Stewartia / Stuartia
(Stewartia)
Country of Origin : Japan
Bonsai Styles : Formal upright, group
Zone : 6 – 8
Stewartia is a deciduous tree (closely related to camellias). It has become increasingly popular among bonsai growers in recent years.
It is one of the few bonsai specimens that looks stunning in winter and early spring more than any other season.
Their leaves have a pointed, oval shape. Their cup-shaped flowers are white or creamy white.
It has a beautiful shiny copper bark and neat, delicate twig pattern, making an excellent Stewartia bonsai.
Additionally, the fall foliage turns spectacular scarlet and purple as the season progresses.
The Stewartia tree has a strong vertical growth habit. As a result, making broad, spreading bonsai styles impractical.
The two main varieties of Stewartia used to make bonsai are – Stewartia monadelpho and Stewartia psuedocamellia (Hime Shar, Japanese stewarti).
Stewartia psuedocamellia originates from Japan.
Stewartia monadelpho originates from south Japan and Korea. It is a dwarf variety which is sometimes also known as ‘deciduous camellia‘.
Despite the flowers, stewartia bonsai trees are prized for their winter appearance. During aging, the bark becomes almost purple and flakes off in large patches, revealing an orange layer underneath.
The smooth orange bark in its fresh state appears to be polished.
The combination of color of bark, buds and twigs, and branches creates an impression of a flickering flame against the backdrop of pale blue or dark winter skies.
Best location to keep Stewartia Bonsai
Stewartia bonsai trees can tolerate hot weather, but they prefer partial shade, especially in extremely hot conditions.
Especially, make sure to keep the bonsai in partial shade when the tree is flowering. This will prevent the flowers from being scorched.
You can place the bonsai under the direct morning sun. However, keep the bonsai in the shade of a tree or a structure during the afternoon. So, that there is still some overhead light for the bonsai.
Stewartia bonsai can tolerate several degrees of frost for a short time in winter and early spring. However, in cold conditions, move the bonsai container in a frost-free shed.
Make sure that the tree is not exposed to temperatures lower than -5°C (23°F).
Leaf margins can also be scorched by drying winds.
You can also spray the foliage in hot weather.
The shade provided by a house is more beneficial than an overhead tree since it permits uninterrupted overhead light.
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 Stewartia
Stewartia tree can be propagated by using softwood cuttings in summer.
They can also be propagated by sowing seeds in spring and winter.
Watering Stewartia Bonsai
Water regularly throughout the growing season. Bonsai soil should not be allowed to dry out.
Stewartia, like other thin-leaved ericaceous plants, dislikes being dried out and the leaves shrivel up quickly when water is not available.
Stewartia do not like hard water. Use soft water (lime-free). Using rain water whenever possible is best.
Reduce the frequency of watering in winter. Keep the soil moist but not waterlogged.
It is not a good idea to stand the bonsai pot in a water tray, as this will cause the soil to waterlog.
Read watering bonsai tree for more details about immersion technique.
Wiring Stewartia Bonsai
Branches can be shaped by pruning alone, so little wiring is necessary.
Stewartia Bonsai tree can be wired in midsummer.
Wires should not be left on the tree for more than one year.
Wire carefully; the bark is easily damaged.
Pruning Stewartia Bonsai
When to prune Stewartia bonsai?
How to prune Stewartia bonsai?
It is appropriate to prune the stewartia bonsai right after they flower. However, be sure not to prune the shoots that grow in the growing season since they will produce next year’s flowers.
Maintain the overall shape of the tree by lightly pruning or pinching out the tips of the growing shoots at the end of summer.
You may want to remove some of the inner branches if they become too crowded in order to allow air and light to penetrate and create a better structure.
Cut just above the outward-facing buds.
In case you are planning to repot, prune the branches in early spring, almost 3 weeks before repotting.
In order to prevent unsightly swelling as the pruning wounds heal, hollow out the wounds and seal them.
Pinching Stewartia Bonsai
Keep pinching throughout the growing season.
As soon as two complete leaves have formed, pinch out the growing tips of all shoots. Don’t pinch extension growth is required for overall shape development.
In addition, if any unwanted adventitious or inward-growing shoots appear, remove them immediately.
Repotting Stewartia Bonsai
When to repot Stewartia bonsai?
Stewartia bonsai tree can be repotted every 2-3 years in early spring.
Hard prune the thick roots while repotting. However, lightly prune the finer roots.
A Stewartia hates lime. They must be planted in acidic soil. Use an ericaceous compost for the organic content if you want to be safe.
You can use a free-draining, lime free bonsai soil mix. It is good if the soil mix contains sphagnum peat or ericaceous compost.
OR
You can also use a soil mix consisting of 20% grit and 80% organic matter.
OR
You can also make a soil mix loam, sharp sand and sphagnum peat (or ericaceous compost) in the ration of 1:1:1.
Must Read: Bonsai Soil Recipes
Must read : Choosing the right bonsai container
Feeding Stewartia Bonsai
Apply fertilizer once every two weeks in the growing season.
Apply a nitrogen-rich fertilizer immediately after flowering.
Apply a nitrogen free feed in fall.
You should only use fertilizers that are recommended for heathers, camellias, and other lime-sensitive plants.
Read more about bonsai fertilizer and its application.
Diseases and pest of Stewartia Bonsai
Stewartia trees can suffer occasional problems of caterpillars and aphids. You can remove caterpillars by hands.
Use a systemic insecticide if aphids can not be removed manually.
This species is susceptible to vine weevils. Look for their larvae when repotting. After removing and killing any larvae found, water nematodes into your compost in late spring.
Stewartia bonsai care
The scars of pruning on stewartia heal rapidly, and if hollowed and sealed properly, they will disappear and become completely smooth. However, if done incorrectly, it will produce an unsightly lump which will ruin the look of the bark.
Stewartias are difficult to maintain. It will take you some time (may be a year or more) to balance all the factors like, feeding, watering and soil. However, once you hit that sweet spot, all the hardwork will pay you back with a beautiful Stewartia bonsai.
The leaves of a Stewartia bonsai that is exposed to wind and hot sun will also scorch or fall, so place it in a sheltered location where it will not receive direct sunlight after midday.
What to look for when buying Stewartia Bonsai
Before making a purchase, check the bark for any signs of any pruning wound which was not sealed properly.
Look for a bonsai specimen which has got a good root formation at the soil surface.
In case you are purchasing the bonsai tree at the time when the leaves are not dropped from the tree, make sure you inspect the trunk and branches. This will help you in confirming 2 things – (i) making sure that there are no ugly marks or swelling on the tree. (ii) You will be able to kind of picture how the tree will look when the leaves are dropped in winter.
