When and how to harvest herbs: a seasonal checklist

Most failures with herbs happen not during drying or storage, but at the moment of harvest. A herb picked in the rain or in the midday heat will never smell as good as it could have. These are the rules I follow every season.

Weather and time of day

Harvest on a dry day, in the morning — after the dew has gone but before the heat sets in. Wet herbs take longer to dry and easily mold in a bunch. And in the heat of the day, aromatic herbs — mint, lemon balm, oregano, thyme — noticeably lose their scent: essential oils are volatile.

After a long spell of rain, wait a day or two for the plants to dry out.

What to take, and when

• Leaves — before flowering or right at its start. After that the plant puts its energy into flowers, and the leaves get tougher.
• Flowers — when most of the flower head has opened but the petals haven't started to drop.
• Seeds — as they ripen: cut dill and coriander when the umbels turn brown and finish drying them in a paper bag.
• Roots — in autumn, once the top growth has died back, or in early spring before it regrows.

Where to harvest

Your own garden or a remote meadow is best. Stay away from roads, railway lines and fields that get sprayed. Dust and exhaust settle on the leaves, and no amount of washing removes them completely.

Only what you know for sure

Many familiar herbs have look-alikes, and not all of them are harmless. This is especially true of the carrot family: poison hemlock is easily mistaken for cow parsley or wild carrot. The rule is simple and has no exceptions: if you're not sure, don't pick it.

How to cut

Use scissors or pruners rather than your hands: the roots stay undisturbed and the plant grows back quickly. Take only part of each plant or patch rather than stripping it bare, so there's something to harvest next year.

A basket, not a bag

In a plastic bag, fresh herbs start to sweat in under an hour. Take a basket or a canvas bag, and don't put off sorting: as soon as you're home, go through the harvest and lay it out to dry. More on that — in a separate post.