Ornamental plants often need special care and help. This is because ornamental features require extra energy.
The best fertilizer for the Japanese Maple is a slow-release granular fertilizer with a nitrogen content of 10 to 15. Apply it in early spring and the Japanese Maple will be supplied with nutrients for the entire growing season.
This is a quick fertilizer recommendation and if you want to know more read this article to the end. Also, for those of you who are seriously interested in growing Japanese Maples, I highly recommend the article – Top Tips for Care of Acer Palmatum.
When to fertilize?
The best time to fertilize Japanese Maple is early spring when the buds have started to push. By using a slow-release fertilizer at this time, you can be sure that your tree will get its nutrients by the end of the growing season.
Most products like this have a release time of 3-6 months. Give preference to a product that lasts longer. That way you do not have to fertilize more this year.
If you use other types of fertilizer, you should strictly follow the recommendations on the label and make sure you consult your supplier.
Do not fertilize with slow-release pellets later than May. Otherwise, the tree may enter the winter in an active state and suffer frost damage. For the same reason, never fertilize in the fall or winter.
You should also avoid fertilizing the maple immediately after planting. This is because trees from the nursery usually have a whole year’s supply of fertilizer. Do not start fertilizing until the following spring.
How to fertilize?
As I mentioned before, the best fertilizer for Japanese Maple is slow-release granules. It is important that the fertilizer has a nitrogen number of no more than 15 but at the same time no less than 10.
It is nitrogen that is responsible for the development of beautiful leaves. If it is too much, the leaves will be green and if too little, the leaves will be small and nondescript.
There should be less phosphorus and potassium in the fertilizer than nitrogen. The NPK formula 12-4-8 is close to ideal.
Read how much fertilizer the manufacturer recommends before applying. Usually, 2 to 3 ounces of fertilizer per year is sufficient for a 5-foot-tall maple.
Dig three small holes 2-3 inches deep around the trunk at an equal distance from one another. The holes should be at least 1 foot apart from the trunk of the tree, but no further than the drip line. Avoid damaging the roots as you dig the holes.
Spread the manufacturer’s recommended amount of pellets evenly between the holes. Next, cover them with soil and water with 2 gallons of water.
Organic fertilizer
A great addition to the mineral fertilizer is organic. They can be used together and the tree will respond only positively.
Compost works best as an organic fertilizer. Find a local supplier of quality compost with good reviews. This choice should be made with the utmost responsibility, as poor quality compost can have negative consequences.
Put the organic matter into the planting hole for the first time when you plant the maple trees. Just mix a few buckets of compost with the native soil in the hole.
Next, mulch the root zone with the same material. The mulch layer should be about 2 inches thick. Avoid volcano mulching and change the mulching material once a year.
Fertilizer burn
Too much fertilizer can cause far worse consequences than not enough.
If you fertilize too much or too often, the roots can be severely damaged. Salts accumulated from frequent fertilization can burn the thin roots that are responsible for water supply.
As a result, the leaves may turn brown around the edges or even wither completely.
A second negative scenario can be overgrowth. This will cause the leaves to lose their color and become greener. In addition, the tree will be severely depleted.
Also if you fertilize too often, the Japanese Maple will not go into a dormant state. Winter frosts will severely damage such a tree.
To avoid all this, do not fertilize more than once a year with a slow-release fertilizer. Also, fertilize no later than late spring or early summer.
Usually, 1-3 ounces of pellets are enough for young maples. Be sure to ask your supplier how much of their fertilizer is needed per tree.
If you over-fertilize a Japanese maple, water it with 4-5 gallons of water. Repeat this after a few days. Also, replenish the topsoil if possible, but avoid damaging the roots.