Posted by Brent Wilson on 9/5/2016 to Planting & Growing Tips
Though delicate looking, Japanese Maples are actually very tough and long-lived trees. They are very easy to grow in the ground or pots. Container culture can extend their useful range. They are extremely easy to grow in containers, a practice taken to it's most extreme form in the art of bonsai.
When considering the magnificent beauty and monetary value your Japanese Maple will add to your property, a little good advice will go a long way to get the most out of your tree.
Here's a breakdown of what you need to know regarding planting a Japanese maple tree...
Most any garden soil will grow Japanese Maples but the soil must be well-drained. They prefer a sandy loam soil with a low to medium amount of organic matter.
As with so many other ornamental plants and trees, constantly wet or soggy soil around the roots of Japanese maples can be problematic. So make sure to plant your Japanese Maple in a well-drained site. Heavy clay or other dense soils should be amended with organic matter. More tips for amending soil below in the step-by-step planting instructions.
Test Soil Drainage Before Planting!
Testing soil drainage is easy, and well worth the time and effort to do before planting your Japanese maple. Start by digging a hole 12" wide by 12" deep in the precise location you intend to plant your Japanese Maple. Fill the hole with water and let it drain. Then, after it drains, fill it with water again, but this time clock how long it takes to drain. In well-drained soil, which is what Japanese Maples require, the water level will go down at a rate of about 1 inch an hour. A faster rate, such as in sandy soil, may signal potentially dry site conditions, and top soil, humus or peat moss can be added to help retain moisture. A slower rate of drainage is a caution that you either need to improve drainage or look for a plant species more tolerant of wet conditions
Japanese Maple grow best in a moderately acid to slightly acid soil ranging from 5.5 to 6.5 on the pH scale. Most average garden soils fall between a pH range of 6.0 to 7.0.
Testing Soil pH
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. If you're unsure about the pH of your soil, or whether or not it's suitable for growing a Japanese maple, it's a good idea to test the soil pH in the planting area.
You can quickly test soil pH with an inexpensive soil 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?
Most Japanese Maples will grow in sun or shade. However, in their natural habitat, you would usually find them growing as understory trees in the dappled sunlight of the forest, or on the edges of woodland borders. Ideally, and especially in hot southern climates, most Japanese Maples prefer to be grown in locations that provide some afternoon shade or filtered sunlight. Direct afternoon sunlight does not kill trees, but the newest leaves of some varieties may burn and/or scald in these conditions. That being said, there are many sun-tolerant Japanese Maple varieties that have demonstrated excellent tolerance of full sun exposure in our central Georgia gardens.
Planting Instructions for Japanese Maple
VERY IMPORTANT TIP: Because Japanese maple trees require a well-drained soil, we always advise testing soil drainage in the planting area. For instructions on how to do so scroll back up this page to find instructions or click here.
To begin the planting process, start by digging your planting hole at least three times as wide and as deep or not much deeper than the root ball of your Japanese maple tree. The wider the hole the better. Place native soil removed from planting hole around the perimeter of the hole, in a wheel barrow, or on a tarp.
Depending on the type, fertility and porosity of the soil in the planting area, it may be beneficial to amend the native soil. When planting a Japanese maple tree in dense clay or other heavy soils it is beneficial to thoroughly mix in some aged compost, bagged top soil, and/or a good planting mix at a 50/50 ratio with the native soil removed from the planting hole. When planting in very sandy, quick-draining soil you might want to consider mixing in some top soil, peat moss or other organic matter that will help to retain moisture. When planting in fertile, loamy, well-drained moist soil there is no need for adding a soil amendment.
To remove your Japanese maple tree from the nursery pot it was growing in, firmly grasp the tree by the base of its trunk and very gently try to lift and remove the root ball from the container. If the root ball is stuck in the container it is best to use a cutting tool to cut the container away. After having removed the plant from the container, gently loosen some feeder roots around only the surface of the root ball. Avoid tearing the root ball apart to spread the roots as doing so can cause more damage than good.
Because Japanese maple trees require a well-drained soil, and a soggy soil at any time of year can cause root rot and kill trees, we almost always suggest planting in a raised mound. This is especially true when planting on level ground and in areas that have rainy winters. The only exception might be when planting a Japanese maple tree on sloped ground, in which case we might suggest planting with the top edge of the root ball at or slightly above ground level. How high to plant will depend on the soil drainage in the planting area. To find instructions for testing soil drainage in the planting area scroll back up this page or click here.
Moist But Well-Drained Soil (Drains 1-inch per hour): If you are planting a Japanese maple tree on level ground where the soil stays wet for only 24 to 48 hours after a heavy rain or deep soaking, or drains at a rate of at least 1" per hour during the soil drainage test, set your tree in the planting hole so that the top edge of the root ball is approximately 3 to 4 inches above ground level.
Moderately Drained / Somewhat Poorly Drained Soil: If you are planting a Japanese maple tree on level ground that drains slowly and the soil stays wet for 72 hours or more after rainfall or irrigation, or drains at a rate of 1/2 inch or less per hour during the soil drainage test, set your tree in the planting hole with the top edge of the root ball 6 inches or more above ground level. If necessary, add some backfill soil mixture to the bottom of the hole to achieve proper planting height.
Poorly Drained Soil: If your soil drains so slowly that it remains constantly soggy in all but extended drought periods, or little to no water drains from the hole within 24 hours or more during the soil drainage test, we strongly advise improving soil drainage in the planting area or selecting a different tree species that is tolerant of boggy conditions.
Well-Drained Dry Soil (Quick Draining): If you are planting your Japanese maple tree on level or sloped ground soil that drains water rapidly at a rate of 2 inches or more per hour during the soil drainage test, set your tree in the planting hole so that the top edge of the root ball is at or maybe 1 inch above ground level to allow for settling. To reduce the need for supplemental water, amend quick draining soils with top soil, peat moss or other organic matter that will help to retain moisture. Thoroughly mix soil amendment at a 50/50 ratio with the native soil removed from the planting hole.
After setting your Japanese maple tree in the planting hole, use one hand to hold the tree straight and your other hand to begin back-filling your soil mixture around the root ball, tamping as you go to remove air pockets. When you have filled the hole to the halfway point you can soak the soil. Then continue back-filling to the top edge of the root ball. If you are planting with the root ball higher than ground level taper your soil mixture gradually from the top edge of the root ball to the ground level, as shown in the planting diagram above. To avoid suffocating your tree, avoid placing any soil on top of the root ball. You can place mulch on top of the root ball later.
Step 6 (Optional)
When planting a Japanese maple tree in a well-drained or quick draining site that is far from a water source, you can use the remaining backfill soil or additional native soil to build a water retaining berm (catch basin) around the outside perimeter of the planting hole, as shown in the planting diagram above. This basin will help to collect water from rainfall and irrigation, which often reduces the need for hand watering. The berm can be removed after year or two.
Next, deeply water the planting area, including the root ball, to a depth equal to the height of the root ball. To stimulate early root formation and stronger root development you can also water you newly planted Japanese maple tree with a solution of Root Stimulator, which reduces transplant shock and promotes greener, more vigorous plants.
Apply a 1 to 2" layer of aged, shredded or chipped wood mulch or 4" layer of pine straw around the planting area to conserve moisture and suppress weed growth. As the mulch decomposes it will add vital nutrients to the soil that your tree will appreciate. Avoid installing mulch at a depth more than 2 inches. Avoid the use freshly chipped or shredded 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
Stake your newly planted tree if necessary. Shorter trees usually do not require staking.
Staking a Newly Planted Japanese Maple
Single Stake Method
For smaller trees, use one long stake driven firmly into the ground so that it crosses the trunk of the tree at an angle a foot or two above the ground (depending on height of tree). Use a piece of cloth or a section of rubber water hose to tie trunk loosely against the stake. Loop the cloth around the trunk of the tree and then cross the ends over one another before looping and tying it around the stake. Doing so help to keep the tree trunk from rubbing against the stake in windy weather. Avoid using metal wire as a tie as it can cut into the bark of your tree.
Triple Stake Method
For taller trees, you can drive three 18" long stakes at a 45 degree angle into the ground beyond the outside perimeter of the planting hole. Space the stakes evenly around the planting hole. Use wire or nylon string to tie from the stake to the tree. To protect the bark of your tree, make sure to run the string or wire through rubber hosing where it will come into contact with the trunk or branches. More on this just below.
To ensure your string or wires do not slide down the trunk of your tree, when tying your string or wire to the tree, you will need to tie above a branch. Otherwise your wires will slide down the trunk. To prevent damage to the bark of your tree, rubber hosepipe should be used where the wire touches the stem or branches.
Plant Long & Prosper!
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