Sow direct where they are to grow when soil is warm, or in trays of Yates Seed Raising Mix. Firm down, keep moist through germination and transplant when seedlings are large enough to handle.
Choose a well-drained, sunny, wind-sheltered position. Add compost and Yates Blood & Bone before planting and fertilise regularly with Yates Thrive Soluble Flower & Fruit Plant Food. Protect from snails and slugs with Yates Blitzem.
Transplant carefully as seedlings resent root disturbance. Mulch around base of plants to retain soil moisture. Pinching out first buds will encourage branching. Remove spent flowers to prolong display.