June 9, 2007
Plant of the Week
This compact upright rounded, evergreen shrub is covered during most of the year with small, very showy, yellow flowers. The loose, open natural growth habit is ideal for informal plantings but it will need some pruning to keep from being too leggy. It can be sheared into a more formal hedge and can he used for topiary, but some flowers will be trimmed of at each pruning. Sheared plants often thin out at the bottom. To help prevent this, keep the bottom of a hedge slightly wider than the top to allow sunlight to reach the lower foliage.
Scientific Name: Galphimia glauca Pronunciation: gal-FlM-ee-uh GLOCK-uh
Common name(s): Thryallis, Rain-of-Gold
Plant type: shrub
USDA hardiness zones: 9B through 11
Planting month for zone 9: year round
Planting month for zone 10 and 11: year round
Origin: not native to North America
Uses: border: mass planting: specimen: container or above-ground planter.
Invasive potential: not known to be invasive
Pest resistance: no serious pests are normally seen on the plant
Use and Management:
Full sun is needed for best appearances and flowering, but Thryallis can tolerate some shade. Flowering may be sparser without a full day of sun. Plant three to five feet apart in shrub border or in any mass planting. Plants are killed to the ground at about 25-degrees F. but quickly re-grow in the spring in USDA hardiness Zones 8b and 9.
Thryallis is propagated by seeds, sown while still green, or by tender softwood cuttings in summer. Seedlings will bloom when one-foot-tall and six-months-old.
Thryallis is pest-free, only occasionally being bothered by caterpillars and mites. DEER WILL NOT EAT THRYALLIS.
Remember, Learn and Have Fun!
David Rodriguez is County Extension Agent-Horticulture, Bexar County. For more information, call the Master Gardener ‘Hotline’ at (210) 467-6575 or visit our County Extension website at https://bexar-tx.tamu.edu, click under Horticulture and Gardening.