Even though sage is drought tolerant, new plants—whether seedlings, cuttings or plugs ordered from a nursery—must be monitored for the first few weeks. Irrigate them regularly and do not let them dry out to the point of wilting. Once the plants are well established (10 to 20 centimetres tall), watering is less critical, except during dry spells.
Whether or not to fertilize is a personal choice. In general, sages like moderately rich soil. If you’re growing culinary varieties, Richter says slightly leaner soil results in better flavour. Augment newly planted specimens, and lightly top-dress mature plants, with a few handfuls of fully decomposed compost or well-rotted manure.
Most culinary sages (save for some of the fruit-scented ones) are equally flavourful fresh or dried; leaves and flowers can be snipped as needed. Pick sage as it comes into bloom—this is when the oils (and flavour) are the most concentrated. Cut no more than a third of a plant at any given time.
If harvesting flowers only, pick them when they’re fully open and in their prime, ideally in early morning after dew has evaporated.
Perennial sage can be pruned during the growing season to encourage new foliage; cut back by about one-third as the plant starts to bloom. (Toss small cuttings on the barbecue to give poultry or pork a unique, sage-smoked flavour.) It can also be shaped in spring; trim winter-damaged branches, but don’t cut the plant back too harshly or snip into woody stems.
ut even with judicious pruning, perennial sages may become woody and unattractive after a few years. The plants can be divided, though mine always end up looking like sad, woody bonsai wannabes. Richter says propagating by stem cuttings or layering is an easy, reliable alternative.
Finally, while common sage and some of the other edible cultivars stand up well to cold, tricolour and golden sage are more temperamental and may not return after a harsh winter. Try planting those types in a protected spot, mulching lightly with several centimetres of shredded leaves, or simply take stem cuttings each fall for propagating indoors.