Liquidambar is a deciduous tree with leaves that turn splendid yellow, various shades of orange, burgundy purple and many different shades of red in the autumn. It is an attractive bonsai tree whether it has green leaves, colored leaves or no leaves.
The American Liquidambar has been cultivated over the years to produce different varieties that have specific leaf colors in the autumn. Asian Liquidambar has not yet been hybridized for this, but the leaves still give a colorful show. Japanese Maples need cold weather to product the fall colors, but Liquidambar will produce reliable fall colors in warm climates too.
| Scientific/Botanical Name | Liquidambar Styraciflua & Liquidambar Orientalis |
| Description | Liquidambar trees are deciduous, and the leaves put on a spectacular show each fall: Their fall colors include shades of orange, yellow, gold, wine-purple and various red shades. Liquidambar consists of four species: Liquidambar Formosiana, Liquidambar Acalcyna, Liquidambar Styraciflua and Liquidambar Orientalis. The trees from all four species are resistant to pests and diseases. |
| Position | The tree prefers a full-sun location. It requires protection from extremely frigid conditions, especially freezing wind. |
| Watering | Regular watering is not required: Allow the soil to become somewhat dry before giving it water. |
| Feeding | Feed the tree every other week during its season of active growth. A fertilizer specific to broadleaf trees or shrubs will promote healthy growth. |
| Leaf and Branch Pruning | The larger branches of the tree are a challenge to bend, so pruning is the easiest way to shape the tree. When pruning is undertaken, it should only be carried out while the tree is actively growing. Fresh growth is easily torn or crushed, so it is necessary to use sharp scissors for cutting. Prune shoots back to a pair of leaves wherever branching is not required. It is important to prune top growth so as to strengthen the branches that are lower down. Leaf pruning is well-tolerated. |
| Re-potting & Growing Medium | The tree can be re-potted every other year in springtime, and this should be done while it is still in its dormancy. At the time of re-potting, prune the roots heavily. A good-quality bonsai soil will get the plant off to a good start, and the soil should be kept moist while the roots become established. |
| Wiring | Liquidambar tree buds break off very easily. As such, wiring should be carried out prior to budding or after the bud leafs out and hardening of the new growth gets under way. |
| Notes | It is easy for a bonsai enthusiast to increase his or her collection of liquidambar trees: New trees can be grown from the strong root suckers that attach themselves to some of the roots. Another way is to grow plants from the seeds of the fruit that grows on the tree. |
The Tree
Liquidambar has been growing on earth since before the last ice age. Today, it is considered a living fossil with only four species left and limited range. They produce leaves from shoots in a spray pattern unlike other deciduous trees.
The four species of Liquidambar include Liquidambar Formosiana and Liquidambar Acalcyna both of which are native to Southeast Asia and China and rarely available in western countries.
Liquidambar Styraciflua which is the American Sweet Gum tree native to Mexico and the eastern US, and Liquidambar Orientalis which is the Turkish Sweet Gum or Asian Sweet Gum are the two most often used for bonsai. These trees are not prone to pests or diseases.
The two types used for bonsai grow very well, and will throw suckers and back bud with no encouragement needed. One way to get a tree is to collect a rooted sucker.
The root systems are very strong, and if a sucker can be removed that is connected to some root, it will grow well as a bonsai. They can also be grown from the seeds that the tree produces in its fruit.
They easily germinate, so this is the best way to create a group or forest bonsai planting. They can also be bought from a nursery because they are very popular ornamental trees and often used for landscaping.
The tree looks broadly conical and produces tiny, yellowish green flowers in the late spring. The female flowers produce spherical, spiky fruit in clusters.
How To Begin
The small tree or seed can be started in the ground or in a tub. It should be grown to the desired trunk thickness, and in early spring, it should be trunk chopped. If the tree is planted in the ground, it should not be left too long. The roots are very strong and invasive and may continue to live after the trunk is chopped and grow causing problems to building foundations and the rest of the garden. The American Liquidambar reacts well to a trunk chop.
Soil
Liquidambars are not very particular about the type of soil or amount of drainage they have and will live for a long time in one pot. In spite of this, they need good soil for bonsais which is 60 per cent aggregate and 40 per cent organic matter. The aggregate soil can be:
- Agricultural pumice
- Decomposed granite
- Diatomite or turface
- Pellets of fired clay
- Orchid pellets
- Some brands of absorbent used for automotive spills
The tree can be fertilized with fertilizer that is intended for shrubs or broadleaf trees to boost vigorous growth. It should be fed every two weeks during the growing season. It should be watered when the soil gets slightly dry. If the drainage is good, it is not easily overwatered, but it should not be watered on a routine basis.
Potting
When the tree is removed from the ground and put into a bonsai pot with good bonsai soil, it can be left for a long time without repotting. It is generally considered that Liquidambars look better in unglazed pots even though they have bright leaves in the fall.
When it is time for repotting, it should be done before the tree comes out of dormancy. At this time, the roots can be heavily pruned without fear of damage because of their vigorous growth pattern.
Once a tree is removed from a pot for pruning and repotting, keep the roots damp. It can be repotted in basic soil mix every two years in the spring as the buds come out.
The tree should be protected from freezing winds and frost from below -10 degrees Celsius. It does best in full sun.
Shaping And Pruning
Pruning can take place throughout the growing season and should not be done during dormancy. Sharp scissors should always be used on new growth so that the new branch does not get crushed or torn.
Shoots should be pruned back to one or two pairs of leaves unless a new branch is desired at that place. Cutting should not be flush with the branch. The branch may die, and end the new growth that comes from the base of the existing leaves.
If pruned in this way, the branches will most likely die back and the wounds will not heal well. This is especially true for Asian Liquidambar.
The top growth should be carefully pruned back. If this is not done, the lower branches will become weak and die back. Liquidambar responds well to leaf pruning. The scars will heal quicker if it is pruned during the growing season.
Styling The Tree
American Liquidambar is very suitable for grove or forest styles. The Asian Liquidambar is also suitable for grove styles but looks better in informal styles. Informal upright, twin or multitrunk, and semicascade are the best informal styles for Liquidambar. It is not an simple tree to style because the branches easily weaken and die back and it has long internodes and coarse growth.
Liquidambar trees produce buds that are delicate and are easily bumped off the tree. For this reason, wiring should only be done before the buds begin or after it is in full leaf and the new growth is beginning to harden. Pruning is the best way to shape large branches as they are difficult to bend.