At this time of the year many gardens are full of the glorious, vivid, glowing colours of dahlia flowers. To me they seem the floral echo of the wonderful autumnal shades of the leaves on the trees – the last flash of colour before the onset of winter.
As a dyer, these dahlia flowers are also a source of brilliant yellows, oranges & golds. With the exception of white flowers, which don’t yield much colour, all colours of flowers give similar shades & can be mixed together in the dyepot. The leaves give interesting green-brown shades, so to get the most out of the plants use the leaves for a separate dyebath, rather than adding them to the dyepot with the flowers. You don’t need to sacrifice the best flowers from the garden or flower vase – just wait until the flowers have faded & “gone over”, then remove them from the stalks. You need about the same weight of flowers (or leaves) to fibres for the most brilliant colours. You can use them fresh or dried, preferably with an alum mordant for full shades. After dyeing, the use of an alkaline modifier or after-bath will give vivid oranges. Just dissolve 2 or 3 teaspoons of washing soda crystals in boiling water, add this to cool water in a pot & soak the dyed fibres for half to 1 hour. DON’T heat, especially if dyeing animal fibres, as the alkaline solution may damage them. An iron after-bath will give mossy-green tones. Use half to 1 teaspoon of ferrous sulphate, dissolved in hot water then added to cool water, as described for washing soda. You can either soak the fibres in this for 10 to 30 minutes, or heat gently. You can also make your own iron water by soaking rusty nails or scrap iron in a solution of 1 part water to 1 to 2 parts clear vinegar. When the liquid looks rusty in colour, usually after 2 or 3 weeks, it’s ready to use. Just add a cupful of iron water to warm water & continue as above. Dispose of the used plant materials on the compost heap & remember that acid-loving plants or broad-leaved evergreens, such as camellias, will appreciate it if you pour iron residues around them. I usually pour the remains of iron modifier solutions around my blueberry bushes.
Copper sulphate can be used as a modifier in the same way as ferrous sulphate. You can also make your own copper water by soaking lengths of copper piping in a solution of 1 part water to 2 parts vinegar until the liquid looks blue/green in colour. Proceed as described above for iron water. Remember that copper is poisonous so handle with care.