Capitatae Section from the Himalayas. Biennial here, perennial where snow covers all winter and on the West Coast. Flowers late (July). Flat rosettes of delicately toothed leaves, twelve-inch silver stems; flat silvery heads of slightly drooping flowers. Disappears over winter.
Cortusoides Section from Asia. Woodsy-rich humusy soil. Decorative leaves usually soft hairy. Flowers in spring. Disappears over winter.
Denticulata Section. Small group from the Himalayas. Easy perennial. Be careful about dampness in winter. Among the earliest to flower in spring.
Farinosae Section. Huge group from many lands. Moisture, drainage, part shade. Stand more sun if moist. Small bud, usually white at surface, shows in winter.
Nivalis Section from Asia. Biennial here. Long narrow leaves. Flowers in tiers closer than candelabra and more drooping. Cool, rich, moist soil, part shade. Flowers in early spring; disappears in winter.
Sikkimensis Section from Asia. Belled primulas, with hanging heads of bell-shaped flowers. Biennial here; perennial in both colder and warmer climates. Most tall with heads of fragrant flowers held well above large toothed leaves. Flowers in late spring; disappears in winter.
Vernales Section includes all the easiest-to-grow and best-known primulas. Requires part shade, rich soil, moisture; should never be completely dry. Evergreen. Includes: P. vulgaris (acaulis), single flower per stem; P. polyantha with many varieties, and stalked umbrella of flowers above the leaves; P. juliae hybrids. Among P. polyantha there are some dwarf hybrids (not miniature).
CARE. Some shade for hottest part of the day. Woodsy soil rich in humus, neutral or slightly acid. Mulch with manure if possible, around and between plants; don’t cover crown. Keep moist. Provide winter protection of salt hay, evergreen boughs, or excelsior, which results in gradual thawing of the ground around the plants in spring, and also prevents premature blooming during unseasonably warm winter days. Fertilize in spring, and in summer for next year’s flowers. No nitrogen in summer fertilizer. Watch plants for signs of slugs and red spider. Divide when plants get too crowded, preferably after flowering. Hearty seeders.
PROPAGATION. Seeds when ripe (others must be frozen first and thawed), division after flowering.
SPECIAL USES. Carpet under shrubs and under early-flowering trees. Naturalize by streams and beside pools. Wall planting, rock gardens, borders, wild gardens.