Design

Yellow Thread Rohdea Is a Rare Perennial Jewel for Shady Nooks and Crannies

Fine Gardening – Issue 215
Rohdea pachynema

While some may be familiar with Japanese sacred lily (Rohdea japonica, Zones 6–10), Rohdea pachynema is an uncommon species that is indeed a Rohdea less traveled. Found only in the Chinese provinces of Yunnan and Sichuan, it is an intriguing member of the Asparagaceae family that is slowly becoming more available to gardeners. It was formerly known as Campylandra sinensis or C. pachynema, but recent DNA work has moved it into the genus Rohdea, whose name commemorates German botanist Michael Rohde. We can find no documented common name for this species, so we have dubbed it “yellow thread rohdea” since pachynema means “thick thread” (referring to the colored central stripe on
the leaves). 

We suspect that most if not all of the plants of yellow thread rohdea in cultivation are derived from the same population on the flanks of Sichuan’s Luoji Mountain. Bill McNamara of Quarryhill Botanical Garden (now Sonoma Botanical Garden) in California was likely the first to introduce this species to North America. During a visit to Quarryhill some years ago, we were instantly smitten upon seeing Bill’s collection of this beautiful and unfamiliar plant. Our shameless begging worked, and we were gifted a piece of this treasure. 

Later, we avidly read Bill’s account of his botanical expedition to Luoji Mountain
and then made our own visit to that same 14,300-foot peak. It was like coming across an old friend along the trail when we saw yellow thread rohdea growing among culms of bamboo. Other collectors have been to the same mountain on the same trail and undoubtedly availed themselves of this impossible-to-miss colony.

Yellow thread rohdea has durable, darkly evergreen, narrow leaves reaching
18 inches long or more that gently arch and are highlighted by a pale yellow midrib stripe along their length. It does flower, albeit the blooms are more of a curious green sculptural element than something to be considered for a bouquet—which makes one appreciate the amber tones the flowers take on as they age. Looking at the glossy exotic leaves and overall gestalt, we drew upon our decades of plant hunting and growing rare plants to conclude that this refined rohdea cannot be very hardy. To our surprise, it trash-talked our 10°F dips in winter like it ain’t no thang.
It is likely cold hardy to Zone 6, though it may sustain some winter leaf damage.

A rhizomatous perennial, yellow thread rohdea spreads nonaggressively but steadily, increasing appropriately as it intuits your desire for “more, please” once
you come to appreciate its understated tasteful beauty and its zero to minimal
maintenance needs. Deer don’t seem to notice it, and it has no notable pest or
disease issues. With each passing year, we value all the more those plants that are largely self-maintaining, and yellow thread rohdea is just such a plant.

 

Yellow thread rohdea

Rohdea pachynema

Thread Rohdea illustrationZones: 7–10

Conditions: Partial to full shade; rich, moist to moderately dry soil

Native range: China

Sources: 

Far Reaches Farm, Port Townsend, WA 360-385-5114; farreachesfarm.com

Keeping It Green Nursery, Stanwood, WA 360-652-1779; keepingitgreennursery.com

 


Kelly Dodson and Sue Milliken grow some of the coolest plants on the planet at Far Reaches Farm Nursery and Far Reaches Botanical Conservancy in Port Townsend, Washington.

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