|This a showy and dependable edging plant that may be categorized as an annual or perennial. Compact and trailing growth habit with leafy, branching stems covered in 2-lipped, purple flowers (three quarters of an inch across), from summer to frost. Trailing varieties are excellent in large planters or smaller pots. Will live through the winter in mild areas. Be patient with sown seeds as it can take up to 2 months for them to become transplanting size. Prefers moist, rich soil and will continue to self-sow once established.