The Japanese stewartia is an ideal match for anyone who loves the beauty of rich fall foliage but doesn't have a lot of land to work with. Native to Japan, this small specimen tree is known for its attractive exfoliating bark and delicate blooms in the late summer and fall that closely resemble camellias, as evidenced by its species name, Stewartia pseudocamellia.
Planted in spring or early summer, this slow-growing, low-maintenance deciduous tree will eventually grow cup-shaped white flowers with showy orange-yellow anthers that develop in the early summer. Its foliage of dark-green leaves transforms into gorgeous autumnal hues of red, orange, and burgundy as summer turns to fall. As its leaves shed, a flaky, multi-colored, and pretty patchwork bark is exposed that gives the tree some winter interest. The bark peels away in strips of gray, reddish-brown, and orange.
|Common Name||Japanese stewartia, common stewartia|
|Botanical Name||Stewartia pseudocamellia|
|Mature Size||12-40 ft. tall, 8-25 ft. wide|
|Sun Exposure||Full, partial|
|Soil Type||Moist but well-drained|
|Soil pH||Neutral, acidic|
|Bloom Time||Summer, fall|
|Hardiness Zones||5-8 (USDA)|
Japanese Stewartia Care
The Japanese stewartia doesn't always establish itself as easily as other shrubs and trees, so it takes tender loving care or it may fall over. It is commonly sold as either a large multi-stem shrub or as a tree, but it is not a suitable to be grown as a container plant.
When choosing a location for your Japanese stewartia, be sure to provide a site that's sheltered from cold, dry winds, which will damage buds and flowers. Do not plant in the fall or winds and storms may topple the plant, but use supports and stakes to help stabilize the tree.
Since it's a smaller tree, it's a good fit for more compact landscapes. A multi-season tree, consider planting a Japanese stewartia in your front yard or any other focal point (such as near a patio or outdoor room). It's a popular choice because it provides homeowners with a colorful and textural show for every season.
There are no known pests or diseases that particularly affect the tree.
This tree grows best in full sun to partial shade. However, the leaves are prone to sunburn in very strong afternoon sun. It should be shaded during the hottest times of the day.
The Japanese stewartia prefers moist, well-drained soils that are moderately fertile.
Water the tree regularly during the first year after planting to facilitate a deep and extensive root system. Maintain watering after its first year for wet, evenly moist soil. These trees should be watered at least weekly for optimal growth and will require deeper watering during extended dry periods. Mulch during cooler months to keep moist.
Temperature and Humidity
If you live in a region with warm summers, plant your Japanese stewartia tree in a protected location where it can receive some shade from the heat of intense afternoon sun (such as the east or north side of a house or building).
Fertilize your Japanese stewartia during its early years; do so in the spring with an acidifying organic granular fertilizer.
Varieties of Japanese Stewartia
There are several cultivars of Japanese stewartia, including:
- 'Ballet', a cultivar with a spreading habit
- 'Cascade', a semi-weeping cultivar
- 'Milk and Honey', with lots of large, milky white flowers
- 'Pilar Bella', a cultivar with a columnar growth habit
Pruning is rarely needed for these trees, but winter (or any time after flowering) is the best time to remove broken branches as well as those that are crossing or rubbing. When working on your tree, be careful not to hit the bark with equipment. The bark is extra thin and susceptible to damage. Prune the lower limbs as the tree grows; in doing so, you will reveal the fascinating spectrum of the bark's colors.
Propagating Japanese Stewartia
You can propagate the Japanese stewartia by softwood cuttings in the early summer or semi-hardwood cuttings in the mid- to late-summer. In either case, you should be aware that the failure rate is high, mostly due to maintaining the right temperature for the cuttings during the winter. Here's how:
- Using sharp garden shears, take cuttings that are between 3 to 5 inches and strip off all but the upper levels of foliage.
- Scrape off the woody layer at the bottom of your cutting and dip in rooting hormone. Liquid KIBA tends to have a good success rate with this plant.
- Place the cutting in a mix of Perlite and Perennial Mix.
- Place your potted cuttings somewhere where the temperature will stay around 41 degrees Fahrenheit throughout the winter. Place in bright, but not direct, light.
- Keep the soil moist but not soggy.
- If your tree takes successfully, it will be ready to transplant outdoors in the early spring after its roots have sprouted.
How to Grow Japanese Stewartia From Seed
Though germination is an extremely slow and complex process due to a very particular pattern of temperature variation, you can also propagate Japanese stewartia by seeds. To do so, soak the seeds for 24 hours. At this point, the seeds should have swelled. If they haven't, grind them up in your hand with sand to help penetrate the outer layers to let the water. Soak them again for about 12 hours.
Place the seeds in a potting mix and keep them at a temperature of 59 to 64 degrees Fahrenheit for 120 days, making sure to keep the pots moist and the seeds from drying out. Then, place the potted seeds in cold conditions for another 90 days where the temperatures will hover in the 45-degree-Fahrenheit range. Finally, before planting the seeds, germinate them by exposing them to temperatures around 68 degrees Fahrenheit. After the seeds germinate, they can be sown in shallow soil outdoors.
It's always best to plant Japanese stewartia in locations that offer some protection from the harshest winter weather. Once your tree is established, however, there are no necessary steps to take for overwintering.
How to Get Japanese Stewartia to Bloom
If your newly planted Japanese stewartia isn't blooming but it is otherwise growing and located in favorable conditions, it might still be too young to bloom. It could take a couple of more years until you see it flowering.
Common Problems With Japanese Stewartia
As mentioned, the Japanese stewartia tree takes a while to develop its root system, so if it is not properly braced in its early days, it could fall over.
The leaves are also subject to burning if the tree is not planted in a partially shaded area. Its thin bark is also prone to damage if hit by machinery or tools, so it's a good idea to put a small fence around the tree, as damaged bark could invite pests or diseases.
What should I plant with Japanese stewartia?
Is the Japanese stewartia drought tolerant?
No. The soil around this tree always needs to be kept moist. If not, the tree may not survive.
How long do Japanese stewartia trees live?
If well cared for, these trees can live up to an impressive old age of 150 years.
Who was Stewartia named after?
The genus Stewartia was named for Scottish nobleman and botanist John Stuart, who had imported the Japanese stewartia plant to his personal London garden.
Japanese Stewartia. US Department of Agriculture, Forest Service.