I have some in my window boxes this year. They are doing great so far. My experience in the past with them though is they do better with about half and half exposure with sun/shade. The heat doesn't seem to bother them but too much direct sunlight will burn them. Also, do not let them dry out at all. Once they dry out, they seem to go beyond the point of return. However, if it is early enough in the season, you can shear them back and they will come back pretty well. I have white and blue this year and they look fantastic. Good Luck.

I grow them in hanging baskets with only early morning sun. They are watered with drip irrigation every other day. When they go to seed the seed drops to the ground and grows next spring. One of my wife's favorites. Al

I buy the 'Moon' series. I've had the best luck with them. Mine are planted where they get about 4 hrs of early morning sun. I also mulch them so they don't dry out. They don't like the afternoon sun when it gets hot. Mine last the whole summer as long as I don't let them dry out. Btw, the leaves on mine have a green/burgundy color too, which I like. I don't think all the 'Moon' series ones have that color, but the ones I get do.
Good luck with yours!

Kat

This is my first year to grow them. I planted some in pots on my porch in very early spring expecting them to burn up when our heat moved in. Surprise! They are still going strong and we're a month into high eighties and low to mid nineties. I suspect the answer is morning sun, afternoon shade.