Type of plant: Perennial in warm zones; grown as annual elsewhere
Height: Several inches to 1 foot tall
Width: 12-18 inches wide
Bloom color: Many colors: Red, white, pink, violet, purple, coral.
Bloom time: In frost-free zones, they bloom 365 days a year.
Scent: None
Sun/shade: Part or full shade
Moisture: Regular water
Problems:
Purchased: Any local nursery
Planted: Best planted in spring so they have a chance to get established before cold temperatures in fall and winter; this will greatly improve their chances of living over winter.
Conditions: In amended clay soil in part shade.
Other comments: They just continue to grow and bloom year after year in frost-free winters, though they are at their best in the warm temperatures of spring and summer into fall. No dead-heading is necessary, ever. I give them a periodic "hair cut" when the stems get long and leggy once or twice a year by cutting back the stems to about 5-6 inches; new growth quickly returns. Excellent year-round color; the white ones are bright in the shade. Many people think they are too common and perhaps rightly so (especially if mass planted), but you can't beat them for spots of bright color and ease of care.