The Key Challenge: Coriander Bolts Quickly

Coriander (also called cilantro) is notorious for bolting — rapidly sending up a flower stalk and going to seed rather than producing leaves. This is triggered by heat, stress, or long daylight hours. Once it bolts, leaf production stops. Managing this is the main challenge of growing coriander.

Getting Started

  1. 1

    Sow seeds directly — do not transplant

    Coriander has a sensitive taproot and hates being transplanted. Sow seeds directly into the final pot or garden bed rather than starting in seed trays and moving later. Crush the seeds slightly between your fingers before sowing — each coriander “seed” is actually a small fruit containing two seeds, and crushing improves germination.

  2. 2

    Use a wide, deep pot

    Coriander has a long taproot. Use a pot at least 20cm deep and as wide as possible — a wide shallow pot dries out too quickly. Fill with quality potting mix. Sow seeds 1cm deep and 5cm apart. Water gently. Germination takes 7–14 days.

  3. 3

    Position in morning sun, afternoon shade

    In Australian summers, full all-day sun triggers bolting rapidly. Morning sun with afternoon shade, or a spot that gets 4–6 hours of sun, helps keep the plant in leaf-producing mode longer. In cooler seasons, full sun is fine.

  4. 4

    Water consistently — do not let it dry out

    Dry soil stress is one of the most common triggers for bolting. Keep the soil consistently moist but not waterlogged. Water when the top 1cm feels dry. In summer, this may mean daily watering.

  5. 5

    Harvest outer leaves regularly

    Harvest from the outside in, taking the largest outer leaves and leaving the centre to continue growing. Regular harvesting encourages the plant to keep producing leaves. Never take more than a third of the plant at once.

  6. 6

    Sow new seeds every 3–4 weeks (succession sowing)

    The most effective way to always have coriander. Even with perfect care, plants bolt eventually. Succession sowing — planting a new batch every few weeks — ensures you always have plants at the productive leaf stage.

If your coriander boltsLet it flower and set seed. The flowers attract beneficial insects. Collect the seeds (dry them for a week after harvesting) and use them as a spice (ground coriander seed) or replant them. The cycle continues.

Frequently Asked Questions

The most common causes: too much heat or direct sun (move to a cooler spot or provide afternoon shade), inconsistent watering causing stress (keep soil evenly moist), pot too small (roots restricted and stressed), or the variety — some varieties are more bolt-resistant. Look for “slow-bolt” varieties like Calypso or Leisure when buying seeds.
Yes, but it needs a genuinely sunny windowsill (south-facing, full sun). Insufficient light produces weak, leggy plants with poor flavour. A grow light helps significantly in winter. Indoors, temperature is more consistent, which reduces bolting compared to hot outdoor conditions in summer.