I have a plant that has done well for 3-4 years in a partly sunny spot. It is growing in a raised bed, so has good drainage, and gets several hours of full, hot sun, but very bright shade the rest of the time. Seems to like it. Not sure if it would take full sun, but I suspect it would.

Ah, then I suppose a good experiment would be to put a couple in full sun and a couple in part sun and see how it goes. :) Thanks!

I think this is the penstemon that grows wild in my backyard.

It only gets about four hours of direct sun, the rest of the time it's in shade.

But I'm sure it would grow in a sunnier spot with supplemental watering.

Thanks for your input!