The Root of the Problem
Nursery-grown stock can have problems; here are some solutions.

By James Urban, FASLA

James Urban, FASLA

Nursery-grown trees specified by landscape architects can have serious problems. Many trees are planted with roots that are not suited for long-term support of the tree, causing decline and death. These problems include roots too deep below the soil line, kinked roots, girdling roots, and roots not sufficiently distributed in the root ball. Most of these conditions are the result of nursery practices that may start during propagation and continue until harvest, although planting methods can also affect root location and development.

The following assessment of the state of nursery material suggests a difficult road as we try to implement solutions. Nurseries, contractors, landscape architects, and other specifiers need to be educated and accept the need for change. There will be a long period where some contractors, nurseries, and designers will try to make their own corrections while others will not. In this situation bidding will be difficult. Making changes will cost money, and the playing field will not be equal between the contractors and nurseries making changes and those that are not.

Designers and consumers who buy finished landscapes on a bid basis will need to be clear in the bidding process about exactly what they expect and that they intend to enforce new requirements. Without this built into the specifications, specifiers should not expect the contractor to resolve problems. Designers and contractors must work together.

Nursery Production

Commercially produced trees are significantly different from trees that develop from seed in nature. Roots are cut off at the time of transplanting, and other important differences occur during production. Understanding propagation and nursery production processes is important to understanding how to specify or select a tree.

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