Flower stalks that have bloomed out would be better removed unless you want them to produce seed. Many will send up new stalks. I am not familiar with the selections you mentioned. Al

Actually, the Marcus should have violet blooms, and the Snow Hill white blooms. Dead-head both, they will rebloom.

After blooming my Snow Hill gets a bit unruly looking so I cut it back. It regrows and reblooms. And yes, Snow Hill has white blooms, Snow, you know.

These are perennial salvias in Z:4.

I deadheaded mine, with in 3 weeks, they look better and bigger than they were when I picked up up from homedepot. When you deadhead it sends the plant into a hurry to re flower so it can reproduce. Just don't do it to close to frost, or let the stalks sit dry on the plant too long.

Is this the case for all perennial Salvia? Cut back the spent flower stalks after they bloom? I just planted them when they were in bloom and have no idea what to do with them now.