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: Evergreen shrub, gently sprawls, brittle, sometimes sparse
Growth Habit: Slow to moderate growth rate to 5' height with greater spread depending on cultivar and soil conditions, watering, fertility, etc.
Foliage/texture: Classic cordate (heart shaped) leaves, alternate, thick and almost succulent with prominent palmate veination much like a miniature Algerian ivy leaf (Hedera canariensis), leaves born on relatively thick and chunky stems with lenticels; medium texture
Flowers & fruits: Bright lemon-yellow petaled, open face flowers, 2" in width with five red dots, from late spring to the fall; fruit much like cotton balls. Closely related to Gossypium hirsutum (cotton).
Seasonal color: Blue flowers in late winter
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: Highly respondedt to irrigation. Too much and it looks rank. Too little and it looks sparse. Infrequent deep irrigations are best, especially during summer months.
Pruning: Head back relatively infrequently.
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. Put it in your desert yard in its desert spot with desert poor soil and it will transform into a very tough and dependable native plant.
