Bitterweed stands up to drought

I've always been a pushover for daisies. So when I discovered a patch of bitterweed (Helenium amarum) growing near U.S. Highway 17 and Oak Forest Drive and Farmfield Avenue in West Ashley about a month ago, I had to take a closer look.

Although a rectangle of hard-packed soil just inches from a busy thoroughfare hardly could be defined as an ideal gardening spot, these little guys, with their nickel-size neon-yellow blossoms, were cheerfully nodding their heads to everything that whizzed past them. Even though they were severely stunted (bitterweed is usually 12-14 inches high and twice as wide), they had managed to survive the indignities of heat, exhaust fumes and mowing.

When I first spotted this clump of vegetation, I must admit that I had no idea what it was. After all, there must be at least a zillion different kinds of daisylike yellow flowers that grow in the Southeast. Yet when I returned to the site on the following day for a more studied observation, I began to recall an incident from my botanical past. I had seen a variation of this plant before.

Familiar face

Decades before moving to Charleston, I had spent an idyllic weekend near the Delaware Water Gap. Sitting in a meadow on top of the Pocono high plateau with Roger Tory Peterson's "Field Guide to Flowers" in hand, I learned how to identify sneezeweed (H. autumnale). And just like those daisylike flowers in that abandoned Pennsylvania pasture, the ones growing along Highway 17 had 3-lobed petal tips.

Although this is an excellent identification marker for Heleniums, I still wasn't confident that I was on the right track. The plants in Charleston had threadlike, filiform-shaped leaves instead of the lance-shaped ones I had seen up North.

It was time to consult Richard Porcher's "Guide to the Wildflowers of South Carolina." And there it was, my mystery plant, with skinny leaves and eight bright yellow radiating petals smiling up at me from Page 386. Bingo!

Since making this discovery, I probably know more about bitterweed than most gardeners ever care to hear about. But I bet I can pique some genuine interest after folks learn that these plants are nearly indestructible.

Tough stuff

Bitterweed is a native, low-maintenance annual that laughs at heat and humidity. And because of its peculiar leaves, thick main stem and strong taproot, bitterweed is extremely drought-resistant. Give this plant full to partial sun and it will bloom from spring through early winter or whenever 32-degree temperatures finally knock it out.

The only caveat to growing bitterweed is that it's poisonous to livestock and humans. But since I've never encountered cows, goats or sheep around town (not yet, anyway), and I assume that our good citizens have enough sense not to nibble on the local flora, I can cultivate this rugged Helenium with a clear conscience.

Although bitterweed grows wild throughout South Carolina, a garden variety named 'Dakota Gold' is commercially available. But because bitterweed's home landscape value is underappreciated, its plants and seeds might be difficult to find. However, one seed source, Summer Hill Seeds (http://summerhillseeds.com) in Whittington, Ill., has assured me that it has plenty of fresh 'Dakota Gold' seed for the 2008 season. Simply follow the sowing and growing instructions on the seed packet.

For gardeners who would rather start with youngsters instead of tending baby seedlings, Ball Horticultural Co. (www.ballseed.com) includes 'Dakota Gold' plants in its "Simply Beautiful" collection (www.simplybeautifulgardens.com). However, this series is available only through retail garden centers, including a couple in the Lowcountry.

If you have a challenging spot in your garden that drives you nuts every summer and you don't mind adding another yellow daisylike flower to your horticultural repertoire, then bitterweed might offer a solution.

P.J. Gartin has been a Charleston County Clemson Extension Service Master Gardener since 1990. She is the author of the book "Some Like It Hot: Flowers That Thrive in Hot Humid Weather" (Gibbs Smith, 2007). E-mail her at askamg@hotmail.com.