Grow Reblooming Sunflowers for Bees, Birds and Bouquets

The happy faces of sunflowers are a necessary presence in a summer garden, and I’ve never met a sunflower I didn’t like. But for the past few seasons I’ve been trying off-the-beaten-track reblooming sunflowers, and I think I’m in love.

Annual silverleaf sunflowers (Helianthus argophyllus) and beach sunflowers (H. debilis) are as easy to grow as common sunflowers, but they branch like crazy and bloom for months rather than weeks, often through the first frosts. Bees and butterflies love the saucer-size flowers, held on stems just long enough for cutting. As soon as the oily seeds are ripe, goldfinches, chickadees and other nimble birds arrive to eat them.

Spectacular Silverleaf Sunflowers

Native to the Gulf Coast of the US, silverleaf sunflowers have softly felted leaves covered with tiny hairs, which deter feeding by insects and animals and insulate the leaves from drought. The silvery foliage is stunning when combined with the bright flowers with chocolate centers, which are eagerly visited by butterflies and bees. As with pollen from common sunflowers, silverleaf sunflower pollen has been found to promote better health in bumblebees and honeybees by helping to control a common pathogen.

The tallest silverleaf sunflower branches can grow to 12 feet (4m) or more by the end of the season, but they seldom stand upright. Having evolved in a hurricane-prone climate, silverleaf sunflowers cope with stormy weather by toppling over. Upright blooming stems then grow from the tilted main branches. It’s therefore good to give them something to lean on, be it a fence or a cage. Don’t worry if a few brittle branches break off. The plants seem to enjoy being pruned by whipping winds.

Bird-Pleasing Beach Sunflowers

Variously known as beach sunflowers, dune sunflowers, or cucumberleaf sunflowers, Helianthus debilis originated along the southeastern coasts of the US. The bushy plants tolerate humid heat and salt spray, requiring little or no maintenance. The cucumberleaf subspecies has ragged-edged leaves, and it is famous for its three-month-long bloom time.

In addition to the straight species, which bears bright golden blossoms, varieties have been selected that provide new twists in flower color and growth habit. For example, perhaps 200 years ago, Italian immigrants to the US began growing an almost white strain, which they took back to Italy, and then brought back to North America as Italian White. You can still buy seeds under this name, but I suggest upgrading to more vigorous Vanilla Ice, which can grow to about 5 feet (1.5 m) tall and produces creamy blossoms nonstop from midsummer to fall.

Want more color? For years it has been known that beach sunflowers carried genes for bronze and gold colors, but it was not until fairly recently that Dutch plant breeders crossed and selected for flower color and growth habit to develop the Soluna series for use as cut flowers and garden plants. From lemon yellow to rusty bronze, Soluna sunflowers are just the right size for bouquets, and the bushy plants top out at about 4 feet (1.2m) tall. If you start with a seed mixture, you can save seeds from your favorite shades.

Growing Reblooming Sunflowers

Like tomatoes, these and other annual sunflowers are warm-season plants that cannot tolerate frost. Start the seeds indoors in mid spring, about three weeks before your last frost date. Set them out in late spring to early summer, but don’t hurry. The seedlings can be held in pots until the soil loses its winter chill, and they grow quite well in roomy containers.

After the plants have been set out and show steady growth, it’s a good idea to pinch the first buds soon after they open. This encourages the plants to develop a strong branching pattern, which will serve it well in the months ahead.

Silverleaf sunflowers can cross with common sunflowers, so be careful when saving seeds. Waiting until late in the season is a safe strategy, because reblooming sunflowers keep going well into the autumn, long after other sunflowers are gone. After the petals fall, tie small paper bags over prime blossoms to protect the ripening seeds from birds. Wait until the stems turn brown to bring the seeds indoors to finish drying in paper bags.

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