Queensland Bottle tree / Narrow leaf bottle tree
( Sterculia rupestris / Brachychiton rupestris )
Country of Origin : Australia
Bonsai Styles : Informal upright, group
Zone : 9 – 11
The following care instructions can be applied to both narrow leaf and broad leaf bottle tree bonsai. Brachychiton populneus has broad leaves.
Queensland Bottle Tree (also known by many names such as: Narrow Leaved Bottle Tree, Queensland Barrel Tree, Australian Barrel Tree, Dandygook, Kurrajong or simply bottle tree) makes for a great bonsai tree. They are also a good indoor bonsai tree.
It is a deciduous, subtropical or tropical succulent tree.
Its distinct looking (swollen) trunk and the easy to grow nature makes this tree an attractive bonsai subject to bonsai enthusiasts all around the world.
With shallow veins and deeper fissures, it has dark gray bark. However, in young trees, the color of the trunk is grey or green which is also the same color of the small branches.
The branches have an upright growth habit. And the tree does not flower.
There are many varieties of bottle brush trees, and all the leaves on the stem are alternately arranged. However the shape of the leaves can vary from deeply divided to narrow and elliptical.
As the name suggests (narrow-leaved bottle tree), the leaves of the tree are glossy dark green on the top side, paler on the underside, narrow in width and end with a point.
The leaf blades also have a raised mid-rib on both upper and lower surface.
Read more about other bonsai trees species in : Bonsai tree care
Bottle tree are ‘vascular’ trees that have the ability to draw water from the ground and store it in its trunk. (for the time of drought).
Because of this, the tree has a swollen trunk.
Bottle tree (Brachychiton) should not be confused with boab tree (Adansonia). Even though, these trees somewhat have the same look, they belong to completely different tree families.
Bottle trees also grow taller than a boab tree.
Best location to keep Queensland Bottle tree Bonsai
One of the main reasons it works so well as an indoor bonsai is due to the fact that it is extremely resistant to poor management.
Throughout the year, you can keep the bottle tree bonsai indoors in virtually any position you choose, as long as you avoid cold drafts as much as possible.
However, in an ideal situation, keeping the bonsai pot in front of a nice bright window with a lot of light coming in is a good idea.
These trees can sustain a temperature from 23°F – 113°F (-5°C to 45°C).
The temperature is not of much significance, but I would suggest a temperature of between 41°F – 75°F (5°C – 24°C) would be ideal.
IMP: Refer sunlight requirements for indoor plants for more indoor gardening ideas. Also, refer to do bonsai trees need sunlight for more indoor and outdoor bonsai location ideas.
Propagation of Queensland Bottle tree
Narrow leaf Bottle tree can be propagated by using cuttings or by sowing seeds. However, it should be noted that using seeds is easier than using cuttings.
While using seeds, be careful as these seeds have tiny hairs on them. These hairs can cause irritation on your skin. The scarification of dried out seeds improves their germination.
Sow the seeds (in summer) in a pot with growing medium ( e.g. 1:1 ratio of peat moss and perlite ). Cover the pot with a plastic bag.
Now place the pot in a warm location (preferably with a temperature of 80°F (26°C) ). You can also use a bottom heater. Water the pot. Germination should occur within 15-3- days.
While using cuttings, take hardwood cutting ( in summer ; 6 inches long at least). Remove the bottom leaves and apply some rooting hormone to the bottom of the stem.
Plant the cutting in the rooting medium mentioned above. Cover the pot with plastic. Usually, the rooting can be seen in 2-3 months.
Watering Queensland Bottle tree Bonsai
You can water it once a week when the tree is in active growth. And then reduce the watering frequency to once every 2-3 weeks when the tree drops leaves.
For watering this bonsai tree, I recommend using bonsai immersion technique.
This species of tree has very bulbous roots and trunks, and it is capable of storing a considerable amount of water for times of drought.
The tree is one of the few bonsai trees that can be left without water whilst you go on holiday.
The only thing that will happen if it gets too dry is that it will cease to grow.
It is also resistant to frost if it is kept dry during the winter months.
Read watering bonsai tree for more details on immersion technique.
Wiring Queensland Bottle tree Bonsai
Because of the shape and structure of the trunk and the natural growth habit of the branches, wiring of the tree is not necessary. However, if you are trying something new and want to bend the branches a bit more laterally, you can perform wiring at any time of the year.
Also, the tree is very susceptible to marks. so be very careful.
Pruning Queensland Bottle tree Bonsai
When to prune Queensland Bottle tree bonsai?
How to prune Queensland Bottle tree bonsai?
This tree is an extremely vigorous grower.
In spite of the fact that trimming is not essential for the health of bottle trees, they respond well to pruning.
Pruning of bottle tree bonsai can be done at any time of the year and you can prune it back hard to your liking.
Regular pruning will make it more fuller, give it a more tree like shape and also top pruning will help you in maintaining the desired height.
You can remove 1/3 of the trees canopy. This will also help in providing more light to the inner section of the tree.
It is recommended to apply cut paste because if the pruning woulds are exposed to moisture then they will rot.
Make sure to prune with sharp tools. Sharp cuts are easier to seal.
Repotting Queensland Bottle tree Bonsai
When to repot Queensland Bottle bonsai?
Bottle tree bonsai can be repotted every 2-3 years. They are very easy to repot.
You can also perform heavy pruning of the taproot. However, make sure you do not touch the root ball.
The roots also grow fast, and to felicitate root growth, you can apply some bottom heat.
You can choose a deep container for the tree as the root system is quite extensive. But, keep in mind that the tree will also grow big as a result.
You can use a basic free-draining, acidic bonsai soil mix as a potting soil.
Must Read: Bonsai Soil Recipes
Must read : Choosing the right bonsai container
Feeding Queensland Bottle tree Bonsai
Apply a balanced feed to the tree when it is actively growing (or a fertilizer suitable for tomatoes).
For young trees you can apply a feed which is high in phosphorus. This will encourage root growth.
Avoid fertilizers with high nitrogen content.
You can stop the application of feed if the tree is kept cold in winter. However, if kept in warm temperature you can apply a balanced fertilizer at half strength.
Read more about bonsai fertilizer and its application.
Diseases and pest of Queensland Bottle tree Bonsai
Generally these trees are pest free. However, Spider Mites and giant white flies can attack the tree in rare cases.
The giant white flies look like moths. These insect love sucking on the sap of bottle tree. Although not fatal to the tree, these insects can leave honeydew on the tree which can lead to sooty mold.
Remove them manually or by using a jet of water. Remove the infected leaves.
Prune the foliage infected with spider mites. Or you can also remove them by water jet.
Further control is possible through the use of horticultural oils and insecticidal soaps or miticides.
Texas root rot, can cause the leaves to wilt and turn yellow. It will also rot the roots. This is a fatal disease. This disease can not be treated. Hence, make sure that is ample amount of drainage in the bonsai soil.
Queensland Bottle tree bonsai care
When subject to drought, the tree will shed some of its leaves. Water the tree when you see this with your bottle tree bonsai.
The size of the root ball greatly effects the size of the tree. Root pruning is a major factor by which you can control the height of the tree. Hence choose the size of the pot according to the size of the bonsai in your mind.
