Salvia farinaceae x longispicata "Indigo Spires"
This wildly popular hybrid is a cross of Salvia farinaceae (Mealy Cup Sage) and Salvia longispicata, discovered as a seedling in the 1970's. There are good reasons for its popularity: it blooms nonstop until frost; it's ever so showy, with dark violet flowers on twisted spikes; it's a fast grower; hummingbirds and butterflies totally approve; and if given enough sun (at least five hours a day) and well-drained soil, it will be the showpiece of your garden for a long time. Clump-growing Salvia "Indigo Spires" grows from three to six feet tall, with a spread of one to three feet. Most sources say this Salvia is hardy in Zones 7-10, but some suggest winter protection in Zone 7. If you're on the cusp, I recommend taking cuttings (Salvias are a breeze to propagate from cuttings) or planting it in a large container and moving it inside for the winter. Quarts. (Photo from Wiki Commons and in the public domain.)