Micro-injection constitutes the direct injection of necessary nutrients into the trunk of the tree or bush. It's an acceptable commercial use for remedying or invigorating trees demonstrating stress or decline symptoms. Nutrients can as well be solidified into gelatin capsules and imbedded in holes in the trunk. Micro-injection research is comparatively limited and outcomes are often conflicting. Boring holes, imbedding or injecting fertilizer and sealing holes could lead to trunk disfigurement and decay. Foliar applications, injections or implants would better be used only when soil application of fertilizer is unrealistic. These routines are regarded as short-term remedies for nutrient deficiencies and pest infestations. In the final analysis, suitable soil and foliar applications must be applied for a permanent cure.

Fertilizer Placement
Fertilizer should not be concentrated around the base or trunk of a tree or shrub, but should be applied over as much of the plant's root zone as possible. For trees and shrubs, fertilizer should be applied over an area twice as large as the crown spread. Since most landscape plant roots grow in the top foot of soil, surface, but not deep application, is recommended.

Factors Affecting Fertilizer Uptake
Numerous elements impact how easily and well trees and bushes assimilate fertilizers. The most significant uptake factors are:
1.Fertilizer variant (inorganic, quick release, or fluid forms are assimilated faster than organic, slow-release, or dry forms)
2.Soil type (clay particles and organic matter assimilate or bind more nutrients than sand, so fertilizer needs to be applied more frequently in sandy soils, but with lesser rates each time due to leaching potential)
3.Soil moisture content and soil temperature (nutrient uptake is faster in moist warm soils)
4.Plant vigor (plants under stress are more ineffective in assimilating available nutrients because of damaged or decreased root systems)

Application Timing
Fertilizer should be given when plants require it, when it will be most effective, and when plants can readily take it up. Late summer and early fall fertilization may rouse new growth that is not winter hardy, and summer drought may interfere with nutrient uptake, but spring, fall, and winter applications are acceptable. A split application may be beneficial, applying half the yearly rate in early spring and the rest in the fall as or after plants go dormant.

If water is unavailable, do not fertilize at all - plants will be unable to take up the nutrients. (During a dry season, fertigation - application of fertilizer through an irrigation system can be valuable.)

Tree and bush fertilization comprises only one part of aggregate plant maintenance. Fertilization might not benefit a plant if it's under stress from inadequate soil aeration or drainage, sodden soil, deficient light or space, or excessive pest problems. Altogether factors determining plant growth should be kept at optimal levels to guarantee plant vigor.

Related posts:

1. Fertilizing Landscape Trees and Shrubs Part 3
2. Fertilizing Landscape Trees and Shrubs part 1
3. Fertilizing Landscape Trees and Shrubs Part 2

Methods of Application
Fertilizers may be put on either directly or indirectly for trees and shrubs. When sod is fertilized, tree and bush roots that stretch into the sod area absorb some of the fertilizer, and are consequently indirectly fertilized. Sod fertilization rates should be supplemented only if trees and bushes are demonstrating symptoms of nutritive deficiency.

Direct application of fertilizer may involve incorporation into the backfill soil or placement in the planting hole at planting time. However, the most common form of direct fertilizer application, broadcasting, is generally the most effective, especially relative to cost. Simply broadcasting the desired fertilizer over the soil atop the tree and shrub roots and watering it in is usually adequate. Compacted soil should first be aerated or raked.

The most sensible and efficient way to fertilize large trees is to scatter granular fertilizer on the surface of the soil and allow rain or irrigation water to transport the nutrients to the roots. Evenly broadcast the fertilizer over the area to be fertilized - that area covering the outer two-thirds of the distance between the trunk and the drip line and extending at least 50 percent of the crown radius beyond the dripline.

NOTE: Definition: The dripline is the area directly located under the outer circumference of the tree branches. This is where the tiny rootlets are located that take up water for the tree. Trees should be watered here, not by the base of the trunk, or the tree may develop root rot.

An alternative method is to position granular fertilizer into holes in the ground that are four to twelve inches deep. These holes are constructed in a regular pattern at 2- to 3-foot separations, in the same expanse as broadcast fertilizer is applied. Divvy up the fertilizer amongst the holes. This process does not insure homogeneous coverage to all feeder roots, particularly in the upper few inches of the soil surface where the bulk of the roots occur. Strong concentrations of fertilizers in these holes can in addition injure roots located next to the hole.

A commonly used commercial method is to inject liquid fertilizers into the soil. A special injection rod is used and the fertilizer solution is injected under pressure. A comparable probe mechanism called a 'root feeder' is sold at most garden centers. The long probe attaches to a garden hose and water-soluble fertilizer cartridges distribute nutrients and water directly into the tree root zone. The tip of the injection needle should be inserted 4 to 12 inches into the soil at 2- to 3-foot intervals. Fertilizers suitable for liquid injection are typically more expensive per unit of nutrient and are frequently more difficult to apply than granular fertilizers.

Spikes are another alternative for tree or shrub fertilization. These are pounded into the soil with a heavy hammer and can only be used successfully when the soil is moist. The spikes do not evenly distribute fertilizer around the tree's or shrub's major feeder roots. These spikes are an expensive alternative. Their reputation is based on simplicity and ease of application.

Foliar feeding is a quick-fix solution when a nutrient deficiency has been found. The leaves, buds and green wood are capable of a little nutrient absorption. Foliar nutrient sprays are applied with a pressure sprayer or siphon sprayer attached to a garden hose. The greening from foliar spraying is fairly quick but not long lasting. More often than not deficiencies of micronutrients including iron, boron or manganese are corrected by seasonal foliar applications.

Related posts:

1. Fertilizing Landscape Trees and Shrubs Part 4
2. Fertilizing Landscape Trees and Shrubs part 1
3. Fertilizing Landscape Trees and Shrubs Part 2

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, 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 typically depleted soil nutrient, furnishes the greatest growth response. Unfortunately, soil tests or analyses for accessible nitrogen are not very dependable. Nitrogen is present in different forms (e.g. nitrate, ammonium, urea) and these forms can alter rapidly in the soil. All the same, overall tree growth, especially root and shoot elongation, leaf color and leaf size, can be heightened with increases of nitrogen. Be sure not to over fertilize with nitrogen. Don't overcompensate with greater amounts of nitrogen when fertilizing grass, bushes and trees. Nitrate leaches readily from numerous soils and can create water pollution problems.

Fertilizer Selection
An assortment of fertilizer types exist:
Complete (N-P-K) vs. Partial (one or additional select nutrients)
Organic vs. inorganic
Fast release vs. slow release
Dry (grained, pelletized, spikes, powdered, encapsulated) vs. liquid

To help determine the type of fertilizer to apply, consider the following: type of plant, time of year, desired rate of plant reaction, application methods and equipment cost, proximity to water sources, effect of soil type and pH, type of deficiency, and results of a soil test or other sampling method.

Nearly all landscape plants profit from a slow secreting nitrogen fertilizer that can be organic or inorganic. Remember that nitrogen is easily washed through the soil, but phosphorus and potassium are not, signifying they necessitate less frequent application.

NOTE: The fertilizer package has three numbers such as, 10-10-10. They represent, respectively, the percentage by weight of nitrogen (N), available phosphorus (P2O5) and water-soluble potash (K2O). These figures help you choose the right fertilizer and determine how much to apply. For example, a fertilizer labeled as 10-10-10 contains 10 percent N, 10 percent P2O5 and 10 percent K2O. The remaining 70 percent is usually inert filler.

Related posts:

1. Fertilizing Landscape Trees and Shrubs part 1
2. Fertilizing Landscape Trees and Shrubs Part 4
3. Fertilizing Landscape Trees and Shrubs Part 3