SnapDragons - annual or perennial?

I'm in zone 7-8 and mine also fry in the heat, though a few are hanging on in a container. I love the blooms.
Gardengater

 

can they be planted in the shade to help them endure?
I had some fry and havent bothered since

 

perennials for me in Arkansas

I planted Snapdragon and giant Zinnia seeds last year, enjoyed them till late fall, then promptly forgot about them. To my surprise, they came up again this spring thicker than last year.

 

Mother, Grandmother, and I all grow snapdragons. Some of Grandmother's snapdragons come back. She has the tall variety. In the Fall she does not cut them short. In the Spring if they have new leaves, she keeps those snapdragons. She takes out any snapdragons that have no new growth.

 

Here is a snapdragon fit for a bride: Snapdragon Royal Bride is cream centered white. It would be an appropriate flower in the royal bridal bouquet.

 

Black Prince Snapdradon
http://www.pinterest.com/pin/554083560396425490