Crocus Bulbs

Buy crocus bulbs: the variety groups at a glance

Crocuses can be roughly divided into three groups. The early crocuses (Crocus tommasinianus) are dainty, flower very early and naturalise in lawns on their own. A proven variety is 'Ruby Giant' with purple-violet flowers. The large-flowered crocuses (Crocus vernus) flower a little later and have strong, large cups, for example the pure white 'Jeanne d'Arc'. The species crocuses such as Crocus chrysanthus or Crocus sieberi are small, often bicoloured and suit rock gardens and pots.

A special case is the saffron crocus (Crocus sativus). It flowers in autumn, and saffron is obtained from its red stigmas. It also thrives in Switzerland in warm, sunny, free-draining spots, as the well-known saffron growing in Mund in Valais shows. There are also other autumn crocuses such as Crocus speciosus.

Planting time and position in Switzerland

On the Swiss Plateau, plant spring-flowering crocuses from September to the end of November, as long as the ground is not frozen. At higher altitudes it pays to plant earlier so that the corms still form roots before the frost. Saffron and autumn crocuses go into the ground as early as August. Crocuses love sun to light partial shade and free-draining soil without waterlogging. Under deciduous trees they get enough light in spring. They are fully hardy.

Planting and caring for crocuses

• Planting depth: about 5 to 10 cm, on average around 8 cm
• Spacing: around 5 cm; for a dense carpet, plant in groups of 20 to 50 corms
• Height: about 10 to 15 cm
• Flowering time: February to April, autumn species September to October

After flowering, leave the foliage until it turns yellow, as this is how the corm builds up strength for next year. In a lawn this means: do not mow until the end of May. Watering is only necessary in pots. Crocuses multiply through offsets and seed, becoming denser every year. If mice are a problem, a wire planting basket helps.

Uses and combinations

Crocuses belong at the front of borders, in lawns, along the edges of shrubberies and in pots on the balcony. They combine beautifully with winter aconites, squills (Scilla) and early daffodils. Because they offer pollen and nectar very early, crocuses are valuable bee forage after winter. Crocuses are poisonous if eaten; the saffron crocus provides the spice only through its stigmas.