Notes: an article from a 2004 issue of Pacific Horticulture written by Richard Turner provides an in-depth history of this cultivar:

The Truth About Salvia ‘Hot Lips’

"Our friends had invited us to spend Thanksgiving of 1999 with them and to help them celebrate the completion of renovations to their 400-year-old home, located near the central square in the colonial town of San Miguel de Allende, Mexico. Their house is made up of several small buildings separated by a series of open-air rooms, all enclosed within the high stuccoed walls that typically line the town’s cobbled streets. Where the home’s earlier residents had stored farm machinery, sheltered livestock, and hung laundry, our friends had created courtyards reminiscent of those in Moorish Spain, with stone pavement, colorful tiles, iron balconies, and splashing or dripping fountains. Pockets in the pavement provided space for the vines that drape the walls; terra cotta containers throughout offered a colorful range of flowering plants, fragrant citrus, and kitchen crops. 

Alta Gracia, their gracious housekeeper, lived during the week in an apartment on the top floor. Outside her door were pots of all types, filled with an abundance of flowers. One container caught my eye for its clever clustering of a red salvia, a white salvia, and a two-toned salvia whose red and white flowers matched perfectly the colors of the other two. To my surprise, it proved to be only one plant on which some flowers were red, some white, and some bicolored. Alta Gracia had presented it as a housewarming gift to our friends, but she was a bit cagey on its source. It may have come from a local nursery or from a nearby cemetery, where Alta Gracia admits to occasionally snipping cuttings from grave-site plants or bouquets that catch her eye, and then rooting them for her own garden (she has quite a green thumb). 

With everyone’s permission, I took cuttings of the salvia in the last few minutes before departing for the flight home to San Francisco and carefully stowed them in a zip-locked bag. Within a day of returning, the cuttings were in the hands of Don Mahoney, horticulturist at Strybing Arboretum, and the capable volunteers who propagate plants for the monthly and annual sales. The cuttings rooted quickly, and, nine months later, I was presented with the first plant from the group, lush and flowery in a two-gallon pot; it has been flowering more-or-less continuously in my garden ever since. It seems wonderfully garden tolerant, adapting to regular as well as minimal irrigation and accepting both full sun and part shade. 

Though some have suggested that pure white flowers tend to be the order in midsummer, I’m convinced that the pattern is dependent upon the age of the flowering stem, as Don first noted. The first flowers on any inflorescence appear pure red. Later buds open bicolored, with the white beginning at the base of the flower and increasing on the ensuing flowers. The last flowers on each stem are pure white. Since each inflorescence opens only a few flowers at a time, it’s rare to see monotone red and white flowers together. However, if pruned to encourage flowering stems of different ages, as was apparently done in San Miguel, a mix of red, white, and bicolored flowers will appear on a single plant at the same time. It is that pattern that makes this salvia so distinctive. 

The Strybing volunteers asked permission to name this new salvia before offering it at their sales. I had hoped to christen it Alta Gracia (meaning “high graces”), but the volunteers chose the name ‘Hot Lips’. They were soon propagating ‘Hot Lips’ by the dozens and selling them at each sale. In scarcely three years since its introduction, it now appears in public and private gardens throughout the West Coast, and is available from numerous nurseries here and, apparently, in other parts of the country. 

At the suggestion of Tony Avent, proprietor of North Carolina’s Plant Delights Nursery, Garden Design magazine named ‘Hot Lips’ one of the top one hundred plants of 2004, although it was erroneously listed as a cultivar of Salvia greggii. The consensus seems to be that it is actually Salvia microphylla, with broader, softer, and more scalloped leaves—which are also delightfully aromatic. Both species are native to Mexico, are readily available from nurseries (usually unlabeled), and are common in gardens there. 

Though the deeply spiritual Alta Gracia may not approve of the name given to the plant she found, I think she would be happy to know that so many are now enjoying the quirky beauty of Salvia microphylla ‘Hot Lips’."