Why Autumn Is the Dyemaker's Busiest Season

There is a fortnight in early October when everything in the garden seems to be simultaneously finishing and offering itself up. The marigolds are sprawling across the path, the dahlias are on their last flush, and the kitchen windowsill is quietly accumulating a small mountain of onion skins. It would be easy to compost the lot and turn to other things. Please don't. A few hours of collecting and drying now will keep your dye pots going through January, when there is nothing much growing and the light is too poor to do anything else.

Winter is, in fact, the best time for dyeing. The garden asks nothing of you, the kitchen is warm anyway, and there is something deeply satisfying about coaxing gold out of a paper bag of dried petals while rain runs down the window. All it takes is a bit of forward planning in the autumn.

What Is Worth Collecting

You do not need a dedicated dye garden to build up a good store. Some of the most reliable dyes come from things you were going to throw away.

• Marigold heads — both pot marigold and the French and African types. Pull the heads apart into petals, or keep them whole if you are short of time. They give a warm, glowing yellow.
• Onion skins — brown and yellow skins give gold through to tan and soft orange; red skins shift greenish over an iron modifier.
• Avocado stones — wonderfully generous for a kitchen waste, giving anything from a pale blush to a dusty rose, depending on quantity and fibre.
• Anything else going over — dahlia flowers, coreopsis, tansy, fennel, nettle tops, acorn caps, alder cones and oak galls all dry well and dye beautifully.

Collect in dry weather, ideally mid-morning once any dew has lifted. Damp plant material is the enemy of good storage.

Drying Marigolds, Onion Skins and Avocado Stones

The golden rule is simple: get everything bone dry before it goes anywhere near a bag. Material that still feels cool or leathery will grow mould in a cupboard, and a mouldy bag of petals will ruin everything stored beside it.

Marigold heads dry quickly if spread in a single layer on newspaper, an old cake rack or a mesh tray. Keep them out of direct sun, which fades colour, and somewhere warm and airy — a spare room, the top of a cupboard, a windowsill that does not catch full sun. Turn them daily. Whole heads take about a week; loose petals two or three days. They are ready when they feel papery and crush easily between your fingers.

Onion skins are already dry when they come off the onion, so they need very little. Spread them out for a day or two to make sure there is no dampness, and discard any that are soft or mildewed. This is a good job to do while dinner is cooking.

Avocado stones need the most attention. Wash them well, then leave them on a rack in a warm, airy spot for two to three weeks, turning occasionally. They are ready when they feel light and rattle slightly. If you are short of drying space, they freeze perfectly well and can be used straight from the freezer. Chopping dried stones into smaller pieces is worth the effort — they release colour far more readily.

Packing and Labelling for the Winter Months

Brown paper bags are ideal. They breathe, so any last trace of moisture escapes, and they are cheap and easy to label. Plastic bags and sealed jars trap damp and are best avoided unless you are absolutely certain the contents are dry.

Label each bag with the dye material and the date. It sounds fussy, but by February you will not remember whether that pale bag holds tansy or fennel, and the distinction matters. Store the bags in a lidded box in a dark, dry cupboard. If your house runs damp, tuck a small sachet of silica gel in the box and check the contents every few weeks.

How Much to Keep Back

As a rough guide for 100g of fibre: about 100g of dried marigold petals gives a good clear yellow, roughly the same weight of onion skins gives a solid gold, and six to eight avocado stones give a soft pink that deepens with more. Dried materials tend to be a little weaker than fresh, so allow perhaps ten to twenty per cent more than you would use in summer. Do not worry about precision — keep notes of what you used and what came out, and you will soon develop your own instincts.

Planning Your Cold-Weather Dye Pots

Sort your bags by colour family as they build up — yellows together, browns and greys together, pinks and reds together. Then, when a grey January afternoon arrives and you fancy a day at the stove, the decision is already half made. Simmer your dried material gently for an hour or so before straining, give it a good long soak if you have the patience, and remember that ventilation matters more than ever when the windows are shut.

There is a real pleasure in this small act of banking away colour. The garden gives you a summer's worth of dye in a fortnight of collecting, and the winter gives you the time to use it.