Ask Mr. Smarty Plants

Indigo Spires is not considered a native plant, but we have had several questions about it in the last year or so. We are going to extract some of the information from some of those answers and see if it will help. 

"Indigo Spires, sometimes called Mystic Spires, is thought to be a hybrid between Salvia farinaceae and S. longispicata. It was found growing at the Huntingdon Botanical Gardens in California in the 1970s. The botanist who discovered and named it noticed that it the new plant was growing near the other two, and theorized that it was an accidental hybrid. Salvia farinacea (mealycup sage) is a Central Texas native, but the S. longispicata is something of a mystery, thought to be native to Mexico. In fact, when we went googling to try to find information about it, it was always in combination with S. farinacea to make Indigo Spires. When you're unclear about the parentage of a plant, it is very difficult to diagnose problems or recommend care. So, we found some facts, including in our Native Plant Database, about S. farinacea, and hope they will apply to the mix of two salvias. We learned that salvias hate to have wet winter feet, but also hates having roots dry out and will quickly die when that happens. If your salvia was in a poorly drained bed, it might be suffering from drowned roots. It's more likely, however,  that the salvias are suffering from being dried out. You are going to need to trim out the upper part of the plant anyway, to take some of the strain off the roots, and then make sure it has moist soil around the roots. Under ordinary circumstances, it is advised to cut back old flower stems when new basal foliage begins to appear. Don't fertilize until the plant is recovered, if it recovers, and we hope it does. Just as an aside, hybrids like this are sterile, or their seeds will not breed true to the original plant. If you wish to propagate it, take stem cuttings." 

Pictures of "Mystic Spires" Salvia