Sage

Divide or start replacements every few years

Split large plants in spring, or root softwood cuttings in summer in a moist, well-drained mix to grow on as replacements. Rooting hormone is generally not necessary. Plan on replacing culinary plants every few years rather than trying to rejuvenate an old woody one. Garden sage tends to be a short-lived perennial that goes woody and unproductive with age, so keeping a younger plant coming along is what keeps you in usable leaf.

Cut back in spring, but stop at the old wood

In mid- to late spring, once stronger new growth appears, prune back to a low framework of branches, cutting just above a healthy pair of shoots. Keep it light rather than hard, clear out dead twiggy stems, and never cut down into bare mature wood. Sage is a subshrub that builds woody stems with age, and older stems may not reshoot, so a cut back into bare wood is risky and can leave a permanent dead stub instead of regrowth.

Keep it cut back so it does not run to flower

Through the growing season, tip back the shoots a few times to keep the plant bushy and to head off flower spikes. If you are growing sage as an ornamental instead, let it bloom and cut it back once the flowers fade. Flowering shifts the plant's energy out of leaf and into seed, and the leaves on a blooming, leggy plant are the weaker-flavored ones; young shoots hold the best flavor.

Watch for the wet-soil diseases, and fix the drainage instead

Check plants for powdery mildew, spittlebugs, spider mites, slugs, and leafhoppers, and for stems that wilt or collapse from root rot. Space plants 18 to 24 inches apart for airflow and move sage to a well-drained site rather than reaching for a spray. Sage has few pests when the soil drains freely; nearly all of its real trouble is root rot and foliar fungus driven by wet soil and stagnant air, and no spray fixes a drainage problem.

Winter survival is about drainage, not cold

Going into winter, make sure sage is not sitting anywhere water collects. Do not pile wet mulch over the crown. If your plant is a colored-leaf cultivar in a cold zone, take summer cuttings and overwinter a rooted plant indoors as insurance. Sage must have very well drained soil especially over winter to come through as a perennial; the ornamental purple, golden, and tricolor cultivars are also less hardy than the plain species and are the ones that fail in a cold zone.

Cut the top 6 to 8 inches, twice a season

Pick leaves as you need them, and at least twice over the season cut 6 to 8 inches off the tops of the plants for drying. Never take more than half the plant at once. Cutting back the tips keeps pushing young shoots, which carry the strongest flavor, and stripping more than half at once leaves too little leaf area for the plant to rebuild and it stops producing.