Fertilizing Landscape Trees and Shrubs Part 1

Sustainment programs should be prepared for trees and shrubs on your landscape. A dependable sustainment plan includes checking and containing insect and disease problems, restraining weed competition, and doing timely applications of water, mulch, and fertilizer.

Tree and bush fertilization is particularly crucial in urban and suburban areas of the country where soils have been changed due to building. These urban lands incline to be heavily compressed, poorly oxygenated, poorly drained, and short of organic matter. Even where soils haven't been stricken, fertilization is possibly needed as part of a sustainment program to step-up plant vigor or to improve root or crest growth.

Trees and shrubs in residential and commercial landscape plantings are frequently fertilized to keep them healthy and attractive. Over-fertilization is prevalent, causing excessive growth, especially on young nursery stock. Trees growing in lawn areas usually receive some nutrients when the grass is fertilized. This is usually sufficient to maintain most trees in fertile soil. However, fertilization may be desirable on altered soils where unconsolidated fill material has been added or the topsoil has been removed. Managed urban areas where fallen leaves are taken off may also require a fertilization regime to enrich soil and replenish nutrients.

Plant nutrition is no stand-in for environmental factors, such as sunshine and water, which must be in equilibrium if a tree or bush is to acquire its full potential. Trees or bushes that are healthy and flourishing are more insusceptible to assault by insects and diseases. An application of fertilizer might, in a few cases, improve the plant's resistance to additional infestations of certain pests. For instance, maple trees will recoup from mild cases of Verticillium wilt after applications of nitrogen fertilizer.

Objectives for Fertilizing

How and when to fertilize landscape trees and bushes hinge upon:
Sustainment aims (induce new vs. maintain existing growth)
Tree and bush ages (in general more for newer and less for older plants)
Plant strain levels

Time to Fertilize

The top time to fertilize trees extends from late fall, after the leaves have fallen, through the winter and into early spring before vigorous new growth occurs. Fertilizer applied in the fall has a longer time period to penetrate the soil enabling the roots to more efficiently absorb it. The fertilizer is taken up by the roots during the winter and is available to the plant for growth in the spring.
Trees that are fast growing should be fertilized yearly. Well-established, mature trees usually require fertilizer once every three to four years.

Fertilizing Newly Planted Trees

Freshly planted trees typically do not need fertilizer during the 1st growing season. Almost all transplanted trees produced in the nursery have elevated levels of nutrients that last through the 1st growing season. Exuberant fertilization during the first year could harm the tree and cut back its rate of development. After the 1st year, nitrogen can be utilized in a roughly 3ft area around each tree. This will assure a satisfactory supply for continued development. Don't apply fertilizer within 12 inches of the stem of the tree since fertilizer can burn and injure young stem tissue.