Sunflowers—the signature flower of the state of Kansas can get up to twenty feet tall with blooms reaching two feet across. They have been used for everything from ground seed flour for bread by the Native Americans to dyes for clothing and the body to a snakebite remedy. These perky plants always point their blooms toward the sun so plan on that when you decide on growing sunflowers. That in mind, the taller (but not tallest) varieties make splendid backdrops for tall wild flower arrangements while miniature varieties make good borders.
Tips for Growing Sunflowers:
Because sunflowers are rapid growers their seeds are best sown directly into your outdoor garden. Once planted, they should be covered with a screen, as the birds love them. As a matter of fact over half the people who are growing sunflowers do so in order to feed the birds. If you do need to start them early because of growing season use a peat pot and transfer when they have four leaves, pot and all. Soil should be about 50 degrees or above. Start them several weeks before your last expected frost.
Sunflowers prefer a soil that is on the rich side in a sunny spot. Because they can get so tall, most people have a particular out of the way, but visible, location for them. The taller the variety the richer the soil should be. Use regular soil rather than a sandy one when planting sunflowers as it will be important for your plants to be able to spread their roots out and grip the ground. It will be necessary for them to keep their tall structure upright
Before starting consider turning the soil at least a foot down to prepare for these giants. Space the giant ones about 3’ apart in rows or a grouping with plants of different heights. When planning for planting sunflowers, grouping them actually helps stabilize the tall thin stems. The medium varieties should be planted 2’ apart and the miniatures about a foot. Do to the many varieties of sunflowers patterns including several of the varieties are very attractive.
How to Grow Sunflowers:
Sunflowers take about 75 days to mature—up to 90 for some varieties. Be sure to read the label of your seed packet to be sure. Fertilize sunflowers when you take care of the rest of your garden—and an extra bit of potassium and phosphorus will help them develop big, beautiful flower heads. A good blend when considering how to grow sunflowers is 10-15-10 (nitrogen-phosphorus-potassium, in that order—which is universal).
Sunflowers can tolerate dry spells as readily as being overwatered. They do not tolerate either to an extreme however. And too much water could result in a weakening in the root/soil relationship of the plant.
Sunflowers are relatively hardy. The ants may seem like they are attaching them but they just enjoy the nectar. They have few other pest or diseases that affect them but the birds and squirrels will fight you tooth and nail for their seeds. Actually sunflowers help control aphid damage and they attract humming birds which in turn love whiteflies.