Planting Trees and Shrubs – Preparation

Every method used by plant nurseries to package trees and shrubs – balled-in-burlap (B&B), container-grown, containerized, or bare-root – may lead to a flawed mature root system. Defects may be roots buried too deeply, removal of portions of functioning root systems, or circling and kinked roots.

Until recently most tree-planting guides have ignored root problems created under plant nursery conditions. Edward F. Gilman, University of FL Professor, and Laura Sadowski, Information Specialist, FL Institute of Food and Agricultural Sciences, tackle the problem of ensuring quality tree root growth in Planting and Establishing Trees, Ch. 11, September 2007.

Barbara Leach, Horticultural Associate, Agriculture and Natural Resources, Virginia Cooperative Extension, recently made use of Gilman and Sadowski’s material while presenting a workshop in Roanoke, VA. Leach emphasized steps needed to ensure quality tree and shrub root growth in well-drained soil.

Dig Planting Hole

This should be shallow, about 90 to 95% of the space between the top root and bottom of the root ball, and wide, a minimum of 1.5 times the diameter of the root ball. The topmost root should be about 2 inches above the soil surface. The wider the planting hole, the more successful new root growth will be. Most effective tree roots grow in the upper three feet of the soil, with close to seventy percent in the first foot.

A major indication of an improperly planted tree, says Leach, is a trunk that appears to disappear straight down into the soil. This indicates that the root ball is planted too deeply. (Photo #1) A properly planted tree shows topmost roots and the root flare at or slightly under the soil line.

Inspect and Fix Roots

Deeply buried top roots indicate a loss of substantial amounts of healthy root system, especially in field-harvested plants. Remove excess soil in containers and root balls that bury the root flare – portion of trunk from which roots emerge – (Photo #2) or top roots if tree has not yet developed a root flare. This step ensures proper placement in the planting hole.

Roots should radiate like spokes of a wheel. Cut kinked, crisscross or circling roots visible at the top or around the perimeter of the root ball. This prevents development of girdling roots and ultimate strangulation and tree death. (Photos #3 & #4)

Position Tree

Move plants by taking hold of the root ball or container. Clutching trunk or branches will damage them as well as the roots.

The topmost root should be 1 to 3 inches above the landscape soil line. Research shows it is better to plant too high than too deeply. (Photo #4) Stabilize the plant’s position by placing a small amount of soil around the root ball.

Reference

Gilman, Professor Edward F., Department of Environmental Horticulture; University of Florida and Laura Sadowski, Information Specialist, Institute of Food and Agricultural Sciences, Gainesville. Planting and Establishing Trees, Chapter 11, PUBLICATION ENH 1061, original publication date September 2007, Urban Forest Hurricane Recovery Program series of the School of Forest Resources and Conservation and the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida.

Articles about Tree Care

• Planting Trees and Shrubs – Installation: Backfill, Mulch, Stake and Prune to Ensure Good Establishment
• Tree Death in the Landscape: Manage garden and urban trees for health and longevity.