Penstemon (P)
Perennial
Penstemon hybrid. Hardy in zones 5-9
Sow seed 8 weeks before last frost date. Sow seed on surface; provide light and average room temperatures. Seed usually germinates in 3 weeks. May also be direct seeded in spring or autumn. Plant outside after last frost date, 12 inches apart in a full sun or very light shade location. Prefers well-drained fertile soil. Use winter mulch if planted in an exposed area. Often short-lived and may have to replaced in 3-4 years. May be damaged by slugs.
Penstemon barbatus. Hardy in Zones 4-9
Penstemon digitalis. Hardy in Zones 3-8
Sow indoors, in mid-spring, onto the surface of moist soil. Cover lightly with vermiculite or soil. Propagate at 15-18°C (60-65°F). Light is required for germination. Germination should take place in 10-14 days. Maintain a soil temperature of 15°C (60°F) after germination. Use near the back of mixed perennial borders. Height is 3-4 feet (90-120cm). Flowers in late summer.
