There's no mistaking the colour and stature of annual Zinnias.
Season & Zone
Exposure: Full sun
Direct sow after last frost, in April and May on the coast. Zinnias don't transplant well, but you can try starting some indoors in peat or coir pots 6-8 weeks before planting out. Maintain a soil temperature of 21-26°C (70-80°F). Seeds should germinate in 5-24 days.
Just cover Zinnia seeds, and aim for a final spacing of 25-30cm (10-12") between plants.
Grow in average, well-drained garden soil, but dig in a generous amount of well-rotted manure the previous fall. Pinch off growing tips early in the season for bushier growth. Water regularly, keeping leaves as dry as possible. Deadhead regularly. Feed once in early spring, and again once flowering has begun.