Zinnias will self sow in zones 9 and up. Cover seeds lightly when planting.
Aim to sow 0.25 inches (0.64 cm) deep and try to ensure a gap of at least 11.7 inches (30.0 cm).By our calculations, you should look at sowing Purple Prince about 21 days before your last frost date.
Zinnias are excellent as cut flowers and can be harvested when the flower fully opens.
1 thompson-morgan.com/flowers/flower-seeds/half-hardy-annual-seeds/zinnia-elegans-purple-prince/8719TM