The Japanese Maple (Acer palmatum) is one of the most well-known and widely used maple trees in gardens around the globe, and is an ideal specimen for bonsai. The Japanese maple bonsai tree is appreciated for its compact size, delicate foliage and brilliant fall colors – from bronze-gold to deep crimson-red. This maple is native to Japan and China.
The leaves of the Japanese Maple, with it’s five lobes, resembles a human hand, and this is where it’s botanical name comes from. It is among the most popular species used for bonsai. Varieties of the Acer palmatum include both red and green varieties, thread leaf and lace leaf varieties. The most popular of these varieties is the red variety.
Regular watering is critically important to your Japanese maple bonsai and should begin in the springtime when the first signs of new growth appear, and continued through summer into late fall when the tree has lost all of it’s leaves. Proper watering is so important to the health of your bonsai trees. Japanese Maples prefer moist soil. Be sure you check on the moisture level of your tree’s soil on a regular basis and water as needed. The best way to water your Japanese Maple is to water it in the morning. Let it dry out over the course of the day but never allow it to become completely dry. It’s important that your plant’s pot has sufficient drainage holes to allow all the excess water to drain out. The water must drain thoroughly or the plant’s roots will sit in water and may develop root rot.
Your tree will benefit greatly from getting the proper amount of sunlight – not too much and not too little. But Japanese maples have somewhat "delicate" and sensitive foliage, and need some protection from intense mid-day summer sun, and also from leaf-drying winds. The ideal location for your Japanese maple bonsai is in a place where it will be able to receive direct early morning and evening sun, but that is protected from being in direct sunlight during the middle of the day when the sun’s rays are the most intense, and is the hottest part of the day.
Maple tree leaves can burn when they are exposed to the mid-day sun. In the spring when your tree is beginning to put out its leaves, and the mid-day sun is less intense, you should give your plant full sun all day long. "Wind burn" can result from unprotected exposure to hot, dry summer winds that will strip you plant’s leaves of important moisture, so take care to protect your tree from these winds too. Be particularly careful of keeping your bonsai out of direct sun and winds if you have just recently pruned the plant’s roots as the roots will have difficulty providing the leaves with sufficient water which will also lead to leaf burn.
Keep your Japanese Maple sheltered from winter winds too, because these winds can also be quite dry, and if your bonsai is left exposed to these winds it could result in serious damage to the tree.
All plants love a humid environment, and your Japanese Maple will thrive in this type of environment. You can increase the humidity levels for your bonsai by filling a shallow container with small stones, and then covering the stones with water, and then placing your bonsai pot on top of the stones. Make sure your bonsai pot is not actually sitting in the water. As the water evaporates from the shallow pan it will furnish humidity to your bonsai plant which will slow the process of transpiration. A fine mist sprayed on your bonsai frequently will also increase the humidity level and reduce the rate of transpiration of water from the tree’s leaves.
You can start fertilizing your Japanese bonsai in the spring after it has begun showing new growth. Use a high nitrogen, slow release fertilizer, and continue fertilizing every two to three weeks clear through mid-fall. The best natural fertilizer that is high in nitrogen is fish emulsion. If you’re using a chemical fertilizer make sure that you only use a half strength solution. A balanced 20-20-20 fertilizer is recommended. You should stop fertilizing your bonsai tree during the hottest weeks of the summer to avoid any possible damage. You can help prepare your bonsai for the upcoming winter by switching to a low nitrogen fertilizer beginning in mid-autumn. This will harden off the current years new growth.