Proper preparation of the planting site is critical to good root development. In urban areas, site preparation may require special planning because of the type of planting site, such as street or parking lot plantings. Also, when preparing the site, you may find surprises when digging, such as construction bury pits, old road beds, or asphalt. These surprises can increase the time and resources needed for planting.
Three steps for preparing the site are:
Determine size of planting area
Because most root growth occurs in the upper 12 inches of soil, the planting area needs to be shallow and wide to accommodate the development of the fibrous roots. Three measurements to consider when determining the size of the planting area are:
Check planting depth depth to ensure trees are not planted too deep.
Photo credit: Michigan State University Horticulture Club
Many planting sites have weeds, grass, groundcovers, or other competing vegetation that should be removed. There are several ways to eliminate competing vegetation. The best method depends on the location and requirements of the site and the resources available.
Prepare the soil
The soil conditions at the planting site greatly influence a tree’s ability to survive the planting process and its mature health and form. Problems with soil condition should have been identified during site selection and corrected before planting. However, this is not always possible.
If planting must proceed without adequate site preparation, the soil in the planting area needs to be thoroughly loosened to encourage root growth. However, to reduce the settling of the soil after planting, do not disturb the bottom of the planting area. If this soil is disturbed, it should be pressed down to decrease settling. Roughen the sides of the planting area to help the roots penetrate glazed soil surfaces.
See other parts of this 3 part Tree Planting Series:
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By: Ed Macie, Regional Urban Forester, USFS Southern Region