Sunflowers come in a number of different varieties, colors and sizes to fit into any size garden or yard. Gardeners often grow sunflowers specifically for harvesting the seeds produced. You can use the sunflower seeds to feed wildlife or for eating yourself. Sunflower (Helianthus annuus) is native to North America, and can grow to heights reaching 8 to 15 feet tall with flowerheads ranging from 8 to 15 inches wide, according to the Floridata.
Select an area to grow sunflower plants that offers full sun and well-draining soil. Sunflower plants grown in partially shady areas could easily topple over trying to reach the sun, according to Floridata. Plan enough room for spacing taller varieties of sunflower plants 2 to 3 feet apart, and smaller varieties 1 foot apart. Space rows at least 3 feet apart, if growing more than one row.
Cultivate the area selected to a depth of 1 foot (or more), after the last chance of frost has passed. Add compost or other organic matter, and mix it into the soil.
Sow the sunflower seeds 1 inch deep for large types, and ½-inch deep for smaller varieties. Put more than one seed per hole, or space the sunflower seeds closer together, and thin out the stronger seedlings after two weeks.
Water the newly planted seeds. The sunflower seeds should sprout in about a week. Continue to water the sunflower seeds with 1 inch of water weekly, unless rainfall supplies it.
Cover the area around the sunflower seedlings with 3 to 4 inches of mulch. This prevents weeds from growing, as well as keeps the soil moist and cool. Hand-pull weeds, if mulch is not used.