Growing Polemonium (Jacob's Ladder)
Latin Name Pronunciation: poh-leh-moh' nee-um
This U.S. native perennial wildflower prospers in evenly moist, woodsy soil and along the banks of streams. Foliage appears in spring then in May and June, loose stalks of bell-shaped flowers make their appearance, generally in shades of blue. Although plants have rhizomes and form clumps of about 15-18" across, they spread by self-seeding when in the right growing conditions. More upright forms of Jacob’s Ladder look lovely in perennial borders and woodland gardens, while the spreading varieties are ideal for adding to rock gardens and alpine collections.
- Light: Prefers part shade but will tolerate full sun in cool summer climates.
- Watering: Grow in moist, humusy, well-drained soil that is rich in organic matter. Does not like to be soggy. Once well-established it is drought tolerant.
- Fertilizer, Soil & pH: Fertilize lightly once in early spring with 5-10-5 or 10-10-10.
- Pests/Diseases: No serious insect or disease problems if planted in well-drained soil and not overwatered. Deer resistant.
- Reflowering: Cut back flower stems to the base after flowering to encourage rebloom.
- Dividing/Transplanting: Space plants 12-15” apart. Grows by rhizomes but spreads by self-seeding. Can be divided in early spring as new growth appears. Long flower stems may become leggy in the spring and can be trimmed.
- Companions: Combine with Hostas, Ferns, Heucheras
Calendar of Care
- Early Spring: Cut back any remaining stems from the fall. After the plants in your garden have emerged, weed around them and apply a light 1-2” layer of compost.
- Late Spring: Once the ground warms, a light 2-3” layer of mulch will help conserve moisture in the soil and insulate roots. After flowering, cut back flower stalks to the base to encourage reblooming and to tidy leggy plants. Flowers can also be removed to prevent self-seeding.
- Summer: Be sure plants are getting enough water. If weather conditions are dry, monitor the soil for moisture and, if necessary, get out the hose or watering can. Keep in mind that plants in their first season need roughly 1” of water per week. Weed to remove unwanted plants that can crowd or take nutrients away from your plants.
- Fall & End-of-Season Care: Plants can be cut back to the ground once they finish blooming or you may choose to leave them standing until early spring.