Dyeing Yellow with Marigold — The Sacred Aztec Flower Dye

Use 200-300% WOF of dried marigold flower heads (or 400-600% WOF of fresh flowers). For 100 g of wool, weigh out 200-300 g of dried flower heads. Use Tagetes erecta (African/Aztec marigold) for the deepest yellow — the large, double-petalled varieties contain the most lutein. Tagetes patula (French marigold) also works but gives slightly paler colour. The dried flowers should be deep orange-yellow. Avoid flower heads that have turned brown — they have lost much of their pigment.

Place the dried flower heads in the dye pot and cover with about 5 litres of warm water. Soak overnight (8-12 hours). The flowers will soften and begin releasing their pigments — the water will turn a warm golden-yellow during soaking. The overnight soak ensures that dried petals fully rehydrate and release their dye more completely during the subsequent simmering.

Bring the pot to a gentle simmer (80-85°C) and hold for 60 minutes. Stir occasionally, pressing the flower heads against the side of the pot to release more dye. The liquid will deepen to a rich, opaque golden-yellow. Do not boil vigorously — excessive heat can shift the colour from bright yellow toward muddy olive. After simmering, the spent flower heads will be pale and soft.

Strain the dye liquor through a fine mesh strainer into a clean pot. Squeeze the spent flowers to extract the last colour. The strained dye bath should be a clear, warm golden-yellow. Compost the spent flower heads. Flower fragments left in the dye bath during dyeing can lodge in the wool and cause uneven spots, so strain thoroughly.

Pre-wet the alum-mordanted wool, squeeze out excess, and lower it into the marigold dye bath at room temperature. Slowly raise to 85°C and hold for 45 minutes. Turn gently every 10 minutes. The alum mordant creates a stable complex with the lutein pigments, producing a bright, warm golden-yellow. The bath will gradually pale as the wool absorbs the colour.

Turn off the heat and let the wool cool in the dye bath overnight. Remove, squeeze gently, and rinse in lukewarm water. The final colour is a warm, bright golden-yellow — the colour of sunflowers, of autumn corn, of Mexican cempoalxóchitl garlands. Marigold yellow has moderate-to-good lightfastness — significantly better than turmeric, which fades quickly in sunlight. The colour will mellow slowly over months of sun exposure but does not wash out. An iron afterbath shifts marigold yellow to olive-green. Dry in shade.