Time to Prune Salvias

Salvias are sometimes called “super shrubs,” at least in this column, because they are easy to cultivate; diverse in form, size and blossom color; and well suited for gardens in summer-dry climates, like that of the Monterey Bay area.

Many salvias have blossoms in shades of red and blue. Some uncommon varieties have white or yellow blossoms. A very uncommon species is the Beach Salvia (Salvia Africana-lutea), which has rusty orange upper petals that turn to a russet-brown color.

Salvia shrub
Salvia africana-lutea (Beach Salvia)

These form, size and blossom color qualities have supported the development of a growing collection of salvias in my garden, to the point that I have lost track of the number of plants, and of their names. I do recognize the genus salvia when I come upon it; on a good day I can name several of the cultivars. My digital files include just about all these plants in my garden, and I do intend to map their locations, one of these days, as part of the ongoing mapping project.

The recent annual Hard Pruning of the Salvias in my garden required substantial help. This necessary pruning process both supports and hinders the mapping objective.

When salvias grow closely together their branches intermingle and merge into a botanical mass that defies mapping. Gardeners who grow salvias know that they benefit from hard pruning in late winter or early spring, as new growth appears at the base of the plant. Hard pruning reduces the plants to six-to-twelve inches tall. This treatment counters ranginess and promotes bushiness, which adds to their value in the landscape. It also supports mapping by enabling the determined mapper to distinguish each plant from its neighbors.

Many salvias bloom throughout the year in our moderate climate, and many have distinctive leaf forms that can be essential clues for identifying the cultivars. These characteristics certainly help in mapping, but hard pruning hinders the process by removing all blossoms and perhaps all leaves.

The ideal time for mapping a mature salvia bed, then, occurs after pruning (while the plants are small in size) and after they begin producing leaves and blooms (which happens in early spring). Salvias’ growth cycles differ somewhat, so the plants are not all in lock-step, but this strategy should work fairly well.

Another consideration related to hard pruning salvias: after plants have been pruned seasonally, they are most visible as individual plants, ready for transplanting. As with any plant, transplanting should be done as promptly to avoid drying the roots. A good practice is to dig the hole for the plant’s new location before digging the plant. This strategy avoids any lag time between listing the plant and placing it in the new hole.

Salvias can be propagated also during the pruning season through stem cuttings.

Salvia plants also can be divided at pruning time, but this method is not recommended generally because it leaves each division with a minimal boot structure.

Finally, salvia propagation can be done from seeds collected in the early fall, i.e., around September.

One or several salvias can be botanical assets in your garden.

Pruning Salvias Hard

We want our gardens to look good, pleasing to eye, whenever possible, but occasions arise when our gardens need tough love.

Right now, in late winter, is one such occasion, particularly for salvias.

Salvias, also called sage, are excellent garden plants in a large and varied family. There are almost 1,000 species of salvias, almost all of which are native to one of three distinct regions: Central and South America, Central Asia and the Mediterranean Basin, and Eastern Asia. A few species are native to the United States.

Salvias are popular garden plants because the genus includes many forms, sizes and blossom colors to choose from, the plants are easy to grow, with few problems with pests and diseases, and drought tolerant. Many salvia blossoms are various shades of red. Here is an example the relatively uncommon Forsythia Sage (Salvia madrensis), native to Sierra Madre Oriental in Mexico, with yellow blossoms.

Salvia madrensis

Click to Enlarge

Salvias do require pruning, which is done best on an annual schedule. If your garden includes a lot of salvias, as does my garden, it is easy to skip a pruning session or two. As often happens, procrastination only postpones the task and does not eliminate the need.

When salvias are not maintained with regular pruning, they grow rangy and produce fewer blossoms. It is worth the effort regular pruning to control the size and shape of the plant, and stimulate blossoming.

There are two broad categories of salvias: perennial woody plants and deciduous soft-stem plants. Popular species in the woody group include Culinary or Purple Sage (S. officinalis), Autumn Sage (S. greggii), Germander Sage (S. chamaedryoides), Texas Sage (S. coccinea), and Baby Sage (S. microphylla). The best times to prune woody salvias, it is said, are lightly after the blooms fade (late spring or early fall, usually), and more heavily just as new growth appears at the base of the plant (late winter or early spring).

Popular plants in the category of soft-stem plants include Mexican Bush Sage (S. leucantha), Pineapple Sage (S. elegans), Brazilian Sage (S. guaranitica), Waverly Sage (S. waverly), and Gentian Sage (S. patens). These plants, which bloom on new growth, should be cut “to the ground” after the flowers have faded, or as new growth appears in the early spring.

When salvias have grown for two or three years without regular pruning, as just might have happened in my own garden, right now is time for rejuvenation pruning, also called catch-up time.

According to some advisors, pruning salvias involves careful planning and time-consuming snipping of individual stems, but when managing forty or fifty overgrown plants, the most practical tool is an electric trimmer, wielded with tough love.

We also shovel-pruned plants that had sprawled to form a large clump, moved larger plants that were encroaching into the pathway, and repositioned several low-growing, blue-flowered Germander Sages to form a border for this large collection of salvias.

Time will tell, but I expect that these plants will recover quickly from this hard pruning, , and respond with a fine new season of growth and blossoming. They are already producing new shoots.

Salvia corrugata, hard-pruned

Salvia corrugata, hard-pruned

If you are managing only a few salvias, you could prune individual stems and produce a more attractive result, but your plants are also likely to respond with a new season of growth and a profusion of flowers. Try a little tough love!

Learning More About Salvias

B. Clebsch. The New Book of Salvias: Sages for Every Garden. Timber Press, 2003.

J. Sutton. The Gardener’s Guide to Growing Salvias. Timber Press, 2004.

Basic Introduction to the Genus, on Wikipedia

Species of the Genus Salvia, from The Plant Encyclopedia

Cabrillo College’s Salvia Chart