How To Fertilize Your Tree
Your trees and shrubs are a valuable asset to your home and investment to enjoy for years to come. It is essential to ensure these living parts of your landscape receive the right nutrition at the right time to boost their health so that they can fight off diseases, pests, and environmental stressors. Even if your soil is rich, your trees may not receive the nutrients they need to remain healthy making tree fertilization an important part of your tree care program.
What Is Tree Fertilization?
Tree fertilization is applying a liquid or granular fertilizer to the soil surrounding your tree. The fertilizer contains macronutrients that are beneficial to your tree which it often cannot get from its surroundings on its own.
What Does Tree Fertilizer Do?
Trees actually make their own food through photosynthesis. However, the minerals and nutrients supplied by fertilizer aid your tree in the process of photosynthesis and stimulate health and growth. Fertilizers boost the health of your tree making it less prone to pest invasions and diseases.
Do Trees Need To Be Fertilized?
It is not uncommon for trees to need fertilization. Despite your best efforts to mimic their natural environment, fertilization may be necessary due to a loss of nutrients.
The age of your tree is an important factor, as young or newly transplanted trees benefit from fertilization as it speeds up top growth and helps them adjust to the environment.
Benefits of Tree Fertilization
Tree fertilization is beneficial when it is needed, in the right amount, at the right time. The benefits include:
- Promoting healthy growth.
- Healing and recovery from environmental stressors like pollution and seasonal changes.
- Maintaining long-term health.
- The ability to fight off pests and disease.
Types of Tree Fertilizers
There are three main types of tree fertilizers that work in different ways to meet the nutritional needs of your tree. The two most common are complete fertilizer and slow-release nitrogen. Tree fertilizers are identified by the product label which contains three numbers representing the percentages by weight of nitrogen, phosphate, and potash contained in the fertilizer. These macronutrients are vital to the health of your tree.
Complete Fertilizer
A complete fertilizer contains all three of the major plant nutrients, nitrogen, phosphorus, and potassium. Most tree fertilizers have a ratio of 3:1:1. You would use your soil test results to determine if complete fertilizer has the nutrients your tree needs due to deficiency.
Slow-Release Nitrogen
Slow-release nitrogen is a fertilizer that releases nitrogen slowly over a long period of time. It is usually more expensive than fast-release nitrogen, but less likely to contribute to nitrogen water pollution and allows your tree continuous nourishment. Many tree fertilizers are a combination of slow-release and fast-release nitrogen.
Compost and Organic Fertilizer
Compost is made of decaying organic matter and can be spread around the base of trees. However, you should be careful to put not more than a one-inch layer of compost around the base of your tree. Organic fertilizer, such as shredded leaves from your yard, can also be used as a fertilizer. The leaves decompose over time and slowly release nitrogen into the soil. However, these natural fertilizers often do not contain enough nitrogen to satisfy the nutritional needs of your tree and therefore must be replenished often.
How To Apply Fertilizer To A Tree
The way that fertilizer is applied is just as important as the kind of fertilizer that is used and the timing of the application. There are at least four main ways to apply fertilizer to a tree.
Surface Broadcasting
One of the easiest ways to apply fertilizer is through surface broadcasting. In this method, granular fertilizer is applied to the bare soil or mulch surrounding your tree. You would begin near the trunk and extend the fertilizer out to the drip line, or the ends of the branches. Next, you would be sure to irrigate the fertilizer or apply it right before it rains.
Deep Root Fertilization
Deep root fertilization is a common method used by commercial tree and landscape companies. With this method, liquid fertilizer is mixed with water and injected directly into the soil surrounding the tree. This method is generally more expensive than the granular surface broadcasting application method, but it yields fast results and gets more directly into the root systems of the tree.
Foliar Application
Foliar applications rely on the leaves of the tree to absorb and transport the nutrients. This fertilizer attaches to the end of a garden hose and is sprayed onto your tree. Trees that benefit the most from this application are smaller trees with limited foliage. This method is best done when the leaves are fully developed in the late spring or early summer. You must be careful not to overspray the leaves as it will burn them.
Can You Over-Fertilize Trees?
Yes, you can over-fertilize your trees which can lead to:
- Attracting insects such as aphids.
- Root damage or burning of your tree’s vital root systems.
- Nutrient pollution of groundwater systems or nearby rivers, ponds, or lakes.
Your trees can also be damaged by some combinations of weed killers and lawn fertilizers. Do not use broadleaf herbicides around your tree, as most deciduous trees are broadleaved. Instead, opt for pre-emergent herbicides, which are safe to use around trees.
Call The Professionals
Applying fertilization to your trees is a complicated process that requires testing your soil’s pH, the timing of specific application strategies, and selecting the best kind of fertilizer most beneficial to your tree. There is science and art to tree fertilization and it should not be taken lightly.
Contact the professionals at Winkler Tree and Lawn Care who know best how to protect these amazing living investments in your landscape. You need professional arborists who know the business of tree care and can customize a tree fertilization plan that is just right for you and your trees.
FAQ About Tree Fertilization
Tree fertilization can be a complicated process. There are many common questions about tree fertilization that many homeowners face.
When Should Trees Be Fertilized?
Trees can be fertilized in the fall, between late October and early December, or in the late winter and early spring, between late February and early April. You should never fertilize in the late summer or early fall as this will stimulate new growth when the trees are preparing for dormancy.
What Fertilizer Is Best For Trees?
Most experts recommend slow-release nitrogen fertilizer as the best for trees.
How Often Should Trees Be Fertilized?
Trees should be fertilized twice a year. However, it depends on the health of your trees, their location on your property, and other factors. An experienced tree care professional can provide a detailed customized fertilization schedule.
