Polemonium caeruleum Lambrook Mauve

Polemonium caeruleum 'Lambrook Mauve', also known as Jacob's Ladder and Greek Valerian, is a particularly floriferous hybrid variety with a compact and bushy habit. It blooms in summer, producing panicles adorned with bell-shaped flowers with 5 petals in a bright lavender-mauve colour, highlighted by a yellow throat. Its palmate foliage somewhat resembles that of certain delphiniums. Like other polemoniums, it is very hardy and easy to grow in fertile, well-drained, and moist soil in sunny or partially shaded locations.

Polemonium caeruleum belongs to the Polemoniaceae family. This perennial herbaceous plant is native to temperate regions of Europe and North America, and is particularly well adapted to cold climates.

The 'Lambrook Mauve' variety, belonging to the 'caeruleum' group, is a horticultural creation resulting from the crossbreeding of a Polemonium carneum and a Polemonium reptans, two plants native to North America. It is a herbaceous perennial plant forming a dense clump, reaching 40 to 45 cm (16 to 18 in) in all directions. Its foliage is deeply divided into palmate leaves, with a dark green colour that is somewhat olive-like. The Polemonium genus is distinguished by its fern-like foliage, showing dozens of small leaflets inserted perpendicularly to the central vein, like the rungs of a ladder. In 'Lambrook Mauve', in late spring or early summer, the reddish and villous stems rise above the foliage, bearing clusters of 1 to 2 cm (0.4 to 1 in) wide flowers with five petals, in the form of a deep cup. The centre of each mauve flower is golden yellow, populated by white stamens that turn yellow when covered in pollen.

Very hardy (-30 °C (-22 °F)) and easy to grow, Polemonium caeruleum 'Lambrook Mauve' will be undemanding and will form a flowery haze in the background of borders or even at the base of old roses. It thrives in any type of soil, from slightly alkaline to slightly acidic, provided it is fertile, humus-rich, moist, well-drained, and humid. Plant it in mixed borders or mass plantings in association with late tulips, Oriental poppies, peonies, pasqueflowers, or orange blooms like Potentilla fruticosa 'Hopleys Orange', with which it will create a delightful combination. This variety prefers sunny or partially shaded exposures. It pairs well with different foliage and flower colours, and adapts well to wooded gardens, rockeries, along pathways, or placed prominently as a specimen in a container, its abundant flowering attracting attention above the dense mass of its foliage.