Having beautiful and healthy trees is a great way to add value to your home. When you properly care for and maintain your trees, with things like regular maintenance, including but not limited to watering, pruning, and fertilizing you can have magnificent trees. Even if you believe you have good soil conditions, adding a little fertilizer can help a lot. Our team at Five Star Tree Services want to go over all you need to know about fertilizing trees!
Fertilizing Trees
Many people misapply and misinterpret fertilizer as they consider it to be “food” for their trees. However, this is not actually what fertilizer is. It is the building blocks that help photosynthesis and growth. Photosynthesis is the process in which a plant turns water and sunlight into sugars. These sugars are what nourish plants. Fertilizer provides nutrients and minerals. If the soil is absent of minerals, this is where fertilizer comes in, to replenish the soil supply. When fertilizing, keep these things in mind; use in the correct amounts, at the right time, and in the right areas; and only use it when needed.
How To Determine if You Need to Fertilize
Test the soil: when you do this, it analyzes how acidic the soil is, or the alkalinity (pH), and the levels of nutrients present. Depending on the test results, this will help determine if you need fertilizer and of what nutrient content.
Poor growth: if you can visibly see that your plants/trees are struggling and there has been little to no growth, this is a good indicator that fertilizer is necessary. Some symptoms to watch out for include things like pale green or yellow leaves, smaller leaves than usual, premature leaf loss and autumn colouration, limited twig development, or twig/branch dieback. We do want to note that these symptoms are not always a 100% indicator that there is a lack of nutrients in the soil. Making it so that fertilizer wouldn’t solve the problem. A soil test would be necessary to 100% determine the nutrient levels properly. You can also see these symptoms from things like compact soil, pests, disease, weed stress, and severe climate conditions. Before fertilizing, always figure out the true cause of the symptoms.
New trees & transplanted trees: these trees will need a little extra boost when planted. Using fertilizer in the early years will help the development of tree canopies. For all newly planted trees, slow-release fertilizers are the most optimal and effective.
Lawn treatments: if you regularly get your lawn treated with fertilizer, you won’t need to fertilize your trees. The grass fertilizer will absorb into the soil and help your tree roots as well.
Planting bed trees: these trees, which are grown in planting beds, will require fertilizer. Especially if you have sandy soil, which has little to no organic matter.
Slow Release and Fast Release Fertilizer
You can find two types of fertilizer: slow release and fast release.
Slow release (controlled release): this is when nitrogen is slowly released into the soil over time. They are usually the more expensive options compared to water-soluble or fast release fertilizers. These fertilizers can contain sulfur-coated nitrogen or IBDU or urea formaldehyde. Half the nitrogen should be water-insoluble or slow-release nitrogen. This is a great fertilizer choice for newly planted trees or where runoff happens, like in compact soils or slopes. Since nutrients are supplied over an extended period of time and gradually, fertilizer damage (burning) and water pollution are a lot lower.
Fast release: drains quickly through the soil. Nitrogen is water soluble allowing it to be rapidly available to the plants.
Natural fertilizers: these are things like compost, cow manure, or complete fertilizer mixes. They gradually release nitrogen and other nutrients. An advantage to these is that they provide minor nutrients, in modest amounts, such as iron or zinc, that you can’t find in synthetic fertilizers. Additionally, they also help enhance soil structure. One drawback to this type of fertilizer is that they tend to have lower concentrations of nitrogen, phosphorus, and potassium. This results in more fertilizer needing to be applied in order to get the same amount of nutrients as synthetic products.
How To Apply Fertilizer
There are two main ways to fertilize your trees: indirectly or directly. Regardless of which technique you use, they both require applying fertilizer to the whole root zone. Due to the soil surface having high oxygen concentrations, most primary feeding roots are going to be about 10-14 inches deep in the soil. This means that if you apply your fertilizer, it will need water to get it to the roots. You should water immediately after fertilizing to get it off of leaves and saturate into the soil quickly. If you do not water right after fertilizing, you will lose some nitrogen to evaporation.
Direct fertilization: this is when you intentionally fertilize your trees. An efficient and cheap way to fertilize your trees is with broadcasting. This is when you spread the directed amount of fertilizer over the root zone with a spreader. For optimum coverage, halve the total amount of fertilizer to be applied. Apply one half of the total amount in one direction, then take the remaining half and apply it perpendicular to the first. Make sure all leaves are dry.
Indirect fertilization: this is when your trees are not the primary recipient of fertilizer, your grass is. Which indirectly fertilizes your trees along with it.
How Five Star Tree Services Can Help
Fertilizing is important and can really help your trees thrive. If you need help with your tree care in Toronto, our team from Five Star Tree Services can help! Give us a call at (416) 990-3355 today!