Coriander

About Coriander

Coriander is a fast-growing annual herb native to the Mediterranean and Middle East, prized for its aromatic leaves and seeds. The delicate, lacy foliage has a distinctive citrus-like flavour that divides opinion, whilst the round seeds offer warm, spicy notes essential to curries and pickles. UK gardeners value coriander as a dual-purpose crop that thrives in cool conditions, making it ideal for spring and autumn sowings when many herbs struggle. Both leaves and seeds are staples in British home cooking, from Asian-inspired dishes to traditional pickling spice blends.

UK fact: Coriander has been found in archaeological sites across Britain dating back to Roman times, when it was used both as a culinary herb and to mask the taste of preserved meats in the days before refrigeration.

Watering Coriander

Coriander requires regular watering to maintain steady growth and prevent the plant from bolting prematurely in response to drought stress. Water two to three times weekly during dry periods, ensuring the top 5cm of soil remains evenly moist but never saturated. Container-grown plants dry out more quickly and may need daily watering in warm weather. Reduce watering slightly once plants begin to flower if you're growing for seed, but never allow the soil to dry out completely as this produces bitter-tasting leaves and reduces seed yield.

Sunlight requirements

Position coriander in full sun during spring and autumn for the best leaf production, ideally receiving at least four to six hours of direct light daily. In summer, particularly in southern England, provide light afternoon shade or grow in a north-facing spot to keep plants cooler and delay flowering. Container-grown coriander can be moved to shadier positions as temperatures rise, extending the harvest period considerably.

Soil and feeding

Grow coriander in fertile, well-drained soil with plenty of organic matter to retain moisture whilst preventing waterlogging. A neutral to slightly alkaline pH of 6.5 to 7.5 is ideal, though the plant tolerates a range of soil types provided drainage is adequate. Heavy clay soils benefit from the addition of horticultural grit and compost to improve structure, whilst sandy soils should be enriched with well-rotted manure or garden compost to boost moisture retention. For container growing, use a peat-free multipurpose compost mixed with 20% perlite or vermiculite for improved drainage.

Apply a balanced liquid fertiliser diluted to half strength every three weeks if growing coriander primarily for leaf production, particularly in containers where nutrients leach more quickly. Plants grown in the ground in well-prepared soil rarely need supplementary feeding. Avoid high-nitrogen feeds once flowering begins if you're growing for seed, as excessive nitrogen promotes leafy growth at the expense of seed development.

Pruning Coriander

Pinch out the growing tips once plants reach 10-15cm tall to encourage branching and a bushier habit, which increases leaf yield. Harvest outer leaves regularly, taking no more than one-third of the foliage at a time to keep plants productive. Remove any flower stems as soon as they appear if you're growing for leaves, though this only delays bolting temporarily in warm weather. If growing for seed, allow plants to flower freely and remove only damaged or yellowing foliage until seed heads have fully matured and turned brown.

Propagating Coriander

Sow coriander seeds directly into the ground or containers from March to September for a continuous supply, making small sowings every three weeks to ensure fresh leaves throughout the season. The plant develops a long taproot and resents transplanting, so avoid starting in modules unless using deep root trainers. Seeds germinate best at soil temperatures between 7-20°C, with cooler conditions producing slower but sturdier growth less prone to bolting. For winter crops under cover, sow in September or early October in an unheated greenhouse or polytunnel.

Common problems

Coriander is relatively trouble-free but prone to bolting (premature flowering) in hot, dry conditions or when root-bound, which makes leaves bitter and ends leaf production. Aphids occasionally colonise young growth, particularly in warm weather, and can be controlled with insecticidal soap or by encouraging natural predators such as ladybirds and hoverflies. Slugs and snails may damage seedlings in damp conditions, so protect young plants with organic slug pellets or copper barriers. Powdery mildew can affect plants in late summer, particularly those under stress from drought or overcrowding, though good spacing and adequate watering usually prevent problems.

Spot a problem with your plant? Photograph the affected area using the Loam app and it will suggest the most likely cause and treatment.

Safety

Humans

Safe

Cats

Safe

Dogs

Safe

Toxicity information is for general guidance only.

Seasonal care calendar

Monthly care guide for Coriander in the UK, based on average conditions.

Frequently asked questions

Why does my coriander keep bolting before I can harvest much?

Coriander bolts in response to heat, drought, or root disturbance. Sow in cooler months (spring and autumn), keep soil consistently moist, provide afternoon shade in summer, and make small succession sowings every three weeks rather than one large planting.

Why are my coriander leaves turning yellow?

Yellowing coriander leaves can indicate overwatering, nutrient deficiency, poor drainage, or pest problems such as aphids. Check soil moisture levels and ensure pots have adequate drainage holes. If you're struggling to diagnose the issue, the Loam app can help identify the specific problem through photo analysis and provide personalised care recommendations based on your growing conditions.

What type of soil does coriander need?

Coriander thrives in well-draining, fertile soil with a pH between 6.2 and 6.8. Mix in organic matter such as compost before sowing to improve soil structure and nutrient content. For container growing, use a quality multipurpose compost mixed with perlite or grit to ensure good drainage. Avoid heavy clay soils that retain too much moisture, as these can cause root rot and poor growth.

Related plants

• Parsley
• Dill
• Basil
• Chervil
• Fennel