Polemonium 'Blue Pearl', commonly known as Jacob's Ladder, is a beautiful hardy perennial producing masses of soft lavender-blue flowers with golden stamens above elegant fern-like foliage. Blooming in late spring and early summer, it thrives in moist, well-drained soil and is perfect for cottage gardens, woodland borders and pollinator-friendly planting.
Loved by bees and other beneficial insects, the flowers also make charming additions to cut flower arrangements. Easy to grow and returning year after year, Blue Pearl brings graceful colour and delicate texture to the garden.
When to Sow: September–October outdoors for natural stratification, or February–April under cover.
HOW TO SOW POLEMONIUM: NEEDS COLD STRATIFICATION. Autumn sowing is ideal, allowing natural winter chilling, or refrigerate seed for 4–6 weeks before spring sowing.
Sow onto the surface of moist seed compost and lightly press the seed into the compost, covering only with a very light dusting of vermiculite. Germinate at 15–18°C and keep the compost evenly moist.
Classification: Hardy perennial.
Expert Level: Required Some Experience
Germination Time: 3-4 weeks after Stratification
Site: Full sun or partial shade.
Soil Type: Fertile, humus-rich, moist but well-drained soil.
Soil Acidity: Acid, neutral or alkaline.
Moisture: Moist but well-drained. Avoid prolonged drought.
Care: Water well during dry spells, especially while plants establish. Deadhead spent flowers to encourage a second flush, then cut stems back to ground level in autumn. Divide mature clumps every 3–4 years.
Use: Excellent for cottage gardens, woodland planting and pollinator borders. The delicate sprays of flowers also make charming additions to informal, garden-style bouquets.
Harvesting: Cut stems when around one-third to one-half of the flowers on each stem are open. Place immediately into water for the best vase life.
Days to Maturity: 90–120 days from an early spring sowing under ideal conditions; autumn-sown plants flower the following spring.
Vase Life: 5–7 days.
Height: 60–90 cm.
Plant Spacing: 30–40 cm.
Flowering Months: May–July
Polemonium (Jacobs Ladder) Blue Pearl
Approx. 142 Seeds per pack. Please note that the majority of our seeds are packed by volume so the number of seeds indicated is an approximation.
We make every effort to provide British seeds where possible, but in some cases our British Growers are unable to grow in sufficient quantities to meet our demand or the seeds are subject to Plant breeders' rights which means it is only possible for us to buy these seeds from certain non UK flower farms