Once it gets started in late spring, ‘Mystic Spires Blue’ salvia has potential to bloom until autumn. It only needs older floral spikes pruned away as they fade (deadheading) to stimulate new bloom. If it gets overworked and lanky without deadheading, it can be cut back in the middle of summer to start a new bloom cycle all over. It can get more than three feet tall and almost three feet broad.
Butterflies and hummingbirds really dig the small rich purplish blue flowers that are tightly packed into the upper foot or so of the floral spikes. These floral spikes tend to lean away from the center of the plant, with the tallest on top leaning collectively in one direction or another. They look like they would be good cut flowers, but they might start to drop their older flowers after only a few days.
The deep green foliage is technically evergreen, but it does not matter. All growth should be cut back to just a few inches above the ground in winter. ‘Mystic Spires Blue’ salvia likes richer soil and a bit more water than what drought tolerant salvias want. Yet, like most salvias, it grows more efficiently as #1 (1 gallon) plants planted as winter ends, than #5. Warm and sunny exposure is best.