Choose a site with average to poor, well-drained soil in full sun.
Plant seeds directly in soil after your region's last average frost date. Or start seeds indoors six to eight weeks earlier.
Thin plants to about 2 feet apart.
Keep soil evenly moist, but don't overwater - this flower likes it a little on the dry side.
Trim faded flowers to promote longer blooming.
Fertilize every 8 to 10 weeks, or work in a slow-release fertilizer (or plenty of compost) at planting time.
Tear out and discard plants in fall, after frost fells them.