Height 7.5-12cm (3-5in)
Planting distance 7.5-10cm (3-4in)
Flowers late winter to early spring; also autumn
Full sun or dappled shade
Corms available in mid summer for autumn flowering, and autumn for spring flowering
Crocuses come from the mountainous regions of southern and eastern Europe, so they are remarkably hardy. In gardens they provide some of the earliest spring colour at ground level, though there are several species that are autumn-flowering. Most species stand about 7.5cm (3in) high – the Dutch hybrids are slightly taller at 10-12cm (4-5in). The flower colours vary enormously, coming in shades of yellow, blue, purple, lilac and white according to the species and variety. Some are only one colour, some are bicoloured, others are striped. All have thin green leaves with a faint white stripe. The leaves of spring-flowering crocuses appear with the.
Crocuses are happy in sun or dappled shade. They are best grown in clumps in rockeries or sink gardens, but they also look attractive edging flower or shrub borders. The more robust species are ideal for naturalizing in short grass, provided it is not mown before the leaves turn yellow in late spring. Try planting autumn-flowering crocuses among low ground cover.
Popular species and varieties
Crocus ancyrensis, often listed as ‘Golden Bunch’, has 5cm (2-1/2in) high rich yellow flowers in late winter and early spring.
Crocus chrysanthus has 7.5cm (3in) high golden yellow flowers in late winter. It is suitable for rockeries, borders and containers. Popular varieties are ‘Advance’ (yellow and violet), ‘Blue Bird’ (violet and white), ‘Blue Pearl’ (blue and white), ‘Cream Beauty’ (cream), ‘EA Bowles’ (yellow with bronze base), ‘Elegance’ (bright golden-yellow, brown markings), ‘Fuscotinctus’ (striped and feathered plum-purple on pale yellow ground), ‘Lady killer’ (purple and lilac-white), ‘Princess Beatrix’ (clear blue with yellow base), ‘Prins Claus’ (deep violet-blue flushed with white), ‘Snow Bunting’ (white), and ‘Zwanenburg Bronze’ (garnet-brown and yellow).
Crocus imperati has 7.5-10cm (3-4in) high flowers with buff outer petals streaked purple, and bright purple satiny inner petals. It is another early-flowering species appearing in mid to late winter.
Crocus medius has 7.5cm (3in) high, lightly scented lilac blooms with deep orange stigmas. It is one of the autumn-flowering species. Grow in a sunny spot.
Crocus sieberi has 7.5cm (3in) high pale mauve flowers with yellow bases. These appear in late winter and early spring. Two garden hybrids have been developed: ‘Hubert Edelsten’ (rose-lilac) and ‘Violet Queen’ (violet-blue).
Crocus speciosus has flowers 10-12cm (4-5in) high. They are bright lilac-blue with yellow anthers and red stigmas, and open in mid autumn. This species multiplies freely, making it the most popular autumn-flowering crocus. ‘Aitchisonii’ (pale lavender-blue) and ‘Conqueror’ (deep sky-blue) are varieties. A white form ‘Albus’ is sometimes also available.
Crocus susianus has star-shaped flowers standing 5-7.5cm (2-3in) high. They are bronze outside, and yellow inside, and appear in February. It is one of the oldest crocuses in cultivation.
Crocus tomasinianus has lilac flowers that appear in late winter, 7.5cm (3in) above ground. For a deeper mauve try ‘Whitewell Purple’. It is one of the best crocuses for naturalizing in grass.
Dutch hybrids have been developed from the species Crocus vernus and have large robust flowers in an enormous choice of colours. The flowers are goblet-shaped; they stand 10-12cm (4-5in) high, and open in early spring. Plant them in rough grass or a border where, left undisturbed, they will develop into dense clumps. Well-known varieties are ‘Enchantress’ (light blue), ‘Joan of Arc’ (white), ‘Pickwick’ (pale lilac), ‘Purpureus Grandiflorus’ (purple-blue), ‘Queen of the Blues’ (blue), ‘Remembrance’ (soft violet-blue), ‘Striped Beauty’ (white striped violet) and ‘Yellow Mammoth’ (golden yellow).
Plant crocuses as soon as the corms are available in early autumn, although the Dutch hybrids can wait until late autumn. Choose a sunny or partially shaded site with well-drained soil. Set the corms 5-7.5cm (2-3in) deep and 7.5-10cm (3-4in) apart in small clumps.
When the flowers are over, don’t dead-head. And avoid the temptation to remove the leaves – wait until they are yellow and can be pulled off easily without disturbing the corms in the soil.
When the leaves die down, lift the corms, remove any small cormlets and replant. Under good conditions C. tomasinianus and the Dutch hybrids multiply naturally.
Pests and diseases
Mice and leatherjackets sometimes eat corms in the soil. Watch out for birds pecking at young flower buds – especially yellow varieties.