Ruellia simplex 'Katie'
Light: Full sun to partial shade; afternoon shade is beneficial in Phoenix, especially near heat-reflecting walls.
Water: Moderate water for best flowering; water deeply when the upper 1–2 inches of soil dry. Established plants tolerate short dry periods but need regular irrigation during extreme summer heat.
Soil: Adaptable to most soils, including alkaline soil; well-drained soil enriched with compost supports best growth.
Mature size: 8–12 inches tall and 12–18 inches wide; colonies can spread farther over time.
Bloom: Spring through fall, often into early winter in frost-protected locations; individual flowers last one day.
Evergreen / deciduous: Evergreen to semi-evergreen in mild winters; frost may kill foliage back, with regrowth from roots in spring.
Growth rate: Moderate to fast during warm weather with adequate moisture.