Stewartia, sometimes spelled Stewartia- synonym for Dobeya, are part of the genus that includes eight to twenty species of flowering plants from the Theaceae group.
Stewartia malacodendron, and Stweartia ovalta are natives to Southeastern North America. They can be found from Virginia and Kentucky to Florida and Louisiana.
Stewratia pseudocamellia (Japanese Stewartia), have been planted in the United States.
Stewartia can be described as a shrub or tree that flowers, but is mostly deciduous. This refers to trees and shrubs which shed their leaves in the spring.
It can grow to a height of up to 3-20m in Asian varieties, and 3-5m in American species.
Because they can be grown in multiple seasons, they make a great addition to your front yard.
|Scientific Name||Stewartia pseudocamellia, S. malacodendron, S. ovata|
|Common Names||Japanese Stewartia and Korean Stewartia are also available. Deciduous Stewartia|
|Hardiness||It thrives in the U.S. Department. Zone 5-8|
|Indoor or Outdoor Plant?||Outdoor plant|
|Sun Exposure||Part shade or full sun|
|Water||Water weekly, or more.|
|Size||20-40 feet in height and between 30-50 feet in width Small tree.|
|Soil Type||Loamy, acidic, well-drained and loamy with high organic matter|
|Soil pH||There are a range of 4.5 to 6.|
|Flower||White flowers with five petals, blooms from mid-to late summer.|
The Japanese Stweartia tree (S. pseudocamellia) is native to Japan, Korea, and China.
“Stewartia” is part of the Genus that Carl Linnaeus named in 1753 in honor of John Stuart, 3rd Earl Of Bute. He was an 18th-century Scottish nobleman who became a passionate botanist and imported Stewartia Malacodendron (Virginia stewartia), into his London garden.
Stewart survived despite numerous attempts to correct the spelling of Stuart’s name over the centuries.
One species, Stewartia. pteropetolata, is evergreen. However, some botanists classify them under Hartia while others put them in Stewartia.
Appearance and Characteristics
This tree is beautiful and has large white flowers that measure 2-2 1/2 inches in diameter with orange centers. The flower usually has five petals, but it can sometimes have six to eight.
They look like a Camellia.
Although each flower has a short life span, many flowers can be kept open for many weeks.
Stewartia flowers in July through mid- to late summer.
It has unique peeling bark and green leaves.
The bark is smooth and exfoliates with age.
It is camouflaged in a molted appearance, ranging from yellow to orange with mixed grey patterns.
The seed pods have a cylindrical shape and a woody oval shape.
Each cylinder contains five chambers and five seeds.
Gardeners can take the seeds out of the dry seed capsules before they burst in fall.
It is a stunning display of color when the leaves turn from deep green to yellow or red in the autumn.
This ornamental tree is a favorite of landscapers because it blooms from mid-to late summer to the first days of fall, which is unusual for most flowering trees.
These large white flowers are up to three to eleven cm in diameter and have five petals.
Sometimes they might present with 6-8 petals.
Their bark is distinctive in that it is smooth in color and peels in fine flakes.
Autumn is a time when the leaves turn an amazing orange.
The Japanese Stewartia is an invasive species that does not drop its leaves or fruit.
The seed pod is a cylindrical, oval-shaped cone that contains a capsule made of wood.
This unique shape can be used in dry floral arrangements to add beauty and interest.
These trees love acidic soil. They don’t like dry soil or calcium-rich soil. They are tolerant of drought and they need rain.
These trees are slow to grow until established. They can reach 20-25 feet in height and have multi-trunked branches with some horizontal branches.
It is best to plant your tree in partial or full sun. They do not like strong afternoon sunlight.
This genus performs better in moderately cool climates.
Stewartia trees can reach 24 inches in a year.
Water frequently to keep soil moist and wet.
There are mixed data on drought tolerance, so be aware of signs of heat damage.
Local growers recommend keeping them moist, but not soggy.
Stewartia trees are not always compatible with other shrubs and trees.
The truth is, they can be difficult to establish. However, once established, they are quite easy to maintain as long as they have enough water and well-drained soil.
It is possible to start with nursery stock that has been well grown. Place it in an area that gets little sun during the day and water it carefully for the first few years.
Pruning and propagation
Stewartias can be kept neat and tidy by themselves and don’t require much pruning.
If the landscaper or gardener so wishes, they are happy to help with pruning and shaping.
If trees are placed closer together, smaller varieties can be sheared to form a formal hedge.
Top Tip Cut cross- or misdirected branches early in the growth cycle and then remove lower limbs when the tree reaches height.
Stewartia henryae, an open-pollinated hybrid of Stewartia pseudocamellia and Stewartia monoadelpha is called Stewartia henryae.
This unique combination of the two parent species creates a plant that is truly unique.
Many display white flowers, like the S. monadelpha, and bark like S. pseudocamellia.
Many people stratify seeds when you start from seed.
Stratification is a horticulture process which stimulates the natural conditions seeds must experience before they can germinate.
This is embryonic dormancy, and most seeds won’t sprout until this phase ends.
A stratification process is required for Stewartia seeds.
For 120 days, the seeds should be kept at 15-20°C (59-68°F) and then cold stratified for 90 days.
Most people keep their seeds in the refrigerator for at least 90 days.
For the best chance of germination, some gardeners prefer to stratify in warm and cold periods.
It all depends on where you live and how cold it is.
Stratification Warm stratify up to 120 days
For 90 days, cold can satisfy
Scarification is the process of soaking seeds in water at room temp for 24 hours prior to planting.
Seeds should be sown 1/8″ deep. Press down on the soil and level it. Mulch will help keep the seedbed moist.
Potting and repotting
A small tree can be transplanted from a nursery to an area in the spring, or from one container to another as needed. However, they don’t like being transplanted.
When planted in ground, the tree will grow best in moist soil that is moderately acidic and with good drainage.
It is not suited for heavy clays, dry or rocky soils or soils that don’t drain well.
Notice: It may have trouble absorbing nutrients from neutral or alkaline soils.
It is not able to establish itself easily with other garden trees or shrubs.
Plant trees once a year, in the spring with balanced granular fertilizer at 10-10-10.
Stewartia can be paired with Hakonechloa macra (also known as Japanese forest grass), Sunburst Hypericum and Japanese Spurge.
They can be paired with other low-maintenance shrubs such as shrub roses, spirea and ninebark.
Pest and disease problems
As with most trees, problems can arise from damage to or injury to the bark.
The tree is not susceptible to diseases or pests, but it is quite hardy.
It is important to take precautions in order to preserve the tree’s health.
To avoid the tree falling over during winter storms, plant it in spring.
Some support can be beneficial for young trees during their growth years. This will help stabilize them until they have a strong root system and their trunk is strong enough to withstand the weather and wind.
Sunburn is a term that refers to sunburn caused by too much afternoon sunlight.
The tree can be damaged by heat stress.
This will make it more vulnerable to disease and pests.
This can be avoided by placing your tree in partially shaded areas or an area that doesn’t get direct sunlight for long periods of time during the day.
It is almost like our skin being cut when the bark becomes damaged.
This can lead to open exposure that invites germs and pests.
Stewartia’s bark is fragile and can be easily damaged.
When pruning or mowing around trees, it is important not to cut the bark.
You might place decorative rocks and gravel around the trunk once it is established. Or, put a low fence around it so it doesn’t get harmed by weed whacking or mowing too close to it.
It could be a sign that your tree is being overwatered if the leaves turn brown.
Stewartia trees need moisture, but not too much as they can get root rot.
You can find high quality seeds:
If you are in the US, Stewartia pseudocamellia (Japanese Stweartia 3-year old trees from Japanese Maples and Evergreens can be ordered on Amazon.com
Should I start from seeds?
It is much better to start with strong nursery stock trees than seeds.What is it that makes this tree so special?
This tree can be used in all seasons, but it is especially stunning in fall.
The unique, thin, multicolored bark is distinctive. It can be orange, yellow, or grey.
When does Stewartia bloom?
Flowers bloom in the middle to late summer, when other trees don’t have flowers.