “pooling” in the bottom of the hole. The depth from the top of the small mound to the surface of the ground should be no greater than the depth of the root ball while allowing the root flare to be at or slightly above the surrounding ground level. Do not plant too deeply.
5. When moving the tree, always pick it up by the root ball, binding strings or container and not by the trunk. Turn the tree to the desired position and then set it in place. Remove all the ties and roll the burlap and other ball-wrapping materials away from the top half of the root ball. If possible, remove all packaging materials. This encourages good contact between the soil of the root ball and the surrounding soil. If the root ball is wrapped in natural burlap, the burlap can be left in the hole where it will gradually decompose. If the burlap is not natural, remove it completely.
6. Backfill with soil excavated from the hole until it is about 3/4 full. Do not fill the hole with mulch, compost, gravel or other soil amendments. Research indicates that overamended soil in the planting hole discourages roots from growing into the surrounding soil.
7. Add water and allow the soil in the hole to settle. Finish backfilling around the root ball. Use the water to float out air pockets that can cause the roots to dry out and the soil to sink. Make sure that soil fill does not cover the root flare.
8. Firm and level the soil, but don’t re-compact it solidly.
9. Don’t replace sod over the root zone or in the hole.
10. Mulch takes the place of the natural layer of leaf litter found on the forest floor, and it greatly benefits the tree. Mulch should be made of a coarsely chopped organic material like chipped or shredded hardwood or shredded pine bark, and should be applied no more than 3 inches deep, at least 3 inches from the trunk, and if possible 3 feet out to keep lawn mowers and weed wackers from harming the tree trunk.
Why Such Intense Preparation? Moving and transplanting trees “shocks” their root systems and damages the delicate absorbing roots that supply water and nutrients. The success of re-establishing root growth and function determines the eventual success of the tree. Optimum site preparation makes it easier for the roots to grow and spread out. Remember that tree roots grow far more widely than deeply.