Fertilize Your Landscape Properly Part 1

Maintenance plans should be produced for trees and shrubs in your landscape. A effective care program includes monitoring and keeping insect and disease problems in line along with restraining weed competition, and giving well timed 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 bushes in residential and commercial landscape plantings are frequently fertilized to keep them flourishing and attractive. Over-fertilization is frequent, inducing excessive growth, particularly in immature nursery stock. Trees growing in lawn expanses usually get some nutrients when the grass is fertilized. This is normally adequate to maintain most trees in prolific soil. However, fertilization could be required on altered soils wherever unconsolidated fill material has been superimposed or the topsoil has been removed. Managed urban areas where fallen leaves are dispatched may also call for a fertilization program 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.

Fertilizer Objectives

How and when to fertilize landscape trees and shrubs depends on:
Maintenance objectives (stimulate new vs. maintain existing growth)
Tree and shrub ages (generally more for younger and less for older plants)
Plant stress 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.

Newly Planted Trees Fertilizer Use

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.

How to Determine Whether to Fertilize

Visual inspection of trees and shrubs is often the best overall factor to use in making fertilization decisions.
Look for:
Poor leaf color (pale green to yellow)
Reduced leaf size and retention
Premature fall coloration and leaf drop

Soil Test

Eighteen nutrients are essential for plants:carbon,oxygen, hydrogen, nitrogen, phosphorus, potassium , calcium, magnesium, sulfur and nine trace minerals: iron , boron, copper, manganese, molybdenum, zinc, cobalt, nickel and chlorine. Carbon, oxygen and hydrogen function in the formation of plant cells and food creation, the first two obtained from the atmosphere and the latter gotten from water absorbed by roots.

A soil test furnishes specialized data on the potential for plant reaction to agricultural limestone and to phosphorus and potassium fertilizers. In addition it provides a verifiable basis for ascertaining how much of those elements to add once they are found to be lacking. A representative soil sampling can be a challenge to get, because most nutrient-absorbing roots of trees and bushes are in the upper six inches of the soil and may stretch out two or three times beyond the radius of the crown. Consequently, in determining the nutritional demands of trees and shrubs, it's also essential to look at soil and moisture conditions; the species, age and vigor of the plants; and previous fertilization.

Nitrogen, the most frequently deficient soil nutrient, provides the greatest growth reaction. Regrettably, soil tests or analysis for available nitrogen are not very reliable. Nitrogen is at hand in several forms (e.g. nitrate, ammonium, urea) and these forms can change rapidly in the soil. However, overall tree growth, particularly root and shoot elongation, leaf color and leaf size, can be enhanced with additions of nitrogen. Be careful not to over-fertilize with nitrogen. Do not overcompensate with higher amounts of nitrogen when fertilizing grass, shrubs and trees. Nitrate leaches readily from many soils and can cause water pollution troubles.