A minty, fresh fragrance and near evergreen foliage are only two reasons to grow autumn sage (Salvia greggi). The shrubby perennial, suitable for U.S. Department of Agriculture plant hardiness zones 7 through 11, has a wealth of advantages for a busy gardener. The plant's spires of pinkish-red flowers attract hummingbirds by the score and bloom from late summer to early fall when other perennials are waning. It also needs little water once established, and deer tend to steer clear. With everything autumn sage does for your garden, the least you can do is give it a trim several times a year to keep the plant looking its best.
About Autumn Sage
Autumn sage, also called cherry sage or autumn or cherry salvia, is a Southwest native that thrives in rocky, sandy soil that drains well. Plant your autumn sage in partial shade for the best flowering -- it makes an attractive 3-foot hedge or even a foundation plant when grown in groups, and is safe to plant where children and pets play. Few insects or diseases bother autumn sage; and as long as you protect its root zone with mulch in the winter and keep it from developing woody stems, it will give you years of flowers and foliage.
Early Season Pruning
As a subshrub, a perennial that develops a woody base from which new, green shoots develop each year, autumn sage is pruned a little differently from the standard herbaceous perennial. In late winter, as new bud begin to swell, cut the plant back with bypass pruners to four or five buds from the base of the plant -- about 4 inches tall. This keeps the supple green stems that bear flowers coming and makes for a more compact plant. Cutting a subshrub all the way to the ground can remove the growing points and kill the plant.
Autumn sage can look gangly as the season progresses -- especially when planted in rich soil -- and split at the center for an unattractive look. Shearing it back by one-third to one-half encourages sturdier stems with more branches -- and as a side benefit -- more flowering stems. This can hold back blooming by a week or two. It bounces back quickly from trimming with pruning shears. Cut them straight across or in a dome shape. For a more natural look, cut each stem individually with bypass pruners back to a leaf or side stem.
Pruning your autumn sage back to the next side branch after its initial flush of bloom encourages more blooming without losing any height and keeps the plant looking neat. In USDA zones 9 through 11, cut the plant back by half again so your autumn sage stays tidy and keeps blooming through the long fall and into winter. You can pinch faded blooms off with your fingers, cut at the laterals with bypass pruners or use shears when cutting back severely.