Amur maple
(Acer ginnala)
Country of Origin : Japan, China, Balkan Peninsula, Northern mountains bordering the black sea
Bonsai Styles : Formal upright, informal upright, slanting, group, root-over-rock
Zone : 3 – 9
Amur maple is a great alternative to trident maple because it is more frost resistant. Moreover, their growth is slow and they are naturally shorter in size, making them a great candidate for bonsai. In case you also want to know about other maples varieties that are a great option to make a bonsai, please read: 10 Best Japanese maple varieties for bonsai. Also read : 29 Types of Japanese Maple Bonsai You Must Try.
This vigorous tree, also known as fire maple or flame maple, is the first to display its vibrant fall colors every year. Similar to trident maple, it has three lobed leaves, however with less prominent side lobes.
An adult amur maple bonsai tree develops uniquely narrow, flaky and dull gray bark, as well as nebari (root flare). In addition to the white flowers, these amur maple also produces a red (reddish brown) fruit in the summer.
Amur maples come in different varieties:
- Compact Amur Maple – Also known as Compactum or Bailey compact, this is small sized, compact amur maple variety. It has dark green leaves and a round canopy.
- Durand’s dwarf – This amur maple variety is a shrub which is more dense than compact amur maple.
- Embers Amur Maple – Primarily grown for its ornamental fruit samaras, this variety has dark green foliage which changes its color to vibrant red.
- Flame Amur Maple – Small upright variety with a rounded crown.
- Redwing Amur Maple – Produces red fruits – samaras. Produces yellow to red leaves.
Normally sold as Amur maples, they may also be sold as Siberian maples.
Despite being non-native, they have become naturalized in North America.
For more info on other bonsai tree varieties, please read Types of bonsai trees.
Fall foliage colors depend on how much sunlight a tree receives and the soil conditions. Bright colors can be seen if the soil is healthy and the tree receives plenty of sunlight.
Best location keep Amur maple Bonsai
Amur maple loves exposure to sunlight. But, they can also do pretty well in partial shade. They are considered as outdoor bonsai tree species. Continue reading Outdoor bonsai tree care.
They are also more frost resistant maple variety.
Adaptable to conditions as cold as -37°F (-38°C), they thrive in colder climates. However, ensure that the temperature remains within the range of 50°F to 85°F (10°C to 29°C) to promote healthy growth.
However, protect the plant from late frost and also protect the roots from cold winter. For more information on how to keep your outdoor bonsai thriving in different seasons of the year, please read seasonal care for bonsai trees.
Amur maple is resistant to strong winds.
They can live between 20 and 30 years in healthy soil and environment.
Continue reading do bonsai trees need sunlight for more indoor and outdoor bonsai location ideas.
Propagation of Amur maple bonsai
Seeds should be sown in late fall (protected from frost). However this method is not very common. Also, remember that sowing seeds will not guarantee a copy of the parent plant.
It can also be propagated by using cuttings. Softwood cuttings is preferable when the new growth is still flexible and not fully matured. Take the cuttings in early or midsummer.
Using cuttings is also advantageous as it will produce the same copy of the parent plant. However, to maintain a high success rate, monitor the moisture and environmental factors.
Air layering can be done in the spring or fall season.
Please read Propagation of Amur Maple for Bonsai for more details.
Watering Amur maple Bonsai
The frequency of watering your Amur Maple Bonsai depends on various factors such as the climate, temperature, humidity, and the size of the bonsai pot. Glazed pots retain moisture better than unglazed pots. Continue reading Bonsai pot drainage.
As a general rule of thumb, it is important to check the moisture level of the soil before watering. You can do this by inserting a finger about an inch into the soil. If it feels dry, it’s time to water your bonsai.
Although Amur maple is somewhat drought resistant, during summer, water your bonsai twice a day, especially if your container is shallow.
Consider the climate of your region and the humidity levels. Dry and arid climates may necessitate more frequent watering, while humid climates may require less watering.
In winters and cold climates, decrease the frequency of watering. Make sure the soil is moist but not soggy.
When watering your Amur Maple Bonsai, it is recommended to use the “soak and dry” technique. This means thoroughly watering the soil until water drains out from the bottom of the pot. Allow the excess water to drain completely before returning the bonsai to its display area. Let the soil dry a little before watering again.
Keeping an Amur maple too dry will cause it to drop leaves.
Amur maple can tolerate hard-tap water. However, whenever possible, use rainwater for watering your bonsai. Rainwater is free from chlorine and other chemicals present in tap water, making it beneficial for the overall health of your bonsai tree.
Continue reading about how to water a bonsai tree.
Wiring Amur maple Bonsai
Amur maple is brittle in nature so use only aluminum wire for training Amur bonsai.
The branches of the Amur maple can be wired in fall, in spring before the new growth, or even after defoliation.
The wire can also be wrapped in wet cloth to ensure that no scarring occurs on the tree. Remove the wires once they begin to bite into the bark. Do not leave them on for more than six months.
Maple stems are unsightly when they have wire marks on them, so you might want to cover them with raffia.
Avoiding marking can be achieved by shaping with guy wires as well as by pinching and pruning.
Please read our detailed guide on how to wire a bonsai tree. Also, refer to our detailed bonsai tools guide and how to take proper care of your bonsai tools to know about all the tools of bonsai.
Pruning Amur maple Bonsai
When to prune amur maple bonsai?
The Amur maple can be pruned throughout the growing season, starting in late spring and continuing through the summer. This can be done specially for weak branches to strengthen them.
Formation of callus on the wounds is slow hence use a suitable cut paste on the open wounds. Also, because of slow healing, try and remove one branch at a time if possible.
When partially or fully defoliated in summer (June), the new inner buds will be more exposed to sunlight, helping them to grow. Defoliation can be done to stimulate new growth, control leaf size, and enhance ramification. However only do it on a healthy tree.
After defoliation, your Amur Maple bonsai does not require any specific aftercare. However, if you have only partially defoliated the tree, such as pruning only the top part, it is recommended to place the tree in a shaded area for about a month.
This protects the exposed interior leaves from excessive sunlight. In regions with strong sun, you can provide additional shade to protect the bark from sunburn.
Main branches can be trimmed in late winter.
Refer to how to prune a bonsai tree for more info on best practices and tips and tricks.
Pinching Amur maple Bonsai
Once two or four complete leaves have formed on all new shoots, pinch out the tips. This can be done as needed throughout the year.
Repotting Amur maple Bonsai
When to repot Amur maple bonsai?
It is important to repot the Acer ginnala bonsai every three to five years in spring before they start with new growth (before the buds start to open).
Early spring time is a good time to repot.
Apply Akadama or standard soil mix (free draining). For areas with hard water, use some sphagnum moss. OR, you can use 50:50 ratio of akadama and perlite or lava.
Also, every time you repot, perform root pruning to encourage the production of stronger roots – nebari.
Remove circling and damaged roots and prune the roots up to the woody roots. These woody roots are needed for stabilizing the plant. Keep as many fibrous roots as possible.
When you repot, don’t remove more than one-third of the roots. It takes the plant quite a while to develop a strong fibrous root ball.
You can read how to repot a bonsai tree to know more about the best guidelines to follow while repotting.
Also, continue reading about how to make bonsai soil at home and how to choose a pot for your bonsai.
Feeding Amur maple Bonsai
Similar to trident maple bonsai, fertilize with a nitrogen rich fertilizer once a month in spring. Reduce the nitrogen content in the feed every month till late summer.
The leaves will be more vibrant in color if you switch to a potassium and phosphate-rich feed in the fall.
OR
During the growing season, feed a balanced general-purpose feed to the plant. Substitute this with a nitrogen-free feed during the fall and summer.
You should not feed your tree during the winter when it is dormant.
A soil acidifier should be applied twice a year in hardwater areas.
Continue reading about bonsai fertilizer and its application.
Diseases and pest of Amur maple Bonsai
They are susceptible to bacterial diseases like Crown gall (Agrobacterium tumefaciens). Exposing the tree to direct sunlight can prevent the occurance of this disease.
Occasionally attacked by aphids. Young shoots are colonized by aphids in spring and their leaves are distorted.
Iron chlorosis occurs when plants are grown in alkaline soils or poorly drained soils due to iron deficiency. Hence make sure the soil is well drained.
Dry roots and poor air circulation around foliage can cause powdery mildew.
Refer the in-depth guide for bonsai pest and diseases identification and treatment for more details.
Also, read best practices to keep your bonsai pest free.
Amur maple bonsai care
Amur maple is susceptible to scroch if it is under prolonged exposure to high temperatures and hot winds. Hence to avoid this you can move it to a shaded area. This can also happen if the plant is water stressed. If you observe brown patches in between the veins of the leaves, make sure to water the plant.
Unlike trident maple tree, amur maple’s roots are more resistant to frost. However, still protect the roots from cold temperatures if you can.
For amur maple bonsai winter care, make sure the soil – and the roots – remain just moist, and not wet.
To prevent the soil from becoming waterlogged by winter rain, place the amur maple bonsai indoor in a shed or garage.
What to look for when buying Amur maple Bonsai
If you decide to buy root-over-rock or heavy-trunk amur maples, check the trunk for scars or old stumps of old branches. Avoid the tree having either of those defects.
The composition of a group planting (amur maple bonsai forest) should be realistic and add perspective by having trunks of different thicknesses and heights.