Cilantro & Coriander
Coriandrum sativum
It bolts. It always bolts. Plan for it rather than fighting it.

Accept the bolting
Cilantro runs to seed quickly in warmth and long days, and no variety truly prevents it - "slow bolt" types buy you perhaps a week or two. The practical answer is succession: sow a short row every two to three weeks from early spring through autumn, and treat each sowing as disposable.
Direct sow, never transplant
It has a taproot and resents disturbance, and transplant shock triggers - inevitably - bolting. Sow in place half an inch deep. The "seed" is actually a husk containing two seeds; gently crushing it before sowing improves and speeds germination.
Cool weather and some shade
Spring and autumn are the real seasons. In summer, afternoon shade and consistent moisture extend the leaf harvest meaningfully, though heat will win eventually.
Two crops from one plant
When it bolts, let it. The green seed is excellent - citrusy and quite different from either the leaf or the dried spice - and the fully dried seed is coriander, which is easy to harvest and stores for years. A plant that bolts is not a failure, it is a change of crop.
Harvest the leaves properly
Cut outer stems at the base rather than shearing the top, and take no more than a third at a time. Once the plant sends up a central flowering stem the leaves become feathery and much less flavourful.
It self-sows readily
Let a few plants shed and you will have volunteer cilantro appearing for years, often at better times than you would have sown it. Many growers deliberately allow a patch to naturalise.
Pests and disease
Very few. Aphids sometimes cluster on flower heads - which is fine, since the flowers also attract large numbers of beneficial hoverflies and parasitic wasps, making cilantro a genuinely useful insectary plant. Bacterial leaf spot occurs in wet weather.
Harvest and storage
Fresh leaves keep about a week standing in water in the fridge with a bag over them. Cilantro dries very badly - it loses nearly all flavour - so freeze it chopped in oil or water instead. For coriander seed, cut whole heads when they turn tan and dry them in a paper bag, then rub out and store airtight.
- Days to harvest
- 30-45 leaf
- Spacing
- 4-6 in
- Sun
- Full to part
- pH
- 6.0-7.0
- Bolts above
- ~75F
- Sow
- Direct, succession
- Seed harvest
- 90-105 days
- Frost
- Tolerates light frost