News Release Distributed 08/10/12
By Allen Owings, LSU AgCenter horticulturist
Sunflowers are among the easiest flowers to grow, and they thrive in the heat of our summers. It may be towards the end of summer, but you can still plant sunflowers and enjoy them during fall. In north Louisiana, try to complete sunflower planting by the third week in August. In central Louisiana, complete planting by the end of the month, and south Louisiana gardeners can plant sunflowers through Labor Day.
Depending on the variety, sunflowers will bloom anytime from about 55 to 75 days after planting the seeds. About 60 days is a good average. Sunflowers can be broadly divided into those that are grown for seeds and those grown as ornamentals and cut flowers. Most people are interested in the ornamental and cut-flower types.
You can start sunflower seeds in small containers that have drainage holes and are filled with potting soil. Place the containers in full sun to produce strong, stocky transplants. Make sure you water regularly, and never allow the soil to become dry. When the seedlings have grown to be 4 to 6 inches high, transplant them to sunny flower beds.
It is faster, however, to sow seeds directly into a prepared garden bed in full sun. It is common to plant sunflowers into landscape beds, and many gardeners include a row of sunflowers in spring and fall vegetable gardens. After sowing the seeds, water the bed well and then water again as needed to keep the soil moist – every day if the weather is dry.
Sunflowers come in heights ranging from 1-8 feet and come in a wide range of flower colors. While brilliant yellow will always be popular, you can also choose from creamy white, bronze, mahogany, rusty red, burgundy and orange, with some types producing flowers with more than one color. The center disk of the sunflower also adds to the display and goes through color changes as the flower matures and seeds form. Double types produce flowers full of petals with no central disk at all, such as Teddy Bear. Ornamental varieties for cut flowers include Sunbeam and Sunbright.
Sunflowers that are grown for cut flowers generally produce numerous flowers on a bushier plant than those grown for seeds, which generally produce a single large head. The multiple-flowering habit makes cut-flower types more colorful and helps them fit into traditional flower beds more appropriately.
If you want to grow sunflowers for the delicious, nutritious seeds, make sure you choose varieties bred for seed production, such as Mammoth Russian, also known as Mammoth, Russian Giant and Gray Stripe. These tall-growing sunflowers produce a single, enormous flower at the top of the plant. To grow a really big seed head, apply general-purpose fertilizer when the flower head begins to appear.
The versatility and variety of today’s sunflowers offer something for almost every garden and gardener. If you haven’t tried this native American plant lately, give it another look.
You can see more about work being done in landscape horticulture by viewing the LSU AgCenter’s Hammond Research Station website. Also, like us on Facebook. You can find an abundance of landscape information for both home gardeners and industry professionals.