Grow Salvia officinalis 'Purpurescens' (Purple Sage 'Purpurescens') for richly colored, aromatic foliage that works as both an ornamental and a kitchen herb. You get a compact, woody plant with purple-gray leaves that hold their color well, plus soft lavender blooms in summer that add seasonal interest.
Site it in full sun for best color and a dense, sturdy habit, though it will also perform in part shade. Give it sharply drained soil; this Mediterranean herb resents soggy, cold winter conditions. If your soil is heavy, plant on a slight mound or in a raised bed, and avoid overwatering once established.
At maturity it typically reaches about 24-32 inches tall with a tidy, bushy outline. Water regularly while it is settling in, then let the soil dry between deep waterings. In containers, make sure the pot drains freely and do not let it sit in a saucer of water for long periods.
For the best long-term shape, lightly trim after flowering and do harder rejuvenation pruning in spring, cutting back to strong stems and fresh growth. Harvest leaves as needed, and remove spent flower spikes if you prefer a cleaner look. This plant is a reliable choice for herb gardens, mixed borders, and sunny patio pots.