Swamp Sunflower: The Bold and the Beautiful

What should I say when somebody tells me my dog is cute?  "Thank you" is probably the right response, but why?  I had absolutely nothing to do with my dog's cuteness. 

I feel the same way about swamp sunflower, which right now is getting all the attention in my garden.   It is, bar none, the most spectacular plant in town right now.  But I take no credit for it whatsoever.

For those of us in the Southeast, swamp sunflower (zones 6-9) may just be the perfect plant.   It's beautiful, it's low maintenance, and it's pretty much disease-free.  Plant it in full sun, give it decent soil, and make sure it gets some water during dry spells, and you'll look like a pro.  Put it in a soggy spot, and you'll look like a genius. 

There are several perennial sunflowers out there, all going by the Latin name Helianthus something-or-other  and differing mainly in height, bloom time, and soil preference.  The plant that is currently signaling ships in my garden is a late-blooming variety native to the Southeast.  Since my original clump was a freebie from my neighbor's garden, it took a bit of detective work to figure out exactly what variety it was.  Finally, I determined that it is identical to the one Niche Gardens sells as Helianthus simulans - useful information if you actually plan to purchase it, rather than ogle it in your neighbor's yard and hope he'll get the hint.  

Perhaps swamp sunflower would be less eye-catching if it flowered in the summer, when there is a lot more competition in the bloom department.  But here in Cary, it starts flowering in early October and continues through a good portion of the month.  Yes, chrysanthemums and asters are everywhere, and plenty of summer-blooming plants are getting their last words in.  But nothing else is screaming yellow and seven feet tall. 

Clearly, this is not a plant for the shy and retiring.  And if seven feet seems gargantuan, consider this: I generally cut mine back by 1/3 in late June to keep the height under control.  Yes, seven feet tall is "under control" - they can reach ten feet if you  do nothing.  Like chrysanthemums and asters, swamp sunflowers should be cut back by July 4th (a date gardeners use because it's easy to remember); any later, and they won't have time to form buds and bloom before the first frost.  

If this plant has any drawback, it is that those seven-foot stalks never stay up in the wind or the rain.  Generally I like the sprawling, natural look, but even I find swamp sunflower quite disheartening in a horizontal state - after all, its dramatic height is the whole point.  I've learned my lesson and now I stake it, using a galloping horse version of the cat's cradle that involves five foot tall tomato stakes and green garden twine.   It's not pretty, but it works, and it's virtually invisible when the flowering begins.

And what flowering it is.  Amazingly, swamp sunflower looks great with almost everything in bloom right now - Mexican bush sage, asters, ornamental grasses, you name it.  You can plunk it practically anywhere and voilà - a great plant combo is born.  For Southeastern gardeners, it just doesn't get much better than this.