Castor aralia is a large, flowering tree, reaching 60 feet in height and is the only large tree in the ginseng family. In its native eastern Asia, this massive tree can reach 90 to 100 feet tall, is long lived and hardy, and uses its large leaves to cast a dense shade. The leaves are similar to castor beans, hence the common name. Tiny, 1 inch white flowers in dense 1 to 2 foot wide panicles appear in late summer. Fruits are attractive to birds. The genus name comes from the Greek word kalos meaning beautiful and Panax the name of a related genus. The species name means having 7 lobes, a characteristic of the leaves.. Castor aralia does best in deep, moist, fertile, well-drained soils in full sun. It will tolerate light shade and drought, but is generally intolerant of hot and humid summers like those found in the deep South. It will not do well in dry soils. The trunk, branches and the younger stems are armed with spines that tend to disappear from the trunk and larger branches as the tree matures. It has been grown in Europe and the United States as a "tropical" ornamental. It is cold hardy and can be cut back hard each year to control growth. Diseases, Insect Pests, and Other Plant Problems: No known insect or disease problems. Thorns on branches may be a problem.
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.
Full sun (6 or more hours of direct sunlight a day)
Soil texture
Clay; High Organic Matter; Loam (Silt)
Soil pH
Acid (<6.0); Alkaline (>8.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Moist | Occasionally Wet
Mature size
Height: 40 ft. 0 in. - 60 ft. 0 in. | Width: 3 ft. 0 in. - 5 ft. 0 in.
Growth rate
Rapid
Maintenance
Low
Canopy layer
1 - Canopy (>40 ft)
Form & Appearance
Habit / form
Broad; Erect; Oval; Rounded
Texture
Coarse
Foliage
Deciduous
Leaf color
Gold/Yellow; Red/Burgundy
Leaf type
Simple
Leaf arrangement
Alternate
Leaf shape
Palmatifid
Leaf margin
Dentate; Lobed
Leaf feel
Glossy
Leaf size
> 6 inches long, > 6 inches wide
Hairs present
No
Leaf detail
The leaves are from 7 to 12 inches long and wide with 5-7 lobes and range from reddish to yellow. Palmate, toothed, and glossy, the leaves turn dull yellow to red in fall, but are not particularly showy.
Fall color
Gold/Yellow; Red/Burgundy
Flower color
White
Flower value
Showy
Flower form
Panicle
Flower size
< 1 inch
Flower detail
Tiny white flowers appear profusely in large, terminal, umbel-like panicles (12 to 24 inches wide) in late summer.
Bloom time
Summer
Fruit color
Black
Fruit type
Drupe
Fruit value
Showy
Fruit size
< 1 inch long, < 1 inch wide
Fruit detail
Tiny black fruits in compound clusters ripen in fall.
Bark color
Dark Gray
Bark detail
Dark gray bark is ridged and furrowed.
Wildlife & Ecology
Native status
Non-native
Origin
East Asia: Japan, Central China, Tibet, Mongolia, Korea
Wildlife value
Birds eat the fruit. Flowers attract pollinators.
Attracts
Bees; Pollinators; Songbirds
Food & Medicine
Harvest time
Fall
Fruit type
Drupe
Landscape Use
Landscape location
Woodland
Landscape theme
Shade Garden
Design feature
Flowering Tree; Shade Tree
Garden tags
#deciduous #large tree #heat intolerant #humidity intolerant #drought tolerant #spines #shade tree #thorns #large leaves