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How to Grow Crocus sativus (Saffron Crocus)

Posted by Mr Middleton on 2nd Sep 2025

How to Grow Crocus sativus (Saffron Crocus)

Planting Timing

  • Best months:  September
  • Flowers appear in October–November, usually within 6–8 weeks of planting.
  • Plant promptly after purchase — saffron corms do not like sitting around.

Soil Preparation & Drainage

  • Requires well-drained, sandy or gritty soil.
  • Raised beds or pots are ideal in damp Irish gardens.
  • Work in a little lime if soil is acidic — saffron prefers neutral to slightly alkaline ground.

Depths & Spacing

  • Depth: 10–15cm deep
  • Spacing: 10–12cm apart
  • Plant in groups of 15–20 corms for a usable harvest.
  • In pots: use a free-draining mix (2 parts compost, 1 part grit/sand).

Variety & Flowering

  • Only Crocus sativus produces saffron threads.
  • Blooms are lilac-purple with three vivid red stigmas — these are harvested as saffron.
  • Flowers last only a few days, so daily checking is essential.

Harvesting & Cooking Value

  • Each flower produces 3 stigmas.
  • Harvest by hand early in the morning as blooms open.
  • Dry stigmas on paper in a warm, dry room for several days.
  • Store in a dark, airtight container — flavour deepens after 1–2 months.
  • It takes about 150 flowers to yield 1 gram of saffron, which explains its reputation as the world’s most expensive spice.

Cooking uses:

  • Adds golden colour and unique aroma to paella, risotto, bouillabaisse, and Persian rice dishes.
  • Infuse threads in warm water or milk before adding to recipes to release maximum flavour and colour.
  • Nothing beats the flavour of your own fresh harvested spice .

Naturalising Tips

  • Prefers sunny, sheltered spots.
  • Good for containers that can be kept drier in summer.
  • In the ground, plant in sandy ridges or raised beds.
  • Corms multiply each year if kept relatively dry in summer dormancy.

Pests & Problems

  • Rodents: Mice and squirrels may dig up corms — use wire mesh protection if needed.
  • Wet winters: Biggest risk — ensure very sharp drainage.
  • Low yields: Normal in the first year; improve with feeding after flowering.

After-Care

  • Allow foliage to grow over winter — it fuels the corms for next season.
  • Feed lightly with potash-rich fertiliser after flowering.
  • In pots: lift, dry and replant corms every 3–4 years.
  • In beds: divide and replant crowded clumps in late summer.

This week’s action:

  • Plant saffron corms in a sunny, free-draining spot by mid-September.
  • Harvest red stigmas as blooms open in October–November.
  • Dry and store threads to enjoy your own homegrown saffron in the kitchen this winter.