Rhododendron orbiculare
ROUND-LEAF RHODODENDRON
Family: Ericaceae
Pronounced: ro-do-DEN-dron or-bik-ew-LAH-ree
Quick Jumps
Growing Guide
Rainy Side Notes
GROWING GUIDE
Origin:
Southwest China
Plant Group:
Shrubs.
Hardiness:
Sunset zones: Not listed.
USDA zones: 7-9.
Heat zones: 9-7.
Mature size:
Height: 3-6 feet (1-2 m) in 10 years. Can reach up to 20 feet (5 m) over time.
Flowering period:
April to May.
Flowering attributes:
Loose trusses carry 7-10 pink flowers that are widely campanulate (bell-shaped) and 2 1/2 inches across.
Leaf attributes:
4-inch long, midgreen, ovate to orbicular leaves are held on the stems with purple petioles. The leaves are almost as wide as they are long.
Growth habit:
Upright.
Light:
Full sun to part shade.
Soil:
Humus rich, well-drained, acidic soil.
Pruning Methods:
Lightly prune for symmetry after the shrub has finished flowering; rarely needs pruning.
Rainy Side Notes
Rhododendrons are so commonly grown here in the Pacific Northwest that sometimes we take a ho-hum attitude — if you've seen one, you've seen them all. However, Rhododendron orbiculare comes along with its untypical rhododendron foliage that its epithet, orbiculare, describes its rounded leaves. In spring, the leaves take a back seat to trusses carrying the hanging, bell-shaped, pink flowers that profusely cover the shrub. The flaking bark is a shade of pale brown.
Orbiculare originally comes from the forests and rocky slopes of Guangxi and Sichuan in China. It grows best in full sun; the shrub grows leggy in the shade. The Royal Horticulture Dictionary claims these shrubs can eventually reach 50 feet (15 m) over time. Was that a typo, or is there an actual specimen that large? The shrub grows more expansive than it is tall. In your Northwest garden, it will most likely reach 20 x 20 feet.
Prune if you live to see it grow beyond that point, or there goes the neighborhood.
Debbie Teashon
Photographed at the Rhododendron Species Foundation Garden.
Gardening for the Homebrewer: Grow and Process Plants for Making Beer, Wine, Gruit, Cider, Perry, and More
By co-authors Debbie Teashon (Rainy Side Gardeners) and Wendy Tweton.