Puzzled About Fall-Blooming Crocus?

Fall-blooming crocuses look nearly identical to their spring-blooming cousins, so their sudden appearance in the autumn garden often causes some puzzled double-takes.

Several crocus species bloom in fall, but one with especially large and showy flowers is Crocus speciosus. It blooms in early to mid autumn, producing cup-shaped blue-violet flowers with showy orange styles in the center. Its grassy foliage emerges after the flowers. Fall-blooming crocus multiply both from seed and corm offsets and will naturalize under favorable growing conditions. Grow them in rock gardens or perennial beds, or naturalize them in the lawn.

Common name: Fall-blooming crocus

Botanical name: Crocus speciosus

Plant type: Bulb (corm)

Zones: 4 to 8

Height: 4 to 6 inches

Family: Iridaceae


Growing conditions

  • Sun: Full sun
  • Soil: Well-drained loam or sandy loam
  • Moisture: Avoid watering during the summer when bulbs are dormant.

Care

  • Mulch: None
  • Pruning: None
  • Fertilizer: Work in bonemeal or other phosphorus fertilizer before planting bulbs; apply a balanced fertilizer in early spring.

Propagation

  • Dig, divide and replant bulbs when clumps get too crowded.


Pests and diseases

  • None

Cultivars

  • ‘Cassiope’ has light blue-violet flowers with yellow throats.
  • ‘Oxonian’ has blue-violet flowers with darker veining.
  • ‘Conqueror’ has deep blue-purple flowers.
  • formaalbus (also listed as cultivar ‘Alba’ or ‘Albus’) has white flowers.

Garden notes

  • Fall-blooming crocus flowers have long, thin, tubular bases that tend to flop over, so it’s a good idea to plant the corms within a patch of groundcover plants like perennial geraniums or short sedums that can support the crocus.
  • Fall-blooming crocus prefer dry conditions in summer followed by increasing moisture in early fall.
  • To get a better view of the delicate flowers, plant in raised beds, rock gardens or the top row of terraced gardens.

All in the family

  • Fall-blooming crocus is a member of the iris family (Iridaceae).
  • Other popular garden plants in the iris family include iris, gladiolus, freesia and harlequin flower (Sparaxis tricolor).


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