If you think of sage only as annual summer flowers, you will be amazed. There are some species and varieties that are hardy and survive our winters well.
Sage has a lot to offer gardeners. Fortunately, among them are some attractive species and varieties that are hardy and survive winters unharmed. Overall, the genus holds not only annual summer flowers for balconies and terraces, but also aromatic kitchen herbs and many species that charm with their flower colors for years in beds.
Which sage is considered hardy?
Hardy sage includes first and foremost the varieties of the popular meadow sage (Salvia pratensis), which can withstand sub-zero temperatures down to -40 °C / -40 °F. But also the woodland sage (Salvia nemorosa) with its enchanting blue, violet, pink and white flower panicles, the natural-looking yellow glutinous sage (Salvia glutinosa) and the expressive lilac sage (Salvia verticillata) can withstand double-digit temperatures below freezing without damage. Their winter hardiness is due in part to the fact that these sage species are perennials whose shoots die back in the fall and simply resprout from the root in the spring.
The prairie or Pitcher sage (Salvia azurea ‘Grandiflora’) is somewhat sensitive and scores with light blue flowers in late summer. Its chances of surviving months of cold days and nights improve significantly if you give it a winter shelter of brushwood.
How is common sage surviving the winter?
A handsome, established garden guest is the Mediterranean common sage (Salvia officinalis). Although it originates from the Mediterranean, its aromatic varieties usually make it through the cold season just fine. This is because botanically speaking, the garden sage is a semi-shrub. As such, it does not mind if younger shoots, including leaves, fall victim to frost. As soon as the weather turns spring-like, the common sage sprouts from its old wood again without any problems. It is worth protecting variegated varieties from frost-dryness with a fleece on bitterly cold, sunny days. White variegated varieties are particularly sensitive to frost-dryness. Pruning in the late spring will help the common sage get back on its feet.
Is clary sage hardy?
As a biennial plant, the clary sage (Salvia sclarea) is a bit of a standout among all the perennials and semi-shrubs in the mint family. Unlike them, clary sage develops a basal rosette of leaves in the first year and tall inflorescences in the second year. The fragrant representative usually survives the winter without damage, but naturally dies in the second year, after it has flowered and spread its seeds.
In general, you’ll score plus points with clary sage, as with any other sage, if it is planted according to its nature in light, dry to fresh garden soils. In heavy, soggy soils, the wetness in winter usually does more damage to its roots than the cold. If you want to be on the safe side, grow young plants of clary sage in pots the first year. They do well under a canopy, in a bright garage or in the cellar. In early spring, you can transplant the offspring into the bed.
How to properly overwinter cold-sensitive sage
If you’ve ever tried to overwinter tropical species like pineapple sage (Salvia elegans) or blackcurrant sage (Salvia microphylla) in the garden bed or outside in a tub, you know it won’t work. However, you can overwinter the warmth-requiring, fruity sage species well in tubs indoors. Bright places at 5 to 15 °C / 41 to 59 °F have proven successful. However, you can also cut back the shoots and place them in the dark at temperatures between 0 and 5 °C / 32 and 41 °F. Scarlet sage (Salvia splendens) and blood sage (Salvia coccinea) also belong to the mint family. They grow perennially in their native country. In temperate climate, these popular balcony plants are cultivated only as annuals because of their sensitivity to cold.