Pruning Russian sage

Russian sage flowers on new growth produced in spring, so annual hard pruning is essential to keep plants compact, floriferous, and tidy. Left unpruned, the woody base becomes increasingly gnarled and the plant sprawls outward with sparse flowering at the tips. Prune in March or April, just as the new green shoots begin to emerge low down on the old stems. Pruning earlier in winter can expose tender new growth to frost damage; waiting until late spring delays flowering. Use sharp secateurs or loppers and cut all the previous year's growth back hard to within 10–15 cm of the ground, just above the lowest visible buds or new shoots. Don't worry about cutting into old wood—Russian sage responds well to this treatment and will quickly produce vigorous new stems. If your plant has become very woody and overgrown, you can rejuvenate it by cutting even harder, down to 5 cm, though flowering may be slightly delayed that year. Remove all the pruned stems and foliage; they can go on the compost heap or be disposed of. After pruning, the plant will look like a collection of stubby brown sticks, but fresh silvery-grey foliage will soon appear. If you garden in a very mild area and want to tidy up in autumn, you can remove the spent flower spikes after flowering finishes, but leave the main framework of stems intact until spring. This provides some winter structure and protects the crown from excessive wet. Avoid autumn hard pruning, as it stimulates soft growth that won't survive winter frosts.