How to Harvest Coriander Leaves, and How to Save the Seed

Start cutting sooner than you think

Coriander is ready when the plant is about six inches (15 cm) tall and has five or six true leaves, usually three to four weeks after sowing in warm weather and five to six in a cool spring. There is no benefit in waiting for a bigger plant. The leaf you leave on a plant in early summer is leaf you will lose to bolting.

Cut the outer stems right down at the base with scissors, taking no more than a third of the plant at a time. The growing point sits low in the center, so cutting from the outside leaves it intact and the plant keeps producing. Shearing across the top removes that center along with the leaves and the plant either stalls or throws up a flower stem.

1. Take the outer stems first Work from the outside in, cutting each stem at soil level. The older outer leaves are the ones that will yellow first anyway, so you lose nothing.
2. Never take more than a third A plant stripped bare regrows slowly and often bolts instead. Cutting a third every week from three or four plants gives more leaf than stripping one.
3. Cut in the morning Leaves cut before the sun is on them are crisp and keep two or three days longer than leaves cut in the afternoon heat.
4. Clear a bolting plant in one go Once the feathery leaves appear, cut the whole plant at the base and use it. Leaving it in the ground only shades the next sowing.

Coriander leaf does not improve with age on the plant. If you have more than you can use, cut it and freeze it rather than leaving it standing.

How long a plant keeps giving

How many cuts you get is decided almost entirely by the season, not by technique. Knowing the realistic number stops you nursing a spent plant when you should be sowing another row.

An autumn sowing under a cloche or in a cold frame will stand for months and can be cut lightly all through the cool season. It is the closest thing to a continuous supply.

Keeping the cut leaf

Coriander leaf wilts within hours at room temperature and turns black in a cold fridge drawer. Treat it as a cut flower instead: stand the stems in an inch (2 cm) of water in a jar, cover the leaves loosely with a bag and keep it in the door of the fridge rather than the coldest shelf. It will hold a week that way against two days loose in a bag.

Drying is not worth doing. Dried coriander leaf loses almost all its aroma and tastes of hay. Freezing keeps far more: chop the leaves, pack them into an ice cube tray with a little water or oil, and drop a cube straight into cooking. The texture is gone but the flavor is largely intact.

1. Wash only what you are about to use Wet leaves rot in storage. Cut clean, store dry, and rinse at the point of use.
2. Use the stems The stems carry more flavor than the leaves and stand up to heat. Chop them finely and add them early in cooking, keeping the leaf for the end.
3. Freeze in usable portions A tablespoon per cube is about right. Loose frozen leaf packs into a solid lump you have to hack apart.

Harvesting the seed

Let one sowing run to flower on purpose. The white or pale pink umbels are worth having for the hoverflies and parasitic wasps they bring in, and the seed that follows is coriander spice, which is a different crop from the leaf and far better fresh from your own plants than from a jar.

The seed is ready when about three quarters of the heads have turned from green to a pale tan brown and the first few seeds shatter at a touch. Do not wait for every head to ripen. Coriander drops its seed the moment it is fully dry, and a week of hesitation costs you most of the crop to the ground.

1. Cut whole stems on a dry morning Cut the flowering stems near the base once the dew has gone. Handle them gently and carry them upside down inside a paper bag so nothing shatters on the way in.
2. Dry them head down in a paper bag Tie the stems in small bundles, put the heads into a paper bag and hang it somewhere dry and airy for one to two weeks. The seed falls into the bag as it finishes drying.
3. Thresh and winnow Rub the dry heads between your palms over a bowl, then pour the mixture from one bowl to another in a light breeze or in front of a fan. The chaff blows away and the round seed stays.
4. Dry a further week before storing Spread the cleaned seed one layer deep on a tray for another week. Seed jarred while still slightly damp goes musty within a month.
5. Store in a jar in the dark An airtight jar in a cool, dark cupboard keeps the aroma for a year for cooking. The same seed stays viable for sowing for three to four years.

Toast the seed briefly in a dry pan before grinding. Home dried coriander seed has a citrus note that shop bought ground coriander has usually lost entirely.

Volunteers, and what to record

Whatever you save, some seed will always hit the ground, and coriander self sows readily. Those volunteers are often the best plants you get: they germinate exactly when the soil suits them and, never having been moved, they stand in leaf longer than anything you sowed. Thin them to spacing rather than hoeing them off.

Note the date you cut each plant for the first time, the date you cut the last of it, and the date you harvested seed from the plants you let run. Over two seasons those dates show you the real length of your coriander season, and the seed harvest date tells you when next year's volunteers will appear.

1. Log the weight or volume of seed A single healthy plant yields roughly a quarter to half an ounce (7 to 15 g). Knowing that tells you how many plants to let flower next year.
2. Mark where you let plants go to seed That patch will come up thick the following season. Noting it stops you sowing a new row on top of a free one.
3. Keep seed from the plants that bolted last Save from the individuals that stood in leaf longest, not from whichever plant is most convenient. A few seasons of that makes a noticeable difference.