Saffron crocus

Sun

Full sun; choose a position that stays sunny in autumn.

Water

Water moderately during autumn and winter growth if rainfall is insufficient. Keep nearly dry during summer dormancy and never leave the soil waterlogged.

Soil

Well-drained sandy or gritty loam, preferably neutral to slightly alkaline. Use raised beds or containers where soil is heavy or winters are wet.

Height

0.3-0.5 ft (0.1-0.15 m)

Spread

0.2-0.3 ft (0.05-0.1 m) per corm, gradually forming wider clumps

Flowers

Autumn: lilac-purple flowers with darker veins, yellow anthers and three long red stigmas.

Foliage

Narrow, grass-like green leaves with a pale central stripe appear around flowering time and remain through winter into spring before dying back.

Growth

Seasonal growth is quick; clumps increase slowly to moderately through daughter corms.

Care needed

Medium

• Pollinators
• Heat tolerant
• Low allergen
• Edible

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   0.4 ft (0.13 m)

   full size

About 1 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Mildly toxic: may upset a stomach

Growth rate

Slow

• Plant dormant corms in late summer, about 4-6 in (10-15 cm) deep and 3-4 in (8-10 cm) apart.
• Water after planting, then supply moisture during active growth only when the soil begins to dry.
• Keep dormant corms dry in summer; avoid beds receiving frequent lawn or vegetable irrigation.
• Apply a light dressing of balanced fertiliser as growth starts if the soil is poor.
• Lift and separate crowded clumps during summer dormancy, usually every three to five years.

Pruning. Do not cut green leaves: they replenish the corms for the next flowering season. Remove foliage only after it has yellowed and dried in late spring or early summer.

Pick the three red stigmas from newly opened flowers on a dry autumn morning, using clean fingers or tweezers. Dry them promptly in gentle warmth until brittle, then store in an airtight container away from light; correctly identified saffron stigmas are the edible spice, not the corms.

Late summer

Plant purchased corms or lift, divide and promptly replant dormant clumps.

Early autumn

Resume modest watering as growth begins if rainfall is lacking.

Autumn

Harvest red stigmas from newly opened flowers and dry them for storage.

Winter

Keep leaves intact and check that beds and containers drain freely.

Spring

Allow leaves to keep growing; water during prolonged dry spells.

Summer

Remove fully dead foliage and keep dormant corms relatively dry.

• Plant in small drifts along sunny gravel paths where the low autumn flowers are easy to see.
• Use in a dedicated herb or spice bed where flowers can be identified and harvested safely.
• Grow in free-draining terracotta pots to control summer watering and bring flowers close to eye level.
• Place among widely spaced Mediterranean shrubs, leaving open sunny pockets for winter foliage.

Garden styles it suits: Mediterranean, Dry gravel garden, Potager (kitchen garden), Herb parterre, Edible landscape and Autumn colour.

Plant it with: Lavender, Creeping thyme, Rosemary and Bearded iris.

Wildlife: Bees may visit the autumn flowers for pollen. The plant is sterile and does not produce viable seed.

• Corm rot in wet soil: improve drainage, use raised beds and discard soft or mouldy corms.
• Mice, voles or squirrels eating corms: protect plantings with securely fitted wire mesh that allows shoots through.
• Slugs and snails damaging flowers: inspect during damp weather and use barriers or wildlife-conscious controls.
• Few flowers: provide more sun, avoid cutting green leaves and divide overcrowded clumps during dormancy; small daughter corms may need time to reach flowering size.

The red stigmas are edible in normal culinary quantities, but large doses of saffron can cause serious poisoning in people. Corms and other non-spice parts should not be eaten; ingestion may cause vomiting or diarrhoea in cats and dogs. Toxicity in horses is not well established, so prevent access. Do not confuse it with highly poisonous Colchicum species, also called autumn crocus.

• Autumn crocus or meadow saffron (Colchicum autumnale)

  Highly poisonous Colchicum has six stamens rather than the three found in true crocuses. Its broad leaves usually appear in spring, unlike saffron's narrow, striped leaves;

• Bieberstein's crocus (Crocus speciosus)

  Another purple autumn crocus, but its style divides into many fine orange branches rather than saffron's three long, deep-red stigmas. Its leaves generally appear in spring.

• Spring crocus (Crocus vernus)

  Flowers in late winter or spring rather than autumn and lacks saffron's three long, conspicuous red stigmas.

The Latin epithet sativus means cultivated or sown, reflecting its long history as a crop.

Propagation. Separate daughter corms during summer dormancy and replant promptly. This sterile species is propagated by corms, not seed; small offsets may take more than one growing season to flower.

Accepted botanical name

Crocus sativus

Native range

Greece.

Sources: GBIF (CC BY 4.0) and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.