Family: Primulaceae

The genus name is a contraction of the Latin primula veris, meaning 'the first of spring', and in times past the flowering of primulas was thought to signal the arrival of spring. This large genus includes about 400 species, mostly from the temperate regions of the northern hemisphere. Characteristic of the genus are the pretty flowers, borne in clusters on long stems above a basal rosette of leaves. The natural flower colours have been extended through extensive breeding so that flowers are now available in various shades of carmine, pink, white, red, yellow and blue. Some species have blooms with centres of a contrasting colour. Primulas are mainly perennials, but are often cultivated as annuals. They generally require a moist, cool position, and many dislike alkaline soils.

Species

P. auricula, zone 3, growing to 20 cm (8 in), has thick, often mealy leaves, to 10 cm (4 in) long. The flowers of the wild form appear in spring. They are yellow, sometimes fragrant, and are borne in clusters. The wild form, how-ever, is not generally cultivated but hybrids from it are. Auriculas have had a great following through fanciers' clubs, particularly in Europe, over the past two centuries. Formally shaped flowers, often with gold 'lacing' and patterns, are popular.

P. denticulata, zone 5, from the Himalayas, grows to about 30 cm (12 in), with 20 cm (8 in) long, somewhat mealy leaves. The flowers are borne in dense clusters in very early spring, in white through to mauve and purple, with yellow centres. A number of very decorative cultivars are available.

P. x kewensis, zone 9, a hybrid of P. floribunda and P. verticillata, appeared in one of the glasshouses in the Royal Botanic Gardens, Kew, in 1897, and first bloomed in 1899. It grows to about 45 cm 118 in) high, with 20 cm (8 in) long leaves and fragrant, bright yellow flowers, borne in clusters up the plant stem, in late winter and spring.

P. malacoides, zone 9, the commonly cultivated annual primula, from China, grows 30-45 cm (12-18 in) high. The 20 cm (8 in) long leaves are slightly hairy, pale green on top, and a little powdery on the undersides. The flowers cone in various shades of rose and lavender through to white and appear in many-flowered clusters borne either singly or in groups up the stem. This species is well suited to pots.

P. obconica, zone 9, from China, grows to 30 cm (12 in). It has hairy, scalloped leaves, about 25 cm 11(1 in) long. These can be irritating to sensitive skin. The flower clusters may be light purple, lilac, carmine or pink, sometimes with a yellow centre. The many cultivars often have flowers which are much larger than those of the wild species.

P. x polyantha, zone 6, is a complex hybrid of several species of Primula. Producing large, brightly coloured flowers, it is used as a potted plant or in massed garden displays, from winter to spring. It is mostly grown as an annual in warm climates, but is perennial in cool regions.

P. veris, cowslip, zone 5, to 30 cm (12 in), is native to much of Europe, Britain and Asia. The oval, stemless leaves, to around 20 cm (8 in) long, are hairy underneath. The deep yellow, fragrant flowers are almost flat, and are borne in dense clusters. This species is one of the parents of polyanthus.

P. vulgaris, English prim-rose, zone 6, native to much of Europe, is another parent of polyanthus. It grows to 15 cm (6 in), with wrinkled, lanceshaped, toothed leaves, to 20 cm (8 in) long. The flowers are mostly pale yellow, though occasionally purple or blue, and are borne singly. There is a very large number of herbaceous perennial primulas known commonly as candelabra primulas. These are delightful, colourful plants for cool-climate gardens and are worth seeking out from local and mail order nurseries. Most are woodland plants, revelling in moist soil and shade or filtered sunlight. Many of these species are native to China and the Himalayas.

Cultivation

Primulas do extremely well in cool to mild regions of the US. Some species do have particular growing requirements, but generally primulas will adapt to most garden soils and to sun or shade, provided there is sufficient moisture available. The tender primulas used as annual pot plants (P. x kewensis, P. malacoides and P. obconica), are grown in a cool green-house or conservatory. Raise them from seed sown in spring and pot into soilless potting compost. Grow in light and airy conditions, but shade from direct sun. Hardy primulas can be raised from seed sown as soon as ripe, or in spring, in a garden frame. Perennials can be divided in autumn or early spring.

Climate

There are species suited to various climatic zones.