Pronounciation: Ru-EL-lee-a SIM-plex

Hardiness zones
Sunset 12-24
USDA 8 (freeze damage), 9-11

Landscape Use: Foliar and floral accent and/or filler shrub for landscape borders, even passive streetscape bioswales. This is a versatile shrub for use in mesic and oasis landscape design themes. It works especially well with Spanish architectural styles.

Form & Character: Shrubby, spreading, and a bit unruly, dark purple cast, succulent appearance, aggressive, tropical.

Growth Habit: Evergreen, mostly herbaceous, perennial broadleaf shrub, quick to establish and grow to 3- to 6-feet tall with equal spread. Becomes lush and full with age. Spreads moderately by underground rhizomes to form clumping colonies.

Foliage/Texture: Leaves elongate-linear to 12-inches long, much shorter if plants are grown in dry site, entire to undulate, petioles to 3/4-inch long; medium texture.

Flowers & Fruits: Flowers terminal on elongated, axillary peduncles, corolla to 1.5-inches long, tube about 0.5-inches across, expanded above, lobes rounded, flower colors are mostly violet purple, but also white or pink. Purple ruellia flowers attract bees. Fruits are inconspicuous brown achenes; however fruits eject seeds up to 10 feet from the plant when sprayed with a hose, or rained upon (sounds like Rice Krispies when first doused with milk).

Seasonal Color: Deep purple foliage is colorful year round. In Phoenix, purple, white, or pink, flowers are produced in all but coldest but winter.

Temperature: Freeze intolerant, but heat loving, except for dwarf cultivars which might need some protection from west summer exposures when young.

Light: Full sun to partial shade

Soil: Tolerant of some alkalinity, but prefers acidic to neutral soils.

Watering: This shrub is very responsive to landscape irrigation. Thrives with regular and frequent irrigations especially during summer. How water is delivered effects its habit of growth, specifically the vigor of growing rhizomes and plant spread. In flood irrigated properties, purple ruellia will become very aggressive and can literally "take over" a residential yardscape.

Pruning: Prune to shape anytime. Except for dwarf cultivars, often headed back severely to the ground in winter.

Propagation: Cutting, seed

Disease and pests: Spider mites

Additional comments: Best used with drip irrigation. In flood irrigated landscapes, this shrub might become invasive. Works well with Tecoma stans, Bougainvillea, and many others with complementary flower colors for a tropical landscape feel. 'Chi Chi' is a popular cultivar with pink flowers. Another popular dwarf cultivar with violet purple flowers is 'Katie'. Finally, a dwarf cultivar with white flowers is called 'Alba'.