Family: Boraginaceae
Common Name: Blue Bells

This genus comprises some 50 species of perennials from temperate countries of the northern hemisphere. These plants may be prostrate or clumping, with some species forming neat mounds. The simple, smooth-edged leaves are blue-green in colour and the blue, bell-shaped flowers form drooping clusters.

Species

M. ciliata, zone 4, originally from the west of the United States, is a woodland species, growing to 60 cm (24 in) high, with rose-coloured buds, followed by clusters of bright blue flowers on upright stems.

M. primuloides, zone 5, a native of the Himalayas, is a dwarf, growing to only 15 cm (6 in) high and producing deep indigo blue flowers. Varieties with white and yellow flowers are available.

M. pulmonarioides, Virginia cowslip or blue bell, zone 3, native to eastern United States, is probably the most popular species. It grows to about 45 cm (18 in) high and has intense blue flowers in mid and late spring.

Cultivation

Mertensias combine well with azaleas, ericas and rhododendrons, and make a colourful addition to semi-shaded areas of rock gardens. They grow well in the open but must have a lime-free soil and plenty of water in spring. The flowers last longer if these plants are grown in cool, shady spots. Propagate from seed or by division of the roots in autumn.

Climate

There are species suited to various climatic zones, but all are very hardy.