Every summer I grow a new annual that I want to learn about. Of course, I still grow the old favorites: Nicotiana sylvestris, sweet alyssum, the dahlias that survived the winter, the rich purple Moses-in-the-Boat, and assorted salvias.
Last year I grew Shoo-fly - Nicandra physalodes - from saved seeds given by a friend. What a delicious plant!
The plant itself can grow to about five feet tall and is quite bushy; the flowers are a true pale blue and exquisite.
Shoo-fly is a relative of the tomato so the same conditions apply - warm soil, sunny, well-drained soil. Here it is growing near a seven-foot Nicotiana sylvestris that helps keep aphids off my roses. This particular flowering tobacco is candy to aphids but it has sticky leaves and they can't leave once landing. So sad.
The fresh blue flowers of Shoo-fly are welcome in the moist heat of Virginia in July. It's easy to grow from seed, flowering beautifully all summer. The seed pods are attractive and dry on the plant so you can save them for another year. Old wive's say it repels flies but the science is not clear.
You could create a seasonal hedge with this plant. It's well branched and held itself up beautifully for me. Wayne Winterrowd recommended staking it in his great book Annuals and Tender Plants for North American Gardens, a book that has been a great reference for me.
This year's annual is a tall big-petaled marigold...will see how it does and let you know.