Hi Ididit,
Go for full sun, at the very least 4-5 hours a day. Some of mine on the fringes of full sun are slow to produce flowers and don't have the color that they could or should.

The sun damage you refer to could have come from a very hot, blistering sunny climate. Some people use shade cloth (I think that's what it's called) or umbrellas to protect certain dahlias from the glare of midday sun. I had one last year that would just wither if I didn't put the umbrella up by noon.

Good luck.

I echo what Poochella has said. The sun is necessary. I had mine in full sun, and they did wonderful. A few years ago, I tried an experiment, and put some in partial shade. The flowering was minimal. Like me, they like the heat. In zone 7, I wouldn't think you would need to worry about full sun.

Ladies, please help! Mine did ok in the sun here in my area, however, I'm not really sure when to plant them in the ground here in Danville Va. Last year I started them up in pots,....this year I have too many to start that way. Need advice. Thanks! Margaret

Where are they now? If they're in storage you could bring them out to be exposed to light, but still need to protect from freezing. Then you can see which are going to have eyes for sure and go on to plant them.

Below is copied from MSN house and home. Warmer soil and no frost is the guide for outdoor planting. I am in zone 7 and aim for the end of April.

Poochella
**Outdoor planting can begin as soon as all threat of frost is past. Dahlias perform best in a sunny location with rich, well-drained soil. To improve a heavy clay soil, work in plenty of organic matter, such as peat and compost. Mature height dictates planting depth and spacing.

Set tubers of tall types (more than 2-1/2 feet) 3 to 4 inches deep and 20 inches apart. Shorter varieties should be planted 2 to 3 inches deep and 10 inches apart. If you buy nursery-grown plants at local greenhouses, plant them at the level they grew in their pots.**