Natural Dyeing with Onion Skins and Nettles

Why Dye with Kitchen Scraps and Weeds?

There is something deeply satisfying about pulling a bundle of wool from a steaming pot and watching it turn the colour of burnt honey or mossy green. Natural dyeing sits at the heart of rustic living: it asks you to look at what is already around you — the papery skins from a bag of onions, the nettles colonising the corner of the yard — and see colour rather than waste.

You do not need a dedicated studio. A large stainless steel pan, a wooden spoon you keep for dyeing only, and a heat source will do. Once you have the basics of preparing fibre, extracting colour, and fixing it with a mordant, you can dye wool, cotton, linen, and silk with ingredients that would otherwise go on the compost heap.

A word of caution before you begin: keep dye pots and utensils strictly separate from those used for food, work in a well-ventilated space, and never use aluminium pans with plant dyes, as the metal reacts and dulls results.

Gathering and Preparing Your Materials

Onion skins are the beginner's best friend. The dry outer layers of brown or yellow onions give warm, coppery oranges and tans; red onion skins shift towards olive and soft bronze. Keep a paper bag in the kitchen and add skins as you cook. Around 100g of dry skins will dye roughly 100g of fibre to a good depth. There is no need to wash them — just avoid any that are mouldy.

Nettles should be gathered young, ideally in spring before they flower, when the colour is strongest. Wear thick gloves, take the top four to six leaves of each plant, and cut rather than pull so the roots survive. You need roughly the same weight of fresh nettle tops as dry onion skins, or about half that if you dry them first. Nettles give soft greens and, with an iron modifier, deep grey-blues.

Prepare your fibre before dyeing. Wool should be scoured — gently washed in hot water with a little pH-neutral soap to remove lanolin and dirt — and never agitated, or it will felt. Cotton and linen need a longer boil to open the fibres. Always wet your fibre thoroughly before it goes into the dye bath so the colour takes evenly.

Making the Dye Bath

For onion skins, place them in your pan, cover with plenty of water, and bring to a gentle simmer for about an hour. The liquid should turn a rich amber. Strain out the skins and compost them; what remains is your dye bath.

For nettles, chop the leaves roughly and simmer for 45 minutes to an hour. The water will look disappointingly brownish-green at first — do not panic, the colour develops on the fibre. Strain and discard the plant matter.

• Use soft or rainwater if you can; hard water dulls plant colours.
• Keep the bath at a simmer, never a rolling boil, especially with wool.
• Roughly one part plant material to one part dry fibre by weight is a reliable starting ratio.
• Save exhausted baths — they often give delicate pastel shades on a second batch of fibre.

Mordants: Fixing the Colour

A mordant is what binds the dye to the fibre so it does not wash straight out. The traditional and safest choice for home dyeing is alum (potassium aluminium sulphate), often used with cream of tartar. For 100g of fibre, dissolve around 10g of alum and 5g of cream of tartar in hot water, top up the pan, add your wet fibre, and hold at a gentle simmer for an hour. Let it cool in the liquid, then rinse.

You can mordant before dyeing, which gives the most even results, or add the mordant directly to the dye bath. Pre-mordanting is the method most smallholders settle on because it is predictable.

Iron is a modifier rather than a true mordant, and it "saddens" colours — turning onion-skin orange into a deep russet and nettle green into slate blue. Make it by soaking rusty nails in a jar of water and vinegar for a week. Add a small splash to the dye bath at the end, watch the colour shift, and stop when you are happy. Go gently: too much iron makes wool brittle.

Dyeing and Aftercare

Add your mordanted, wet fibre to the strained dye bath. Bring slowly to a simmer and hold for 45 minutes to an hour, stirring gently and infrequently. Turn off the heat and, ideally, leave the fibre to steep overnight — this deepens the colour considerably.

Rinse in water of gradually decreasing temperature until it runs clear, then wash gently in cool water with a little pH-neutral soap. Dry in the shade, away from direct sun, which fades natural dyes. Expect some softening over time; that is part of the character of naturally dyed cloth.

• Keep notes of weights, times, and quantities — natural dyeing rewards record-keeping.
• Dye similar fibres together; wool and cotton take up colour at different rates.
• Store finished skeins out of direct light to preserve the shade.

Once you have mastered these two staples, you will find yourself eyeing the hawthorn berries, the walnut husks, and the marigold heads in your garden with fresh eyes. Every hedgerow becomes a palette, and every kitchen scrap a possibility.