Abstract

KOSKI, ANTHONY J. 1986. Can you feed your turf and still starve your ornamentals? Am. Nurseryman 164(6): 70-73, 76-77.

While most grounds managers are quite aware of the importance of turf fertilization, they may tend to disregard the important role that proper fertilization can play in the care of trees and shrubs. It is often assumed that turf fertilization alone will provide enough nutrients for both the turf and the woody ornamentals growing in the landscape. However, some experts emphasize the importance of fertilizing trees and shrubs that are growing outside their native habitats, such as those planted in lawns. The most important nutrient in a turf fertilization program is nitrogen. The concept of late-season turf fertilization appears to be quite compatible with typical recommendations for tree and shrub fertilization. Application in mid-November (or whenever the plant is completely dormant) is recommended for plants in clay or clay-loam soils. Spring application (before bud break) is best for plants growing in sandy or loam soils. When Kentucky bluegrass is the predominant turf species, you should apply fertilizer at rates that provide a total of 4 to 6 pounds of nitrogen per 1,000 square feet per year. Three pounds of nitrogen per 1,000 square feet per year should maintain healthy trees. Trees that appear to be in poor health due to low fertility levels may require up to 6 pounds per year. Problems may arise, however, if turf and woody ornamental fertilization is performed at separate times or by different parties. In such a situation, as much as 6-12 pounds of nitrogen per 1,000 square feet per year could be applies to the turf beneath a tree -- if the fertilizer meant for the tree is broadcast over the turf. Excessive, unsightly turf growth, and possibly even turf damage, may result.

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