Pronounciation: Gos-SIP-ee-um hark-nes-SEE-ii
Hardiness zones:
Sunset 12-24
USDA 9-11 (best in semi arid to arid zones)
Landscape Use: Filler shrub for xeric landscapes, rock gardens, native desert gardens, hummingbird gardens.
Form & Character: Rounded, dome like, gently sprawling, brittle, sometimes sparse and open.
Growth Habit: Evergreen, woody, broadleaf perennial shrub, slow to moderate growth rate to 5-feet tall (often less) with greater spread depending on soil conditions and watering.
Foliage/Texture: Classic cordate (heart shaped) leaves, alternate, thick and almost succulent with prominent palmate veination [much like miniature Algerian ivy (Hedera canariensis) leaves], leaves born on relatively thick and chunky gray stems with lenticels; medium texture.
Flowers & Fruits: Bright lemon-yellow petaled, open face flowers, 2-inches wide with five red dots, from late spring to the fall; fruit much like cotton balls. Closely related to Gossypium hirsutum (cotton).
Seasonal Color: Subtle yellow blooms during mostly spring and fall.
Temperature: Heat tolerant, cold hardy to 25oF.
Light: Full sun, though avoid highly reflective western exposures as leaves will turn chlorotic yellow.
Soil: Actually prefers poor soils, salt tolerant. Avoid excessive amount amounts of organic matter amendments.
Watering: San Marcos hibiscus responds well to irrigation, but too much watering can cause it to look rank. Too little water though and the foliage looks sparse. So, infrequent and deep irrigations are best, especially during the hot Phoenix summer months.
Pruning: Head back relatively infrequently, optimally in early spring.
Propagation: Seed
Disease and Pests: None
Additional comments: San Marcos hibiscus is a great, but infrequently used spreading shrub for native desert gardens. Don't be dismayed by how poorly this desert native shrub does when growing in a nursery container with an abundance of organic matter substrate, or how slowly it establishes once planted into the landscape from container. Put it in your desert yard in its favorite desert spot with desert poor soil and over time it will transform into a very tough, dependable and lovely-looking, native plant.
