How to Dry Herbs and Flowers for Winter Use

Why Drying Still Makes Sense

By late September the hedgerows are beginning to close up shop. Elderberries are shrivelling, meadowsweet has gone to rust, and the nettles are tough enough to need gloves and a bit of patience. If you want that summer flavour in January — a spoonful of wild mint in a teapot, a pinch of dried yarrow in a winter infusion — now is the moment to preserve it.

Drying is the oldest preserving method in the book, and for good reason. It removes the water that mould and bacteria need, while leaving the aromatic oils and much of the nutritional value largely intact. The trick is gentleness. Heat it too hard and you cook off exactly the volatile compounds you were trying to save; dry it too slowly in a damp shed and it goes musty instead. Between those two extremes there is plenty of room to work.

What to Gather, and When to Stop

The general rule for leaves is to pick before the plant flowers, when the oils are most concentrated. Flowers should be taken just as they open, in dry mid-morning after the dew has lifted but before the sun has baked them. Roots are a late-autumn job; berries are best the moment they colour up.

Some reliable British favourites for the drying rack:

• Leaves: nettle, wild mint, lemon balm, blackberry leaf, raspberry leaf, yarrow, mugwort, plantain, hawthorn.
• Flowers: elderflower, meadowsweet, chamomile, red clover, lime blossom, wild rose petals, marigold.
• Berries and hips: hawthorn, rosehip, elderberry — these dry better halved and finished in the oven.

Pick only from clean ground well away from roadsides and sprayed field margins, take no more than a quarter of what you find in any one patch, and never take anything you cannot identify with complete certainty. Roots and bark need the landowner's permission; on common land, keep to the "four Fs" of foraging custom — fruit, foliage, fungi and flowers — and leave the rest.

Air-Drying: The Slow, Kind Method

Air-drying suits anything with a decent oil content and a thin structure: mint, lemon balm, yarrow, meadowsweet, rose petals, nettle. It takes a week to a fortnight in a warm, dark, airy room, and it costs nothing but patience.

For leafy stems, cut them in the morning, shake off any insects, and remove the lower leaves. Tie four or five stems together with string and hang them upside down — from a beam, a curtain rail, a clothes airer — somewhere out of direct sunlight with a good through-draught. A dark spare room or an airing cupboard with the door cracked open works well.

Larger flowers and petals need a different approach. Spread them in a single layer on a muslin or paper-lined tray, petals face up so they do not bruise, and turn them gently every day or two. Meadowsweet and elderflower dry quickly; rose petals and clover take longer and will brown if they sit in a heap.

If you live somewhere humid, a short spell in a very cool oven — 40°C, door propped open, with a wooden spoon to hold it ajar — will finish the job and stop anything going mouldy.

Gentle Oven and Dehydrator Drying

Some things are simply too fleshy or too damp for air-drying in a British autumn. Roots, berries, hips, and thick leaves such as comfrey and plantain do better with a little warmth.

Set your oven to its lowest setting — no more than 50°C, and lower if you can manage it. Spread the prepared material thinly on baking parchment. Leave the door slightly open to let moisture escape, and check every twenty minutes. Nettle and mint take an hour or two; halved rosehips and elderberries may take four or more. They are ready when a leaf crumbles rather than bends, a berry rattles in the hand, and a root snaps cleanly.

A dehydrator is simply a patient oven. Run it at 40–45°C for leaves and flowers, 50°C for roots and berries. Whichever method you use, do not try to hurry it. The oven door open and the fan running is a far better guarantee of quality than a higher temperature.

Conditioning, Storing and Labelling

Before anything goes into a jar, condition it. Fill a clean glass jar loosely with your dried material, seal it, and leave it on the shelf for a week. If condensation beads on the inside of the glass, there is still moisture in the plant — tip it back out onto a tray and dry it further. This step catches the batch that would otherwise turn to mould in February, and it costs you nothing but a little time.

Once conditioned, store in airtight glass jars out of direct light. Whole leaves and flower heads keep their aroma far longer than crushed ones, so leave them intact and crush as you use them. Label everything with the plant name and the month and year it was gathered. A jar of anonymous green flakes is no use to anyone, least of all you in six months' time. Most leafy herbs hold well for a year; roots and berries will keep for two.

Putting Your Store to Work

Dried herbs earn their shelf space in simple ways. A heaped teaspoon of dried nettle or lemon balm in a mug of just-boiled water, covered for ten minutes, makes a decent everyday infusion. A teaspoon of dried meadowsweet or elderflower lightens a winter tea and takes the edge off a cold. Keep a few jars of dried rose petals and marigold for salves and oils, and blend dried mint, rosemary and thyme with coarse sea salt for a foraged seasoning that will see you through to spring.

Above all, use them. A store cupboard of hedgerow herbs is only worth keeping if it ends up in the pot, the teapot or the bath. Start with one or two things you know well, dry them properly, and let the rest of the season come to you.