If you travel the country roads in many eastern states right now, you'll see the native version of helianthus angustifolius, also known as swamp sunflower. The native version can grow quite tall, sometimes reaching about eight feet. In my perennial gardens, I grow helianthus angustifolius 'First Light' PP#13150 which is a more compact 4'x4' size. Swamp sunflower grows in zones 5-9. If you plant this favorite, you'll be rewarded with generous blooms in September until frost in zone 7. You can leave the seed heads for the birds in winter or cut back if you want a neater garden. Divide with a shovel to create more plants.
This swamp sunflower was one of the first perennials that I planted when we built our home in 2005. It is planted on the east side of the house beside an outdoor water faucet. White butterfly ginger is the companion for this sunflower and both are in bloom right now. The sunflower is literally a mass of yellow daisy-shaped flowers. I divided it for the first time last spring and added a clump to my rain garden where salvia uliginosa (bog sage) keeps it company. I purchased another pot and planted that one in a hotter location that has rich, moist soil.
Helianthus angustifolius is supposed to be deer resistant. The most exposed clump has been nicely pruned and shaped to just under 3 feet in height by the local deer herd. They did such a nice job pinching back the blooms and shaping the plant, that this clump looks better than the lanky clumps that were untouched. It has more blooms, too. Next year, I think I'll follow their example and pinch back the stems on the other clumps of swamp sunflower!
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