Growing:

Sunflowers grow best in locations with direct sun (6 to 8 hours per day); they prefer long, hot summers to flower well. They have long tap roots which need to stretch out so the plants prefer well-dug, loose, well-draining soil; in preparing a bed, dig down 2 feet in depth and about 3 feet across to ensure the soil isn't too compact. You should find a well-drained location, and prepare your soil by digging an area of about 2-3 feet in circumference to a depth of about 2 feet. Though they're not too fussy, sunflowers thrive in slightly acidic to somewhat alkaline (pH 6.0 to 7.5).

Sunflowers are heavy feeders so the soil needs to be nutrient-rich with organic matter or composted (aged) manure. Or, work in a slow release granular fertilizer 8 inches deep into your soil. If possible, put seeds in a spot that is sheltered from strong winds, perhaps along a fence or near a building.

It's best to sow sunflower seeds directly into the soil after the danger of spring frost is past. Ideally, the soil temperature has reached 55 to 60 degrees F. Give plants plenty of room, especially for low-growing varieties that will branch out. Make rows about 30 inches apart. (For very small varieties, plant closer together.) Plant the large seeds no more than 1 inch deep about 6 inches apart after it has thoroughly warmed, from mid-April to late May. You can plant multiple seeds and thin them to the strongest contenders when the plants are six inches tall. A light application of fertilizer mixed in at planting time will encourage strong root growth to protect them from blowing over in the wind. Experiment with plantings staggered over 5 to 6 weeks to keep enjoying continuous blooms.