A cheerful summertime bloomer, sunflowers celebrate the longest days of the growing season. Plant seeds every two weeks or so beginning in late spring, and you can enjoy fresh crops of annual sunflowers until the first frost. A quick look at the seed rack at your local nursery or an online search will reveal a host of colorful sunflowers, ranging from petite 2-foot-tall varieties to giants that stand 10 feet tall or more.
A cinch to grow from seed, sunflowers can be planted almost anywhere. For the cost of a packet of seeds you can enjoy a bevy of these summertime beauties in the cutting garden, alongside a lackluster garage wall, near a mailbox, at the back of a cottage garden, or near your front door. If a site has full sun and well-drained soil, you can grow sunflowers. Use small varieties in landscape beds for a touch of whimsy in midsummer. Dress up a drab fence with three rows of sunflowers, beginning with a knee-high variety up front, a midsize variety in the middle, and a mammoth variety next to the fence. Have fun with the multitude of sunflowers on the market.
Sunflower Care Must-Knows
Sunflowers thrive in full sun and moist, well-drained soil. Start plants from seed indoors six to eight weeks before the last frost or sow them directly in the garden once soil has warmed in spring. In the garden, plant seeds about 1 inch deep and about 6 inches apart. Water as needed to keep the soil moist. Seedlings emerge in about two weeks.
Related: Annual Care Guide
When seedlings are about 3 inches tall, thin them so there is one plant every 12 to 18 inches. Well-spaced seedlings are key to strong, upright sunflowers later in the season. Plants will develop weak and wobbly stems if they grow too closely together, or if they don't get enough light.
Sunflower Seed Harvest Tips
A few varieties of sunflowers are grown for their edible seeds. 'Giant Grey Stripe' and 'Mammoth Russian' are two popular varieties. These sunflowers form a single large flower head atop a stem that may reach 10 feet or more. Allow the seed heads of these varieties to start to dry and turn yellow before cutting the head off the stalk. Store the head in a dry, well-ventilated place where the seeds can fully mature. Seeds are ready to store or eat when the disk at the back of the flower has turned dark brown.
More Varieties of Sunflower, Annual
This type of Helianthus bears large reddish-orange flowers on 8-foot-tall plants with multiple branches.
Sunflower, Annual Companion Plants
Plant a castor bean and then stand back. This is one of the fastest-growing, giant annuals in the garden, rivaled only perhaps by giant sunflower. By midsummer, you'll have a huge (it can hit up to 20 feet) tropical plant sporting burgundy foliage. It's a great plant to grow with kids. Be careful, though. The seeds are extremely toxic. Wait to plant it outdoors after all danger of frost has passed; castor bean hates cool weather and won't grow well until temperatures heat up in summer.
Try this delightful flower to grow something different and striking in your garden. You don't see this old-fashioned plant as often as you used to, but when you do it is spectacular. Chains of delicate pink flowers hang down from tall stems that can reach 12 or more feet tall on this fast-growing annual. It's great for creating a quick privacy screen or make a bold statement in big containers. Kiss-me-over-the-garden-gate can self-seed in the garden.
Want fast color for just pennies? Plant zinnias! A packet of seeds will fill an area with gorgeous flowers in an amazing array of shapes and colors—even green! And it will happen in just weeks. There are dwarf types of zinnias, tall types, quill-leaf cactus types, spider types, multicolor, special seed blends for cutting, special blends for attracting butterflies, and more. Zinnias are so highly attractive to butterflies that you can count on having these fluttering guests dining in your garden every afternoon. But to attract the most, plant lots of tall, red or hot pink zinnias in a large patch. 'Big Red' is especially nice for this, and the flowers are outstanding, excellent for cutting. Zinnias grow quickly from seed sown right in the ground and do best in full sun with dry to well-drained soil.