Are your cuphea in containers or in the ground? I planted the similar Cuphea cyanea 'Caribbean Sunset' in very large containers earlier this year too, one in full sun, one in part sun. The one in full sun is not doing so good...lots of dried up leaves, brownish stems, no new blooms, and many of the remaining leaves have ugly blotches. All this despite careful monitoring of water requirements. The one that's in part sun is doing much better, still nice and green and some new blooms, but not as much now as in late spring/early summer. Don't know about whether it is supposed to bloom all year long.

So perhaps in hot weather areas, it's doesn't do as well in full sun. Best to give it part shade.

Just letting you know my experience!

They are in the ground. We have clay soil but the spot is slightly sloped. I've given them water but perhaps not enough in their first year with a summer that has been the hottest on record.

They'd probably be happier in a spot with morning sun only, so I'll move them this fall.

Jenn, I think they'll definitely be happier in less sun. The Strybing Arboretum for which this plant is named is in San Francisco, which doesn't t get nearly as much sun, or as intense heat, as we do in southern California. Annie's Annuals, which is based in Richmond, across the bay from SF, sells Strybing Sunset and suggests planting it in bright shade inland.

Hope this helps,
Kay

Great. I purchased them at a local native-plant sale which included some new introductions like these. The plant tag is from Native Sons, located in Arroyo Grande (where current temps are in the 70s while ours are 100+). When a tag says "Full sun" I take that to include inland areas, whereas "Full or part sun" means (to me) give it some shade inland. They must know their plants will be sold in other regions! I do research on plants after I bring them home but couldn't find much on this.

Well, I'll add "Move Cuphiea 'Strybing Sunset' to shady spot" to my list of gardening tasks for this fall.