Coriander boltsA plant switching early into flowering and seed production, usually triggered by stress, after which leaves, roots or bulbs turn bitter or unusable. Full page → in hot, dry weather, flowering and ending the leaf harvest, and a cold spell or a change in day length can set it off too. A cool summer doesn't protect it, so the variety is worth choosing for how slowly it bolts.

Quick answer

Calypso for a long leaf harvest, or Cruiser if you grow in a pot: both are slow to bolt. Confetti for a milder, slightly sweet leaf, and Filtro for plentiful leaves.

What Scotland means for the choice

Coriander grows quickly, with harvests in as little as ten weeks, and it dislikes being transplanted, so sow it directly outdoors from spring onwards, or in containers. Plants tend to bolt in hot, dry weather, so for a summer leaf crop sow in a cooler spot out of midday sun and water in dry spells, and sow small batches every month or so. Calypso and Cruiser are slow to bolt, which buys time in a hot, dry spell. A cold snap or the change in day length can still set any variety off, which is why small, regular sowings matter as much as the variety. The coriander growing guide covers sowing, leaf and seed harvests and slug protection.

A bushy, leafy coriander plant next to a taller bolted coriander plant with white flowers and forming seed heads
A leafy plant (left) and a bolted one setting seed (right).
VarietyHardinessHabit and leafKnown for
CalypsoH2The RHS's H1a–H7 scale for how much cold a plant can survive outdoors, H1a being tender indoor-only and H7 hardy anywhere in the UK. Full definition →Upright, clump-forming; large, bright green leavesSlow to bolt; long cropping period, especially in summer
CruiserH2Upright, tidy; large, tasty leavesSlow to bolt; suited to containers
ConfettiH5Finely dividedPropagating a clump-forming perennial by digging it up and splitting it into several smaller pieces, each with roots and shoots attached. Full definition →, carrot-like foliageMilder, with a slight sweetness; leaves and seeds used
FiltroH2Upright, vigorous; bright green leavesHigh yielding throughout the season

All four hold the RHS Award of Garden Merit (AGMThe RHS's Award of Garden Merit: a UK-wide trials award for reliable performance, not a Scotland-specific recommendation. Full definition →).

Calypso and Cruiser: slow to bolt

Calypso is an upright, clump-forming annual with relatively large, aromatic, bright green leaves. It's slow to bolt, with a long cropping period, especially in summer. Cruiser is a popular, upright annual with excellent-tasting, aromatic foliage and a tidy habit that suits container growing. It's also slow to bolt.

Confetti and Filtro

Confetti has strongly aromatic, finely divided, carrot-like foliage with a milder flavour and a slight sweetness, and it's the hardiest of the four, at H5. Both its leaves and its seeds are used in cooking. Filtro is an upright, vigorous variety with aromatic leaves and plentiful harvests through the season. For the longest leaf harvest, Calypso or Cruiser is the better bet.

Leaf or seed?

Some varieties have been bred for a longer leafy harvest, and for leaf the slow-bolting Calypso and Cruiser are the ones to pick. If a plant does bolt, it isn't a total loss: the flowers are edible in salads, and the seeds that follow can be used green and unripe, when they taste milder, or once ripe and brown. Confetti's leaves and seeds are both used. If seed is what you mainly want, sow in spring or early summer.

Buying coriander

Seed is easy to find in garden centres and online, and garden centres sometimes sell potted plants in late spring and summer. Supermarket pots are a different thing: they're crowded with thin seedlings meant for picking over a short time, so keep them indoors and use them up rather than planting them out. Coriander doesn't last long on a windowsill either, turning pale in low light and bolting. It does grow well in an outdoor container, because it likes free drainageSoil that lets water pass through quickly rather than pooling, so roots aren't sitting in wet ground after rain. Full definition →, and Cruiser's tidy habit suits a pot.

Which one for your situation

  • A long leaf harvest in open ground: Calypso.
  • A pot or small bed: Cruiser.
  • A milder, slightly sweet flavour: Confetti.
  • Plenty of leaf: Filtro, removing flower stems as they appear.

Common questions

Which coriander is slowest to bolt?

Calypso and Cruiser are both slow to bolt. Calypso also has a long cropping period, especially in summer.

Why has my coriander flowered so early?

Hot, dry weather, a cold spell or changes in day length can all trigger it. Sow in a cooler spot out of midday sun, water in dry spells and remove flower stems to prolong leaf harvests.

Can I plant out a supermarket pot of coriander?

Not really. Supermarket pots hold lots of thin, overcrowded seedlings meant for short-term picking, so keep them indoors in a container and use them up. For a garden crop, sow seed.

Can I transplant coriander?

It dislikes being transplanted and can become leggyDescribes a plant that's grown tall, thin and sparse rather than bushy, usually from too little light or not being pinched out. Full definition → if kept indoors too long, so sowing directly outdoors is best.

Sources

Show the 5 sources