Maple trees are known for their beautiful fall foliage and for providing shade in the backyard. This American icon is relatively easy to grow and care for, but choosing the right time to fertilize is important to your maple tree’s health!
The best time to fertilize an established maple tree is in early spring before the buds break or late fall after the leaves have already dropped. When first planting a maple tree, fertilizer should not be used until the tree becomes established. Slow-release fertilizers are the best type to use.
Even though established maple trees do okay on their own, an application of fertilizer can help them thrive. Below, we’ll go over when to fertilize your maple tree and which fertilizers to use!
Do Maple Trees Like Fertilizer?
Before we get into when to fertilize your maple tree, let’s establish if you even need to fertilize it!
Maple trees can grow in a variety of conditions, soil types, pH levels, and hardiness zones. There are over a hundred different species, some ranging from just 8 feet tall to over 100 feet tall.
Despite this vast diversity, all maple trees have a few things in common when it comes to fertilizer.
Established Maples Don’t Need Too Much Fertilizer
When first planting a maple tree, the little seedling has a tough few years ahead of it. It must adjust to the new soil type, grow roots to anchor the tree, and gather enough nutrients to start growing.
Established maples don’t have this problem and can focus more on vertical canopy growth rather than root growth.
Once a maple tree is established, it doesn’t need much to survive. Usually, the nutrients in the native soil will be enough to keep your maple tree healthy.
That being said, if you want your maple tree to grow at its absolute fastest growth rate, a dose of fertilizer can help. Fertilizers that contain nitrogen will encourage your maple tree to grow taller and produce more leaves, giving your maple a fuller appearance.
If your maple tree seems to be growing slower than it should be, it might need a dose of nitrogen-containing fertilizer along with probably a TON of water.
Newly Planted Maple Trees Do Not Need Fertilizer
Planting a new tree is always an exciting time. You stand back and just imagine all the shade and fall foliage you’ll get to benefit from when the tree is fully grown.
While exciting, planting a new tree can also be a bit tricky. You may be tempted to provide your new maple tree with fertilizer to help it grow, but this can do more harm than good.
In general, fertilizers encourage the tree to grow new shoots and leaves, but it does not encourage root growth very much.
When maple trees are first getting established, they need to focus on root growth instead of shoot growth.
It can be especially tempting to fertilize new maple trees that don’t seem to be growing fast. Don’t worry, this is totally normal! When maples focus on root growth, they will have a slower growth rate.
According to an article in the Journal of Arboriculture & Urban Forestry, fertilizing newly planted red maples does not speed up establishment periods, increase trunk growth, or increase shoot growth.
If you’d like to learn more, take a look at our maple tree timeline to see how long it takes for full growth.
Fertilizing Can Be Beneficial
Just because maple trees can survive without fertilizer doesn’t mean they will thrive. Fertilizer can be beneficial for maple trees for a few different reasons:
- Iron deficiency: Maples, in particular, have trouble getting enough iron from high-pH soils. In this case, an iron fertilizer can help spruce your maple right up!
Southern Ag’s Chelated Liquid Iron comes in a 16-ounce container. The liquid must be diluted with water and then can be applied around the maple tree’s drip line or applied directly to any yellowing leaves.
- Faster growth: If you want to encourage your maple tree to grow faster, fertilizers can help give your tree enough nutrients to speed up its growth rate.
- General maintenance: Even if your maple tree is not experiencing any nutrient deficiencies, a regular application of fertilizer can improve the overall health of your tree, making it more resistant to pests and other unwanted ailments.
How Often Should I Fertilize My Maple Tree?
Fertilizers provide maple trees with the nutrients they need to grow and thrive, but fertilizing at the wrong time can be harmful to maples and have unwanted consequences.
Let’s take a closer look at the best time to fertilize your maple tree and how often to do it.
Fertilize Your Maple Tree Annually
Some trees (such as citrus fruit trees) need fertilized multiple times a year. Maple trees are a little different and will benefit from just a single yearly application of fertilizer.
Fertilizing more than once a year can overburden the roots of your maple tree, giving them more nutrients than they could use. This can cause root burn. Some of the symptoms of root burn include:
- Stunted growth
- Brown coloration on edge of leaves
- Discolored roots
A single application of fertilizer will benefit most maple trees. Following the directions on the label can help you avoid giving too little or too much fertilizer to your tree.
According to Colorado State University, slow-release fertilizers are better than water-soluble fertilizers for shade trees such as maples.
If you find fertilizing isn’t helping your maple tree, then you may have a reason to cut it down.
Some Maples Need Fertilization Twice A Year
We mentioned before that most established maple trees do not need a ton of fertilizer. However, there are some instances where maples may need fertilizing twice a year.
The main reason you would fertilize your maple tree twice a year is if there is a nutrient deficiency in the soil where it is planted.
You can perform a soil test to see what kind of nutrients are lacking in your backyard’s soil. Alternatively, you can wait and see what kind of symptoms pop up on your maple tree before deciding to apply fertilizer once or twice a year.
Some of the symptoms that your maple tree is nutrient deficient include:
- Stunted growth
- Distorted, discolored, or small leaves
- Early leaf drop
- Yellowing leaves
- Brittle branches or leaves
It’s more important to catch these symptoms on young trees than on old ones, but even older trees can benefit from fertilizer when they are showing signs of stress.
Fertilize Your Maple When All The Leaves Have Fallen
Some maples may need to be fertilized twice a year while others may not need any fertilizer. If you decide to fertilize your maple, you’ll want to make sure to do it at the right time.
One of the best times to fertilize your maple tree is in the late fall after all the leaves have fallen off.
It’s important to wait until the leaves have fallen. Fertilizing before this will prevent your maple tree from hardening off for the winter. Applying fertilizer after the maple has been prepared for winter will allow the roots to absorb and then store the nutrients for use during the winter.
Fertilize Before Periods Of Rapid Growth
Spring is a time when everything is waking back up for the year. New shoots, buds, and flowers are forming and the surrounding landscape finally looks alive again!
If you decide to fertilize your maple tree in the spring, you’ll want to fertilize well before any buds break open.
It’s recommended to fertilize in early spring to give your maple tree the nutrients it needs to form flowers and continue to grow.
You should avoid fertilizing your maple tree in late spring, summer, and early fall.
What Are The Best Maple Tree Fertilizers?
Nitrogen is one of the most important nutrients when it comes to maple trees, but not all nitrogen is the same when it comes to fertilizers.
Slow Release Organic Fertilizers Work Great
There are two broad categories of fertilizers available—slow-release and quick-release. One is water-soluble (quick release) while the other is not water-soluble (slow release).
Quick-release fertilizers may sound better because the nutrients are immediately available, but these types of fertilizers aren’t great for trees like maples that do not require a lot of fertilizer.
Instead of quick-releasing water-soluble fertilizers, you’ll want a slow-release fertilizer such as Milorganite 32 lb. Slow-Release Nitrogen Fertilizer. It comes as granules that can be spread on the soil around your maple tree.
No matter which fertilizer you choose, it’s important to make sure your maple tree has enough water to dilute the nutrients. Learn more about why maple trees need so much water (and when to water them).
Fertilizer Spikes Work Well Too
Fertilizer spikes aren’t any different than normal fertilizer except for how you deliver the fertilizer to your maple tree. While many fertilizers come as granules, spikes are driven into the ground.
Jobe’s Fertilizer Spikes comes with 15 spikes and has an NPK ratio of 16-4-4 (16% nitrogen, 4% phosphorous, 4% potassium).
Spikes are an excellent choice for a maple tree fertilizer because they release nutrients slowly and they’re good for the environment. Spikes are far less likely to enter stormwater runoff than granular fertilizers.
You can read more here about the best maple tree fertilizers and how to use them.
That’s A Wrap!
Maple trees might be bumping elbows with dogwood and oaks for the #1 spot for backyard trees. They provide shade and plenty of interesting colors in the fall.
In general, maple trees do not require a lot of fertilizer to stay healthy. However, an annual application can benefit some maples.
The best times to fertilize your maple tree include early spring, about 5 weeks before buds break, or late fall after the leaves have fallen off the tree.
Some maple trees may need applications both in the spring and the fall, but most only need one per year.
Maple trees will benefit more from slow-release fertilizers or spikes than water-soluble fertilizers. You can always contact your local arborist to get a better idea of what kind of fertilizer you should be using and how often to use it.
If you’re considering planting a new maple tree, take a peak at our list of the best maple trees to plant!
Day, S. D., & Harris, J. R. (2007). Fertilization of Red Maple (Acer rubrum) and littleleaf Linden (Tilia cordata) Trees at Recommended Rates Does Not Aid Tree Establishment. Arboriculture & Urban Forestry, 33(2), 113-121.
Lee, JS. Relationship of root biomass and soil respiration in a stand of deciduous broadleaved trees—a case study in a maple tree. j ecology environ 42, 19 (2018).
R A Lautenschlager, John H Pedlar, John A Winters, and Cathy M Nielsen. Ice storm damage: Effects of competition and fertilization on the growth of sugar maple trees. The Forestry Chronicle. 79(1): 63-69.
Smith LJ, Stephan K. Nitrogen Fertilization, Stand Age, and Overstory Tree Species Impact the Herbaceous Layer in a Central Appalachian Hardwood Forest. Forests. 2021; 12(7):829.