October begins the perfect time of the year for planting trees and shrubs because the temperatures begin to drop in the fall. Sometimes though, gardeners run into problems with properly planting woody ornamentals. The first step to success is to choose the appropriate tree or shrub for the specific site in the yard. As far as the plant is concerned, this means having the correct amount of sunlight. However, another leading cause of tree and shrub failure is poor planting technique. Many gardeners often plant trees or shrubs too deeply and do not ensure that the root flare is above ground. The proper planting depth plays a vital role in oxygen exchange for tree and shrub roots. Symptoms of planting too deeply may not be exhibited until several years down the road. The lack of oxygen to the roots causes poor root growth and development, which in turn can lead to an infection from plant pathogens that cause root rots. An easy way to ensure the root flare is planted in the correct position is to plant the top of the root ball no deeper than the surrounding soil. If a tree has already been planted, this can be checked by digging down until the root flare is fully exposed. Most gardeners are surprised at how much digging it saves them!
Another mistake is not letting trees and shrubs establish in the native soil. Many gardeners often remove all the native soil from the planting hole and replace it with either potting mixes or other soil conditioners. This is especially a problem in clay soils because the planting hole and this material essentially become one giant inground pot. Roots grow in the nice rich amendments, but then do not move out into the surrounding soil. A better option is to break up the soil from the planting hole and use it as backfill. Use a soil conditioner as an amendment to mix into the top 6 inches of soil, but at no more than 20% by volume. This will closely mimic the soil layers found in nature, and the result will be stronger, longer-lived trees and shrub.