Celastrus orbiculatus [see-LAS-trus, or-bee-kul-AY-tus] is a perennial climbing and deciduous woody vine belonging to the Celastraceae family, also known as the staff-tree family.
The plant is native to China, Korea, and Japan, but it is so widely found in North America, where it was introduced as an ornamental plant around 1860, it is considered an invasive species in the eastern parts of the continent.
You may also hear it called by its common name including:
- Oriental Bittersweet vine
- Chinese Bittersweet
- Asian Bittersweet
- Asiatic Bittersweet
- Round-leave Bittersweet
- Climbing Spindleberry
Celastrus Orbiculatus Care
Size & Growth
The vines of undemanding and hardy Celastrus orbiculatus are thin and long.
While they can grow up to 60’ feet in length, their maximum diameter is only 4” inches.
Celastrus orbiculatus is a rapidly growing plant forming thickets when it grows itself.
But, when there is support, it climbs by twining around it.
The plant is often considered an ecological threat because it not only outcompetes and covers other vegetations in its surroundings but can cause the death of large trees by girdling them.
Flowering and Fragrance
Celastrus orbiculatus produces small, axillary, inconspicuous, greenish-white flowers from May to early June.
The flowers grow in small clusters; there are about 3 to 7 flowers in an inflorescence.
Light & Temperature
Celastrus orbiculatus prefers full sun and yields more flowers when exposed to the sunlight.
However, since it is a hardy plant, it can tolerate partial shade.
Watering and Feeding
Celastrus orbiculatus needs a moderate amount of water for proper growth.
When grown in the house garden, water the plant regularly; however, be careful not to overwater.
Soil & Transplanting
Oriental Bittersweet can grow in all types of soil, but it thrives in light sandy and medium loamy soils.
However, since it grows too fast, it is sometimes recommended to plant it in nutritionally poor or lean soil as it becomes too expansive in the fertile soil.
The plant can tolerate a wide range of pH; it easily grows in neutral and acidic soils but prefers moist and well-drained soil.
Grooming and Maintenance
Celastrus orbiculatus grows so rapidly it often becomes hard to control it.
Cutting, which are used for growth control in different plants, is not alone effective in the case of this vine.
It stimulates further growth and makes the vine re-sprout ten folds.
In house gardens, the best way to control the vine growth is to cut it back to the ground and immediately apply an herbicide (as per the directions on the label) on the cut stem.
How to Propagate Chinese Bittersweet
Celastrus orbiculatus is propagated by seeds, wood cuttings, root cuttings, and layering.
In natural conditions, the seeds are dispersed by birds and animals attracted to the fruit due to their bright scarlet color.
When propagating yourself, collect the seeds when they are ripe and store them in dry sand until February.
While the rate of seed germination is high, cold stratification for three months ensures an even higher rate of germination.
Make sure to remove the fruit flesh from the seeds while storing as it inhibits germination.
When it’s time to sow, prick the seedlings in separate pots and place the pots in a warm greenhouse, at least throughout the first winter season.
In late spring or early summer, shift the plants to their permanent positions.
For propagation through the root, take 1” inch long and ¼” inch thick cuttings in December and plant them horizontally in pots.
The best time to take wood cuttings is July/August whereas August is the best time to propagate through layering.
Make sure to choose half-ripe wood and the growth of the current season for propagation through wood cutting and layering respectively.
Oriental Bittersweet Vine Pest or Diseases
The vines of Celastrus orbiculatus rarely get affected by diseases and pests.
In some areas, however, it can get damaged by the two-marked treehoppers and the euonymus scale.
Climbing Spindleberry Uses
Celastrus orbiculatus is largely grown as an ornamental vine.
While it will cover fences and outdoor structures like pergolas, arbors, and arches, the plant is also grown alongside roads and highways to create noise barriers.
In some parts of the world, the plant is also used for medicinal purposes.