Spring crocus

Crocus vernus

Cup-shaped purple, lilac or white spring bulb that opens in the first warm sun of the year. Critical pollen source for emerging queen bumblebees.

Hardiness ratings

Spring crocus hardiness across the four zone systems
SystemRatingTemperature rangeHow to read it
USDA hardiness zone Zone 3–8 −40 °C to −6.7 °C Plant tolerates down to this zone
RHS hardiness rating H7 down to −20 °C Plant needs at least this level of cold tolerance
Canadian plant hardiness zone Zone 3–8 −34 °C to −1 °C Plant tolerates down to this zone
Australian (ANBG) zone Zone 1–5 −15 °C to 10 °C Plant tolerates down to this zone

About Spring crocus

Crocuses are among the earliest bulbs to flower and are an important early nectar source, opening in response to warmth so that the flowers close again in cold or dull weather. The saffron crocus is a different, autumn-flowering species, and saffron is its dried stigmas — three per flower, hand-picked, which is the entire reason for its cost. Spring crocuses grow from corms rather than true bulbs, a solid stem base rather than layered scales, and they multiply steadily by producing new corms alongside the old.

Growing notes

  • Among the very first flowers of spring — a classic seasonal marker
  • Critical early pollen source for emerging queen bumblebees
  • Plant in drifts of a hundred or more for genuine pollinator value
  • Distinct from the autumn-flowering saffron crocus (C. sativus)

Categories

Related plants

Cross-check Spring crocus against your zones

Reference

Spring crocus on Wikipedia