The Japanese Maple or Acer is one of my favourite trees,there are so many different varieties, with different colours from reds and purples through to greens and yellows, that you could have a complete collection of Acer bonsai.
Japanese Maple (Acer Palmatum) in autumn
© Walter
Pall | Dreamstime.com
Positioning
If you keep your Acer outside it does like full light but will benefit
from being shaded during hot summer sun.The Japanese Maple should
be kept out of direct sunshine during the hottest time of the day.
Also during the colder months it should be protected from severe
frost (as you would a normal sized Acer)
The Acer is suitable for most styles and can be propagated from seeds,cuttings, layering and air-layering. If you have one in your garden why not have a go at air-layering! you get a bonsai for free and you also get an older looking tree in a shorter space of time.
Japanese Maple (Acer Palmatum) in summer
© Walter
Pall | Dreamstime.com
Repotting
Younger specimens can be repotted every other year and older ones can be done every 2 or 3 years. Spring is the time to repot and pruning the roots by up to half can be carried out at the same time.
Pests and Diseases
Mildew, aphids or greenfly and root rot can affect your Japanese Maple.
Pruning of the roots is best done at the time of repotting. Usually early spring but can be slightly later if new shoots haven’t begun to develop.The idea for root pruning, is to cut the roots back to allow a fresh supply of soil between the pot and the root. Root pruning is also to encourage the finer, feeder roots;It is these feeder roots that more easily absorb the nutrients from the growing medium.
If a tree never gets root pruned it will become potbound and this is never a good situation for any plant. There will not be enough space in the pot for a sufficient amount of soil to keep the plant alive.
Lift the Bonsai from the pot and shake out the old soil. You can use a blunt stick to remove soil from in between the roots so that the roots don’t get damaged. As your collection grows you may wish to invest in your hobby and buy a Root Rake or Root Hook.
Cut the longer, thicker roots first using sharp Bonsai shears. Cut these roots further back than the thinner roots. Then cut the thinner roots and finally the finer roots can be trimmed.
Cutting the thicker roots further back gives more space for the finer roots which is what we want for a healthy bonsai.
The roots should be sprayed with water after root pruning is finished so that they don’t dry out too quickly while you prepare the pot ready for replanting.
'