Common Name: Chinese rhubarb
Type: Herbaceous perennial
Family: Polygonaceae
Native Range: Northwestern China
Zone: 5 to 7
Height: 6.00 to 10.00 feet
Spread: 4.00 to 6.00 feet
Bloom Time: May to July
Bloom Description: Pink to red
Sun: Full sun to part shade
Water: Medium
Maintenance: Low
Flower: Showy
Culture
Easily grown in organically rich, moderately fertile, evenly moist but well-drained soils in full sun to part shade. Plants appreciate some part shade in the heat of the day in hot summer climates. Plants are more sensitive to drought and heat than common rhubarb. Best growth is in USDA Zones 5-7. Plants dislike the hot summer temperatures of the deep South in Zones 8-9. Mulch to keep roots cool and retain moisture. Best propagated by division of rhizomes in early spring. Plant seed in fall.
Noteworthy Characteristics
Rheum palmatum, commonly called Chinese rhubarb, is a rhizomatous perennial with a large rootstock and thick leafstalks. It typically grows to 6-10' tall. It is native to China and Tibet. Unlike its culinary cousin (Rheum x hybridum) which is grown as a vegetable for harvest of its edible leaf stalks, Chinese rhubarb is primarily grown as (a) an ornamental for enjoyment of its huge rounded leaves and feathery plumes of summer flowers and/or (b) a medicinal plant. Round, palmately-lobed, dark green basal leaves (to 2-3' wide) form a large domed foliage mound to 4-6' wide. Each leaf has 3-5 ribs. Large plumes of tiny, 6-tepaled, pink to red flowers bloom in branched terminal panicles (to 2' long) rising above the foliage to 7' tall on thick, hollow flowering stems. The roots are used in Chinese medicine for treatment of a variety of medical conditions including constipation, diarrhea, peptic ulcers, immunosuppression, high blood pressure and cancer.
Genus name comes from the Greek name for the roots and rhizomes imported from Iran (or genus name comes from the Greek word rha which is the ancient Greek name for the common rhubarb).
Specific epithet refers to the palmate leaves.
Problems
No serious insect or disease problems. Crown rot is a potential problem, particularly if soils drain poorly. Also susceptible to borers, beetles or rhubarb curculio. Leaf spots can be a problem, but will usually not affect the quality of the crop.
Uses
Bold ornamental specimen or accent. Needs a large growing space. Borders. Water margins of streams or ponds. Herbal/conventional medicinal uses.