The Trident maple (Acer buergerianum) is a hardy, vigorous tree that responds well to bonsai culture and is a great plant for beginners. This tree was bred in Taiwan and eastern China, where it has been a popular bonsai plant and is also known as the Chinese Maple bonsai tree.
Trident maple bonsai trees have has shown their value over the years and were first introduced in Europe and North America in 1896.
Not only are these trees hardy of abuse, but their shallow root systems make them great for planting in cities. Trident maples are often grown along sidewalks in cities and in city parks, but they also have great characteristics for bonsai. Trident maple bonsai trees are vigorous and can quickly build wide nebari and a fat trunk. The trees tolerate heavy pruning of their leaves and roots.
The smooth grey bark flakes off on older trees, resulting in patches that are cinnamon coloured. The leaves start out with an orange tinge before turning green over the summer and then fiery in the autumn with colours ranging from red to orange to yellow.
Care Guidelines For Trident Maple Bonsai
Ideal Placement
Trident maple bonsai trees should be grown outdoors during most of the year. Place the tree in a sunny airy place but protect it from strong afternoon sunlight during hot weeks in the summer and from strong winds.
Be careful about temperatures during the winter. The tree should not be exposed to temperatures lower than -5ºC (23ºF). An ideal place to overwinter a Trident maple bonsai is a cold room or a frost-free greenhouse.
Water Requirements
Since these bonsai trees grow vigorously, they need a lot of water during the growing season. Keep the soil evenly moist, but make sure it is well drained. However, don’t overwater them. Avoid water with a lot of calcium, and use rainwater if you can obtain it. Reduce the amount of watering over the winter, but keep the plants damp.
Soil And Fertilising
Fertilize your bonsai tree monthly with solid organic fertilizer once a month or liquid fertilizer once a week.
Pruning Times
Allow the new shoots in the spring to grow until they have several pairs of leaves. Then shorten the stems and leaves to just one pair. The top of the plant tends to grow more strongly than the lower branches. Therefore, you should prune the top more to let the weaker branches catch up. You will need to continuously shorten the new shoots that appear during the whole growing season.
With mature bonsai trees, you will need to pinch the young shoots very early, so the finer twigs on the outer canopy will not thicken. If you need to prune trunks or large branches, do so in the summer, so the wounds will begin to heal immediately. You should always seal the wounds with cut paste to avoid infection from fungi and prevent the bark from dying back.
You should defoliate your bonsai tree – remove some or all the leaves in the summer. If you live in a region with long warm growth periods, you should do this several times a year, so the leaves will be smaller. This will also provide light for the inner twigs, so they will not die. If the trees have not been defoliated, remove the largest leaves at any time.
When the leaves fall in the autumn, you can take this opportunity to shorten the twigs and remove the ones growing in odd directions, such as downward or upward.
Keep all but two buds from growing from the same point. You may need to use a magnifying glass to figure out what direction the buds are pointing in. This will help you decide where to cut, so the shoots will grow where you desire the following year.
Propagation Management
You can grow Trident maples from cuttings, seeds, or air-layers.
Potential Pests And Diseases
Vigorous specimens are rarely attacked by diseases and pests. Scale insects, aphids, spider mites, or caterpillars sometimes attack Trident maples. Use an appropriate pesticide, such as neem oil, to control them.
Sealing the wounds immediately will prevent the wilt-causing fungus Verticillium from taking hold in your tree. The plants are susceptible to root rot if they are overwatered. The leaves can turn yellow if the plants are frequently watered with water than contains a lot of calcium. If the plant does not have adequate air circulation, powdery mildew can be a problem. A spray of half milk and half water will often control this disease.
Repotting Times
Since the Trident maple bonsai tree roots grow quickly, you should repot your plants every year or every other year during the early spring before the buds unfold. Larger older plants can be repotted less frequently. Since the roots grow strongly, you can prune them heavily. Unlike many other plants, Trident maples will tolerate having their roots bare while you repot them. Plant in a soil mix that drains well and has a pH between 5 and 7. Some experts recommend using Japanese akadama clay as the soil for Trident maple bonsai trees.
Wiring Your Bonsai
The winter dormant period is a good time to wire the young branches and twigs. However, check and remove the wires, so they will not scar the bark after the spring shoots have emerged. You can position stiff older branches with guy wires.