LSU AgCenter Horticulturist
Perhaps one of the most brilliant and uplifting of flowers is the sunflower. Native to North America and made popular throughout Europe, this plant has a long history. Helen Keller once said, “Keep your face to the sunshine and you cannot see the shadow. It’s what sunflowers do.”
According to the National Sunflower Association, the sunflower was a common crop grown by American Indian tribes. The plant was first cultivated in present-day Arizona and New Mexico about 3000 B.C. Some archaeologists believe the sunflower was domesticated before corn.
Today, sunflowers are grown as a crop for seed, cooking oil and making flour. They are also grown as cut flowers and can be used in the landscape as an ornamental selection. The National Garden Bureau has designated 2021 as year of the sunflower.
Sunflowers can be either annual (Helianthus annuus) or perennial (Helianthus maximiliani). The most commonly known types are annual and are single stemmed. There also are both pollen and pollen-free varieties. Pollen-free varieties have been bred to be sterile to extend the vase life of the cut flowers and for their clean appearance. It’s also good for allergy sufferers. Some pollen-free sunflowers are Moulin Rouge, ProCut series, Sunbuzz, Sunrich series and the Vincent series.
Pollen-producing sunflowers are excellent for those gardeners who ae looking to support pollinators such as bees, butterflies, beetles and moths. Some great pollen-producing selections for your garden are Soraya, Ring of Fire and Valentine.
Sunflowers also can be grown for edible seeds. Some examples are Feed the Birds, Mongolian Giant, Skyscraper, Super Snack Mix and Titan. Seeds are ready to harvest once the petals have withered and the seeds can be seen.
Tall, single-stemmed sunflowers are best for cut flowers. Some single-stem sunflowers are the ProCut series, Sunrich series and Vincent series. To extend the life of your cut sunflowers, cut when the petals just begin to open in the early morning before the heat of the day. Remove the leaves below the water line and place in fresh water. Sunflowers need a great deal of water, so check it regularly and refill as needed. It is best to change water daily.
Branching varieties produce flowers on shorter, branched stems. Some examples are Autumn Beauty Mix, Soraya, SunBuzz, Sunfinity, SunBelievable and, lastly, a Louisiana Super Plant for 2021, Suncredible.
Suncredible is an annual, ever-blooming, branched sunflower with a bush-like habit. It grows up to 4 feet with a spread of 2 feet. Blooms are up to 4 inches across and do not require deadheading. This sunflower blooms for weeks, makes a great cut flower and the pollinators love it, especially the bees and butterflies. It adds a perfect pop of yellow to your fall garden.
Suncredible grows best in full sun and can tolerate a range of soils. It is drought and heat tolerant once established. It has no real disease or pest issues. It can be used in both the landscape and container plantings. To encourage vigorous growth, use a controlled-release fertilizer at the time planting and again in late summer or early fall. A mass planting makes a great focal point in the garden.
People just love sunflowers. The LSU AgCenter Botanic Gardens at Burden in Baton Rouge has been planting rows and rows of sunflowers off and on since 2012. It started with six rows of test plots of a variety named Mammoth grown by Katie Guitreau, a coordinator at the Botanic Gardens.
The gardens staff expanded the next time to two fields with black oil sunflowers from seed, and this got so much attention that they continued to expand.
In 2019, five varieties were trialed at the Botanic Gardens, and visitors voted their favorite as Henry Wilde, a multi-branching sunflower that grows up to 6 feet. They also grew Autumn Beauty, Pygmy, Mammoth and black oil sunflowers. It is free to go and see the flowers — and they are in bloom now.
A unique characteristic of sunflowers is that they track the sun, a phenomenon known as heliotropism. The flower heads turn as the sun moves across the sky. Sunflowers also symbolize optimism, positivity, long life and happiness.
Sunflowers can be easily grown from seed. You can directly sow seeds after the danger of the last frost has passed, or you can find some varieties at independent garden centers in the late spring to early summer. Sunflowers can still be transplanted this fall for more fall color.
Pollen-producing sunflowers are perfect for home gardeners who are planting to support pollinators. Photo by Jennifer Blanchard/LSU AgCenter
The National Garden Bureau has designated 2021 as the Year of the Sunflower. Photo by Jennifer Blanchard/LSU AgCenter
Sunflowers can either be single stemmed or branched, and annual or perennial. Photo by Jennifer Blanchard/LSU AgCenter
Sunflowers can be grown for seed or for producing sunflower oil. Photo by Jennifer Blanchard/LSU AgCenter
Suncredible Yellow is a 2021 Louisiana Super Plant selection. LSU AgCenter file photo