Abstract

VAN DE WERKEN, H. 1984. Why use obsolete fertilizer practices. Am. Nurseryman 159(7): 65-71.

Obsolete recommendations concerning tree fertilization are still found in current publications. They erroneously relate the amount of fertilizer to be applied to trunk diameter, when it should be based on the spread of the tree’s root system. Also, the formulations that are recommended, such as 5-10-5, 4-1 2-4, or 6-1 2-12, are based on tests with agronomic field crops rather than shade trees. Despite three decades of scientifically designed tests by horticulturists and arborists, and extensive publication of their work, few practitioners pay attention to their findings. Many extension workers, garden writers, and book authors continue to perpetuate obsolete concepts.

• © 1985, International Society of Arboriculture. All rights reserved.