Few trees equal the beauty and provide the graceful forms, textures and color throughout the seasons as maples. They're great for providing shade and their large size adds tremendous benefits to the environment, wildlife and the value of your property. When planted right and cared for properly, maples are long-lived and exceptionally easy to grow and maintain.
Here's a breakdown of what you need to know regarding feeding, watering and pruning maple trees...
Please Note: If you are growing a Japanese Maple follow these links for care instructions...
Evaluate Soil Conditions
Though not absolutely necessary to do, before fertilizing your maple tree the best starting point is a soil test. Soil tests are done to determine soil pH and essential nutrient levels. Your local Extension Service might provide soil testing services or you can test soil yourself with a soil testing kit or soil pH testing probe.
TIP: Keep in mind that construction and many other factors often result in soils that differ from one landscape to the next, and even from one area or spot to another in a landscape. In other words, the soil in your front yard may be much different than the soil in your backyard. When growing such a magnificent, long-lived tree as a maple, to get the best long-term results it's always a good idea to test the soil in the area you intend to plant one.
Soil pH is Important!
Soil pH is a measurement of the alkalinity or acidity of soil and is measured on a scale of 1-14, with 7 as the neutral mark. Any measurement below 7 indicates acid soil conditions, and anything above 7 indicates alkaline.
Maples prefer an acid to neutral soil ranging from 5.0 to 7.0 on the pH scale. Once you know the soil pH, if necessary, you can adjust it to meet the needs of your maple.
Testing Soil pH
If you're unsure about the pH of your soil, and whether or not it's suitable for growing maples, it's a good idea to test the soil pH in the planting area. You can quickly test soil pH with a inexpensive soil test kit or pH tester probe.
To raise the pH (make more alkaline) you can add pelletized limestone to the soil. To lower the pH (make more acid) you can apply Soil Sulfur, Aluminum Sulfate, or Chelated Iron. Adding organic compost to the soil or using compost as mulch can also help to increase acidity and maintain acid soil conditions.
Learn More: What is Soil pH and How To Adjust It?
Feeding A Maple Tree
Older, well-established maple trees typically don't require fertilization. Their expansive root system can usually obtain nutrients through the soil and from rainfall. Younger trees will benefit from fertilization, which helps them to establish a good root system.
When to fertilize a maple?
I fertilize my maple trees in early spring, after new leaves have just begun to emerge, but only if they were looking a little dingy during the previous growing season. If they were healthy looking, I usually skip it. That said, to conserve moisture throughout the growing season and suppress weed growth, I always apply a 1 to 2" layer of cured, shredded or chipped wood mulch or pine straw around the tree in spring. As the mulch decomposes it will add vital nutrients to the soil that your maple tree will appreciate.
Note: Avoid the use of freshly chipped wood for mulch until it has cured in a pile for at least 6 months, a year is better. Avoid placing or piling mulch directly against the base of your plant as this could cause the bark to rot.
What type of fertilizer?
When feeding a maple tree, I use a slow-release shrub and tree fertilizer at rates recommended on the product label. Alternatively, you can feed with mild, organic plant food. Avoid the use of 10-10-10 and other similar quick-release fertilizers.
As mentioned above, I always spread a 1- to 2-inch layer of cured, shredded wood mulch or pine straw around my maple trees every spring. As these organic mulches decompose they add nutrients to the soil your maple trees will appreciate.
How much fertilizer?
This will depend of course on the size of the tree you are fertilizing and the type of fertilizer. Regarding slow-release shrub and tree fertilizers, you'll find application instructions on the package label.
Note: Avoid the use of raw manures around your maple tree.
Where to spread the fertilizer?
The root system of a maple tree can grow 4 feet deep or more into the soil, but the majority of the feeder roots responsible for absorbing nutrients are in the top 12 to 18 inches of soil. Spreading fertilizer on the soil surface is sufficient to reach these feeder roots. Spread fertilizer evenly around each tree, beginning at least 1 foot from its trunk and beyond the drip line (branch perimeter) of the canopy. For every 5 feet in height of your tree spread the fertilizer 1 foot beyond the drip line.
Note: If the soil is compacted or subject to excessive water runoff, the fertilizer can be applied in a series of holes 6 to 8 inches deep in the same area with about five holes per 1 inch of trunk diameter.
Watering A Maple Tree
Most maple trees prefer a moist but well-drained soil. That said, some like or will tolerate constantly soggy soils. It's good to know the moisture needs of the specific maple variety you intend on planting. You'll find soil type and moisture preferences on every plant page in the Wilson Bros Gardens website. Proper watering is especially crucial during the first year or two as the trees are working to establish themselves in the landscape.
Here's some watering tips:
Summer Watering
At planting time
Water deeply at planting time, making sure the soil around the root ball is moist all the way down to its base. Then, each day thereafter, check the soil moisture and only provide water if the soil has dried out somewhat or is just lightly damp. After several days of checking soil moisture you should establish how many days you can wait between waterings. Now you'll have a watering schedule. If there's a good soaking rain you can count this as a watering.
During the first growing season
After planting a new maple tree in the ground, especially during the hotter summer months, the tendency is to think it has to be watered every day in order to grow roots and become established in its new home. However, in average garden soil you should not have to water your newly planted maple every day. More often than not, this causes soggy soil conditions that can lead to root rot on some maple varieties. In the absence of sufficient rainfall, water only as needed to keep the rootball and surrounding soil damp to moist. Keep in mind that deep soaking less frequently is much better than splashing just a little water around the tree every day. Deep soaking promotes deep root growth and can reduce water loss by evaporation.
Note: If the leaves of your maple are browning on the tips, or wilting, this can be the effect of either dry or over-saturated soil. So, before watering, make sure to check soil moisture using the finger test or a moisture meter. If the soil is moist wait to water.
Thereafter
When well-established, which is usually a period of two years, or two spring seasons, most maples tree varieties won't require as much attention to soil moisture and watering. That said, in the absence of rainfall, especially during the warm season when plants are actively growing, maples may need supplemental water. During a drought, wilting leaves are usually a sign that your tree could use a good deep soaking. To be on the safe side, always use the finger test or a moisture meter check soil moisture before watering.
Winter Watering
Maple trees planted during the cooler winter months, when trees are dormant and without foliage, won't require as much attention to watering. Provide water only if necessary to keep the soil damp.
At planting time
When planted during the winter, maple trees are dormant and without leaves. Still, at planting time you'll want to soak the soil deeply after planting. Then check the soil moisture every few days until you've determined how many days or weeks go by until the soil has dried and water is needed. With average rainfall you may not need to water trees again until spring.
Note: If you have an automated irrigation system it's best to cut it off during the winter, only running it manually on occasion and only when and if necessary. Provide water during the winter only if there's been a prolonged period of dry weather.
Pruning A Maple Tree
Maple trees tend to "bleed" (lose sap) a lot when cut, which scares some people away from ever pruning them. A maple tree will grow fine without ever being pruned, however, pruning, especially young trees, can help to create a more dense and attractive canopy that provides better shade and visual appeal. That said, some folks prefer the natural look. If so, avoid pruning.
If you choose to prune your maple trees, here's some tips and instructions...
When To Prune A Maple Tree
Maple trees can be pruned in late winter or early spring, however this can cause excessive bleeding. This sap loss usually won't harm older, established trees but can cause damage to young trees. Therefore, any major pruning of a maple tree is best performed during summer, when all the leaf buds have already opened. At this time, pruning won't cause sap to leak from pruning cuts.
Note: Damaged or dead branches or stems should be removed when they occur. Make your cut beyond the point of breakage or dead part.
How To Prune A Maple Tree
There are a couple different reason why people prune a maple tree. One is a light pruning for shaping purposes or to maintain a tree form, and the other a heavier pruning for branch structure improvement.
CAUTION: It's my opinion that maple trees should never be topped. Removing or cutting through the central leader branch, or main top branches, will destroy the natural shape and structure of the tree.
Light Pruning
Light pruning to maintain a tree form is best done on younger trees, before their branches grow too large. It simply involves removing lower branches growing from the trunk to a desired height. See diagram below for where to make cuts on larger branches. I remove lower branches to a height so that folks can walk under the tree. That said, before removing a branch take time to study where it goes. Make sure that its removal won't spoil the shape of the canopy. Depending on the size of a branch, you'll use bypass hand pruners, lopping pruners, or a tree saw to remove branches.
Small stray stems spoiling the shape of the canopy, or stems on low hanging branches can be removed simply by using a pair of bypass hand pruners or lopping pruners to cut them off at desired length. It's best to make cuts just beyond a present leaf or leaf bud on the stem.
Stems on low hanging branches can be removed at any time of year simply by using a pair of bypass hand pruners or lopping pruners to cut them off at desired height.
Heavy Pruning
When removing a large branch from a tree, prune limbs just outside the base of the branch at a point called the "branch-bark ridge," as indicated in the diagram below. The branch-bark ridge is where the growing, expanding branch and the expanding trunk push up bark between them, looking like caulk, so to speak. If the bark ridge is squeezed up and out of the crotch, there is a corky or a raised ridge. Sometimes the bark is not squeezed up and out of the crotch; the expanding branch and trunk have grown around it and "included" it. The bark ridge is a crack or slit in this case.
On the bottom side of every branch where it meets the trunk or another main branch of the tree is the "branch collar," as indicated in the diagram above. Make sure your cut is beyond the branch collar, and the branch ridge at the top of the limb. Avoid cutting into branch ridge or branch collar!
Do not use wound paint or tar after making a cut. Trees will heal themselves.
Tip: If you have any reservations about pruning your shade tree call your a local arborist. (Heavily advised). Pruning mature trees may require special equipment, training, and expertise. If the pruning work requires climbing, the use of a chain or hand saw, or the removal of large limbs, then using personal safety equipment, such as protective eyewear and hearing protection, is a must. Arborists can provide a variety of services to assist in performing the job safely and reducing risk of personal injury and damage to your property. They are also able to determine which type of pruning is necessary to maintain or improve the health, appearance, and safety of your trees.