Posts tagged Trees

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 important in urban and suburban areas of the nation where soils have been altered due to construction. These urbanised soils tend to be heavily compacted, badly aerated, poorly drained, and low in organic matter. Even where land has not been affected, fertilization may be needed as part of a maintenance program to step-up plant vigor or to improve root or top 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. Fertilizer is no stand-in for environmental factors, such as sunlight and water, which must be in balance if a tree or shrub is to grow into its full potential. Trees and shrubs that are healthy and growing robustly are less susceptible to attack by insects and diseases. An application of fertilizer may, in some instances, improve the plant’s resistance to further infestations of certain pests. For example, maple trees will recover from mild cases of Verticillium wilt following applications of nitrogen fertilizer. Objectives for FertilizingHow 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 levelsWhen to FertilizeThe best time to fertilize trees goes from late autumn, after the leaves have come down, through the winter and into early spring before new growth comes about. Fertilizer employed in the autumn has a lengthier period of time to infiltrate the soil enabling the roots to more efficiently assimilate it. The fertilizer is soaked up by the roots during the winter and is accessible to the plant for growth in the spring. Trees that are rapidly developing should be fertilized annually. Well-established, adult trees usually call for fertilizer once every three to four years. Newly Planted Trees Fertilizer UseNewly planted trees usually do not need fertilizer during the first growing season. Most transplanted trees developed in the nursery have high levels of nutrients that last through the first growing season. Too much fertilization during the first year can damage the tree and reduce its rate of growth. After the first year, nitrogen can be applied in an approximately 3ft area around each tree. This will ensure a sufficient supply for continued growth. Do not apply fertilizer within 12 inches of the stem of the tree because fertilizer can burn and harm young stem tissue. How to Determine Whether to FertilizeVisual 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 dropSoil TestEighteen 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 specialised 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 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 overfertilize 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. Selecting a FertilizerAn 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. liquidTo assist in determining the form of fertilizer to utilize, weigh these factors: type of flora, season, wanted rate of plant reaction, application program and equipment price, proximity to water sources, consequence of soil type and pH, type of deficiency, and outcomes of a soil test or additional sampling methods. 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. Methods of ApplicationFertilizers may be put on either directly or indirectly for plants. 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. Straight application of fertilizer could call for placement into the backfill soil or positioning in the planting hole at planting time. Nevertheless, the more common variant of direct fertilizer application, broadcasting, is typically the most useful, especially proportional to cost. Just broadcasting the fertilizer over the soil atop the tree and bush roots and watering it in is generally enough. Compressed 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. 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 separationsl, 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 rootsl, 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 additional choice for tree or bush fertilization. These are rammed into the soil with a heavy hammer and can only be employed effectively when the soil is damp. The spikes don’t evenly broadcast fertilizer around the tree’s or bush’s major feeder roots. Tree spikes are a pricey choice. Their popularity is founded on simplicity and ease of application. Foliar feeding is a short-run answer when a nutrient inadequacy has been diagnosed. The leavesl, buds and green wood are able to absorb some nutrients. Foliar nutrient sprays are put on with a pressure sprayer or siphon sprayer attached to a garden hose. The green-up from foliar spraying is fairly speedy but not long enduring. Generally deficiencies of micronutrients including ironl, boron or manganese are rectified by seasonal foliar applications. Micro-injection is the straight injection of essential nutrients into the trunk of the tree or shrub. It is a customary commercial practice for relieving or invigorating trees showing stress or decline symptoms. Nutrients can also be placed in gelatin capsules and set in in holes in the tree trunk. Micro-injection research is relatively limited and results are often conflicting. Drilling holes, implanting or injecting fertilizer and sealing holes can lead to trunk disfiguration and decay. Foliar applications, injections or implants should only be considered when soil application of fertilizer is not viable. These measures are considered short-term cures for nutrient deficiencies and pest infestations. Ultimately, the proper soil and foliar applications must be engaged for a long-term cure. Placement of FertilizerFertilizer 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 soi[l/c] surface, but not deep application, is recommended. How Fertilizer Uptake is AffectedMany factors affect how well and well trees and shrubs absorb fertilizers. The most important uptake factors are:Fertilizer form (inorganic, fast release, or liquid forms are absorbed faster than organic, slow-release,or dry forms)Soil type (clay particles and organic matter soak up or bind more nutrients than sand, so fertilizer application needs to be more often in sandy soils, but with lower rates each time due to leaching potential)Soil moisture content and soil warmth (nutrient uptake is faster in moist warm soils)Plant vitality (plants under stress are less able to take up available nutrients due to damaged or reduced root systems)Application TimingFertilizer 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 shrub fertilization is only one ingredient of total plant maintenance. Fertilization may not assist a plant if it is under stress from poor soil aeration or drainage, saturated soil, inadequate light or space, or excessive pest problems. All factors influencing plant growth should be kept at optimal levels to ensure plant vigor.