Description and general information:
Polemonium pulcherrimum or showy Jacob's-ladder, is a tufted plant, to 30 cm, with erect to decumbent stems. Leaves are pinnately divided into 9–21 widely oval to round leaflets. The plant has a skunky smell when bruised. Flowers are produced in terminal clusters. Individual flowers, about 2.5 cm across, are saucer-shaped and have five blue petals fused at their base. The center of the flower is yellow.
Plants are found in the subalpine and alpine zones (about 8,000-11,000 feet) of the western US, Alberta, BC, Yukon and Alaska, growing on gravelly soils and talus slopes.
Cultivation:
This species requires full sun in northern areas but light shade in hotter regions. If exposed to drought, plants may go summer dormant or possibly die. Moist but well-drained soil is ideal. If kept reasonably moist, plants will bloom throughout the growing season. Alkaline or neutral soil is best.
Bloom period:
In the wild, this species blooms late May through late July. In milder climate, flowering commences in late March while in more northern regions, May-June is the normal flowering season.
Propagation:
Seed, division, cuttings
Seed:
Seeds require light for germination so surface-sowing is required. Ontario Rock Garden and Hardy Plant Society suggests seeds may be directly sown at 20 C and germination will occur within 3 months. Stratification is not required.
Division:
Larger plants could potentially be dug and divided in early spring or late summer.
Cuttings:
A piece of rhizome with a tuft of leaves, may be used as cutting material.