Hello wantonamara,
I have this plant at two very different California locations, doing well at both and I'm thinking this is a very versatile hybrid.
I have a lot of them at 450' elevation a few miles from the coast in loamy soil and here I never provide supplemental water and it does great, blooms early, like now, and have gotten fairly large, 3' x 3'
I also have a few specimens in a pinyon juniper habitat at 4000' in decomposed granitic soil. Found a huge 5 gallon specimen that had been in the pot for 2.5 years, planted it in mid summer and now after an 8" snowstorm where the 4' tall plant is located next to a juniper to protect it from the baking western exposure and the blooms that began to emerge several weeks ago are unaffected by two days of snow cover.
Seems it's a little less touchy in the garden than the straight S. dorrii species, although it's a delicacy for hares and rabbits.
I will probably provide a bit of water this coming summer only if the plants look like they will die without.
good luck.

Thank you. I can buy some bulk decomposed granite to ad to my calcareous limestone soil . Do you have tin sun in you pinyon Juniper site. That sounds hot, more like my Texas location.

I'm not sure what type of sun you are asking about but at this location there is all day full exposure, even the north side of the plants get blasted in the spring summer and fall. I try and protect my plantings from western late afternoon sun. Summer temps are usually 90-105 from July to September...maybe like Texas.

Full sun on the coast of California is a lot different from full sun inland so that is what I was asking and you answered it. It can take full BAKING sun. Many times I back off the full sun plants into places where they get half days of respit. Yes we get upper 90s- to 105 in that time frame.... mostly upper 90's till august and then all bets are off till late september. 100's still possible in october but rare. I RARELY see what is pictured above. Our cold fronts that get below freezing enough to snow are normally dry. If we have moisture it is overriding gulf or pacific air from Mexico and we get ice , freezing rain mess. Nice to know that it is cold and moisture tolerant. Today I wander around and pick a site for it.... You know I will find a site by "TROWEL AND ERROR" method of garden design..... Quote of Lauren Springer Ogden. She has another quote I like. "Darwinian Gardening". That about explains the type of gardening that I do.