Japanese Maple (Acer Palmatum)

The main varieties are:

• Aoyagi
• Deshojo Shaina
• Katsura
• Arakawa: Characteristic for its bark, they are somewhat delicate, branches dry easily, especially at the apex.
• Deshojo: Characteristic for its red leaves throughout the year.
• Yamamomiji: Very easy to grow.
• Green Carpet

Japanese Maple (Acer Palmatum) Bonsai Care Guide

How should I water?

This is a delicate tree regarding water quality; it is important to water with soft water, either rainwater or distilled water. If the tap water is soft, there will be no problem, as is the case in Madrid. If the tree’s leaf tips dry out, we are probably not using soft enough water. Hard water clogs the fine roots, causing the tree to struggle to obtain the necessary nutrients.

If you do not have soft water, an option may be to grow the boxelder maple, a variety of maple much more resistant to calcareous water.

It does not tolerate drought well; regular and abundant watering is recommended. Although we recommend reducing watering when the tree is leafless during the winter to about 1 watering per week, moving to daily watering when it has leaves and the temperature accelerates the substrate’s dehydration.

Should I leave it in full sun?

It does not tolerate being in full sun for many hours; it is best to find a place where it only gets 1 or 2 hours of sun that are not peak hours like noon. If such a place is not available, you can use a shade cloth that filters 50% of the light rays.

Should I worry about sheltering it during the winter?

If there is one thing to worry about with a Japanese Maple, it is the heat; this is where this species suffers the most. As for low temperatures, it can withstand below zero without problems, even with snow. Although it is true that late spring frosts can burn the leaves.

How often should I fertilize?

Fertilize in spring and autumn with slow-release solid organic fertilizers so that its delicate roots can absorb what they need without getting clogged. Refrain from liquid fertilizers.

When and how should it be pruned?

Always in autumn after the leaves have fallen.

If we want to avoid very large scars that are difficult to heal, our recommendation is to leave a centimeter of the trunk when cutting. After a year, with the concave cutter, we will cut that 1 cm trunk and fix the wound. This way, we will get the wound to close much faster and not be so bulky.

It is also worth noting that since it is a species with thin bark, it is not advisable to clean out the wounds as a hole may be left in it later.

In the case that we have a large scar that has stopped closing, we can revive it by making a wound on the callus lip with a cutter on the inside of it.

Use healing paste with fungicide to avoid fungal problems in large wounds. For example, Top Jin.

Can I get new branches?

The Acer Palmatum easily creates new branches from the same woody trunk or from each node.

To maintain a compact design, it is important to control the distance between nodes in pruning; this way, we will force the tree to produce branches with shorter nodes.

Can I pinch?

As it is a fast-growing tree, it is recommended to pinch the new shoots several times in summer.

When is the best time to wire?

It can easily get wire marks if left on during the spring as this is when it grows fastest, so it is better to wire in October and leave it until March.

How do I know when I have to repot?

The roots grow very fast, which will force us to repot every year in young specimens and up to 3, 4, or 5 years in older specimens. It admits drastic root pruning, although if it is done, we must keep the tree in the shade for a few days so that it does not dehydrate excessively.

To get a good nebari, we must cut the roots that go straight down, especially those that come from the very foot of the trunk. We must also cut those that cross others, those that go upwards, or those that grow above where we have decided the tree’s nebari begins. We must also transplant annually if we want to widen the nebari.

If we do not have a good root system, we can always resort to air layering at the base of the trunk where we will force new roots to grow. To do this, you have to remove the bark from the foot and cover the entire base with substrate or sphagnum moss until we detect that roots have come out.

What substrate or soil should I use?

It is important to use very draining and acidic substrates (pH from 4 to 6). Some mixtures that we have tried successfully are:

• 70% akadama and 30% kiryuzuna
• 50% akadama, 25% kiryuzuna, 25% pumice and a little (a shovel) of kanuma
• 50% akadama, 25% kiryuzuna, 20% kanuma and 5% carbon

How can I propagate it?

It is very easy to reproduce it by seeds that can be collected in the spring. Air layering and cuttings are also a good option as they root easily. The best time to take cuttings is in winter.

What pests and diseases can affect it?

If we detect that the leaves are bulging and bent inwards, we may have verticillium fungus. Green aphid is also a potential danger when it has tender shoots.

What styles or shapes can be made?

Acer Palmatum are very popular in Kabudachi or multiple trunk style, but any style can be achieved.

What should I take into account when buying a specimen?

It is important to check if the leaf tips are dry as this may indicate watering with water that is too hard or of poor quality, which could have caused its fine roots to be clogged.