The National Garden Bureau has declared 2021 as the Year of the Sunflower.
Who doesn’t love this bright and cheerful flower?
When you say “sunflower” most people think of the annual plant with the giant yellow flowers. Sometimes you will see a whole field of them.
Sunflowers belong in the genus Helianthus, derived from the Greek “helios” meaning sun and “anthos” meaning flower. Since the flowers are yellow and look like the sun, the name seems obvious.
The common sunflower (Helianthus annuus) is native to northern Mexico, the western United States and Canada. Plants were cultivated as far back as 5,000 years ago by Native Americans.
Today sunflowers are grown as ornamental flowers, for birdseed, livestock feed, oil, snack food and they can even be processed into a sunflower butter. Since they are relatively easy to grow, sunflowers are a great plant for children to grow.
If you feed sunflower seed to the birds, you may have a few surprise sunflowers popping up in odd places.
Typically, sunflower plants have a large, stout central stem that is covered with stiff hairs. The large leaves can be 8 inches long and 6 inches wide.
Annual sunflowers can grow anywhere from 3 to 9 feet tall — or more, depending on the variety.
Plant breeders have been busy with sunflowers creating many varieties. Some are the traditional yellow blooms, but you can also find flowers that are shades of yellow, red, bronze, burgundy, white and even bicolor flowers.
Dwarf varieties are considered to be 1 to 3 feet tall while mammoth sunflowers can grow 15 feet tall with flowers a foot in diameter. Pollenless varieties appeared on the market in 1988 and they are great for flower arrangements.
Annual sunflowers are easy to grow. They need a spot that has full sun and prefer moist, well-drained loamy soil.
They will tolerate other soils that are drier. They do need regular deep watering before, during, and after flowering.
There is no need to start seeds indoors, and you can plant directly in the garden after the last frost date in your area. Plants will grow quickly.
If you are growing the taller varieties, you may need to stake them or grow them where they are protected from strong winds.
Generally, you don’t need to fertilize them, but a slow-release granular fertilizer can promote larger flowers in poor soil. Don’t over fertilize as too much nitrogen will inhibit flowering.
Sunflowers bloom during the peak of summer into fall. Sunflowers need between 45 and 100 days from seed to flower depending on the variety.
Plant about 1 inch deep, spacing depends on the variety. Check the seed packet for specific planting instructions.
If space is an issue, try planting a dwarf variety in a large container.
You might have to protect your seeds from birds, chipmunks, squirrels, and mice. Woodchucks, deer and rabbits like newly sprouted seedlings.
Sunflowers are great for attracting pollinators and beneficial insects to your garden.
Did you know that there are also perennial sunflowers that you can add to your garden and landscape? Many are native and support a wide variety of wildlife.
Birds love the seeds. The flowers support a variety of bees, butterflies, and other insects while the foliage hosts caterpillars.
If you want to support native insects include plants from the Helianthus genus plus aster and goldenrods. Those are the top three genus of herbaceous plants that support the most species of native butterflies and moths.
Many of our native sunflowers spread by rhizomes, which means that they may be too aggressive for many gardens, especially smaller gardens. They would be best suited to areas where they can naturalize and create a sea of yellow blooms.
Growing up to 10 feet tall, the very showy Maximilian sunflower (Helianthus maximiliani) towers above its garden buddies when in bloom. Native to central North America, Maximilian sunflower is part of the tall grass prairie ecosystem.
The 2 to 3-inch diameter yellow blooms light up the garden starting late summer and bloom for about a month. The narrow 12-inch-long leaves are a greyish green or light green color.
Grow Maximilian sunflower in full sun. It tolerates a wide variety of soils and is drought tolerant.
The long-lived plants need plenty of room to grow and spread. It is not a plant for small gardens. It will probably self-seed as it is easily grown from seed.
Native to the eastern United States, the Woodland Sunflower (Helianthus divaricatus) has 2 inch wide bright yellow flowers with a slightly darker yellow center. Plants bloom July to September and grow 2 to 6 feet tall.
Woodland sunflower will grow in average to dry soils in part shade. Plants tolerate growing near black walnut trees.
The flowers can be used for cut flowers.
Small Woodland Sunflower (Helianthus microcephalus) is also native to the eastern United States. Its cheerful yellow flowers are amongst the smallest of the genus at about an inch wide.
The flower clusters have a fairly long bloom time, from mid-summer into fall. Deadheading spent flowers will promote more blooms.
This sunflower can grow in full sun to filtered shade. It can take moist to dry soils.
At 4 to 6 feet tall with a 3 foot spread, it is perfect for the back of a perennial border or naturalizing. Divide plants every three to four years in the spring.
Have a wet spot in your yard? Try Swamp Sunflower (Helianthus angustifolius) which is the latest blooming of the native sunflowers, flowering in the fall until frost.
The bright yellow starry flowers are 2 to 3 inches across and grow on 6 foot tall stems. Unlike its fellow native sunflowers, it grows in a clump, spreading gradually rather than running through the garden.
Native to the eastern United States it would be a good plant for a rain garden as it prefers sunny, moist habitats. It can take drier soils but may need supplemental watering.
Perennial or annual, sunflowers are a great addition to any landscape for their cheery blooms.
Have a gardening question? The Master Gardener office is open.
Please wear a mask when visiting the Cornell Cooperative Extension office and check in at the reception window.
Master Gardener volunteers are normally in the office Monday through Friday, from 10 a.m. until noon. You can stop in at the CCE office at 420 E. Main St. in Batavia, call (585) 343-3040, ext. 127, or e-mail it at: email@example.com.
Join us at noon Monday via Zoom for “Native Plants for Butterflies.”
We will discuss the components of a butterfly garden focusing on aspects that support a butterfly’s life cycle including nectar sources, host plant species, and shelter. We will highlight several butterfly species endemic to western New York and the native plants that support their life cycle.
The program is free. Register for your Zoom link at http://genesee.cce.cornell.edu/events