By Joyce Comingore
"Sister Susie Sells Seashells by the Seashore and Spreads Sunflowers on Sand Dunes."
Do you have an area where you need a fast growing ground cover or a hillside that is eroding away? The answer to that is the beach sunflower, Helianthus debilis. The beach sunflower is also perfect for the space between your sidewalk and the street, or along the edge of your driveway, or any difficult to water area. It will fill in and spread fast by above ground runners and later by seed.
The roadway, driveway, sidewalks and sea walls are important places that can help you live green, because beach sunflowers need no water or fertilizer once they are established. Ergo, no fertilizer or pesticides to run-off down into your drainage areas, or off into the canals, waterways and wetlands. It saves mowing, because all you need to do is pull the weeds out that manage to grow under all that vegetation, which are few and far between.
Keep an eye on its spreading if you don't want to find it growing in your shrubs. Runners are easily pulled out if they get out of hand, and they take well to being cut back in the spring and summer. Removal of spent plants is advised after about two years. It helps to clean up and thin the mass out.
The tall sunflower, Helianthus annus, is an annual that belongs to the aster/daisy family of which there are 38 perennial varieties native to North America. The beach sunflower genus is one of the native perennials in South Florida, especially in the sandy coastal areas where it stars as a colorful, abundantly flowering, sprawling ground cover year around. Being suitable for dry, sandy, coastal places, year long color, free from pests and ease of growing, makes it an ideal xeriscape plant. The drawbacks are, if it is in poor drainage with an over abundance of water, and also, fertilizer, then they decline and die.
Helianthus debilis is an annual above zone 8, because it freezes. Here, in zones 8 through10, it is a short-lived perennial because it gets leggy and woody with age over a few years, needing periodic removal of spent plants that will then fill in, in no time, because it is a fast grower. Being salt tolerant, it becomes useful on banks and slopes in beachfront situations. Long used for dune stabilization, it also helps inland with hillside erosions, hard to water areas and adds a bright colorful ground cover. It does well in direct sunlight.
With dark green, triangular, sandpapery coarse, hairy leaves and 2-inch miniature yellow sunflowers having brown/purple centers that bloom all year long, it can grow erect to 3 or 4 feet, or be a multi-branched, prostrate spreading plant, depending on the variety. Their small black sticky seeds are kernels with an oily seed wall that will germinate on top of mulch.
I noticed in my information about the best time to plant beach sunflowers, every month except January, was mentioned for zones 10 and 11. Native Americans used these flowers and seeds to get the purple/black and green colors for their body painting, dyeing textiles, pottery and baskets. The flowers are favorites of butterflies and the seeds attract birds. We have used the cut flowers in floral arrangements .
There seem to be two subspecies of beach sunflowers occurring naturally on beaches and sand dunes along the coastal areas of Florida's peninsula all the way over to southeast Texas. Helianthus debolis subspecies debilis is prostrate, reaching a height of maybe 18 inches, and occurs along both coasts of Florida. It has been introduced northward to North Carolina along the Atlantic coast. H. debilis subspecies cucumerifolius (cucumberleaf sunflower) is erect and occurs along the northern gulf coast of Florida west to Texas, and inland. There is an "Italian white" variety that grows up to 5 feet tall with 4-inch flowers of pale yellow or creamy white petals and a black center. "Flora Sun" beach sunflower (Helianthus debilis Nutt. "Flora Sun") has been released by the U. S. Department of Agriculture. It grows well in all of Florida on over the gulf coast to Texas, but they do not recommend it for use on the west coast from Pinellas to Sarasota counties, in order to avoid a possible genetic cross with the beach sunflower grown there.
Warning - there is a non-native lantana camara that is genetically swamping the true native lantana depressa. It is suggested that you use beach sunflower instead of lantana camara as a flowering ground cover. The Florida Exotic Pest Plant Council classifies L. camara as a Category l exotic pest "known to invade and disrupt native plant communities."
Also, its leaves and fruit are very toxic to animals and humans. So be very careful when buying non-native lantana-they are often sold as natives in large commercial nurseries.
I bought my sole beach sunflower plant at a native plant sale. I planted it on the east side of my butterfly bed. In two years, that one plant had expanded to an 8-foot-square area. Beautifully filling in all the bedding area, I didn't need to weed much.
Plant beach sunflowers to bring sunshine to your yard and watch the butterflies visit to pay their respects.
Thank a plant for your fresh air.
Joyce Comingore is a master gardener, on the National Board Director of the American Hibiscus Society and a member of the Garden Club of Cape Coral.