I’ve spent the last seven years wandering the world, teaching people from all walks of life how to use plants to dye cloth. I didn’t carry dye materials between countries because most plants yield some kind of colour and it’s better to investigate local species than import dyes, especially when producing some dyes may compromise their source environment. For example, logwood (Haematoxylum campechianum, a Mexican and Central American species) yields exquisite purple, blue, black and brown dyes; however, the heartwood is used and harvesting it kills the trees of this increasingly rare genus. The best dyes come from older trees and even if seedlings are planted to replace those that are felled, it takes at least 20 years for those to mature.
On the other hand, respectable shades of purple and black can be made by boiling the leaves of the Australian species Corymbia citriodora (lemon-scented gum) in an old iron pot. Boiling the leaves in a non-reactive pot, such as stainless steel or enamel, yields a lovely chocolate brown. It makes much more sense to me to use the leaves of a plant that is relatively common, and a good stiff breeze will deliver abundant dye material to the ground at your feet.
I always keep an eye out for eucalypts when I travel. Although mostly native to Australia they’ve been introduced around the world, and are often regarded as weedy. Eucalypts are my favourite dye plants, though still not taken seriously by traditional experts. This may be because – unlike plants like logwood, woad Isatis tinctoria, weld Reseda luteola, madder Rubia tinctorum and indigo Indigofera tinctoria – there isn’t a long history of use.
Australia’s indigenous population didn’t have access to metal vessels and couldn’t boil the leaves to release the intense red colours. Nor did they keep sheep, whose miracle fibre – wool – is the one that eucalypts dye best. Indigenous Australians ground minerals and roots as their source of colour; usually applied as a paste or stain. Dyeing basketry fibre in the Northern Territory using Morinda citrifolia (Indian mulberry) root, with ash as a mordant (to set the dye) to make red, is comparatively recent, dating from the introduction of metal vessels that could be heated over fire.
Eucalypts are also very interesting in that they can indicate pH and salinity in water supplies. If the water is alkaline the dyes obtained will tend to be somewhat muddy; neutral to acid water supplies yield the best and brightest colours. The presence of salt is indicated when the dye cools if a cloudy suspension forms near the base of the dye-pot.
As well as seeking out my favourite compatriot plants when travelling, I also get hold of the local weed list, as plants that have come to be regarded as weedy were often introduced by settlers who valued them. And having the list in my pocket when I’m out harvesting plant matter gives me justification if I’m challenged. For example, in some states of the USA the traditional dye-pot favourites woad and weld are listed as noxious weeds. People are discouraged from planting them and encouraged to remove them from the environment where possible. Woad is a splendid source of sky blue, while weld yields a rich gold and can be used either with copper or as an overdye for woad to make a rich and lovely green.
Another, common weed is St John’s wort (Hypericum perforatum). Originally native to Europe and the temperate regions of Asia, as a traditional medicinal herb it would have been carried by settlers. Its seeds dispersed in water, mud and agricultural produce, and on fur and in the guts of animals. It has spread far and wide and can now be found in golden drifts along roadsides and in paddocks in rural Australia where it is often listed as noxious.
Traditionally St John’s wort has been used to treat depression and anxiety. It also has toxic properties; – it is poisonous to grazing livestock. However, St John’s wort is an extraordinary dye plant. When simmered in water in a non-reactive pot it yields a ruby-coloured liquid that dyes dark maroon reds on protein fibres, golden yellows on cellulose fibres and, if a little alum is added to the brew as mordant, turns a lurid lime green able to dye most fibres including synthetics. An ecoprint (a contact print on cloth in the presence of heat and moisture) reveals the red dye parts as tiny dots of colour that cluster thickly about the stamens of the plant, less abundantly on the petals and gradually diminish further down the stalk. The red pigment, hypericin, is fluorescent and allegedly visible to animals at night. Sadly my eyes are not sufficiently receptive to this magic. Given St John’s wort’s usefulness as a dye, it is surprising that textile practitioners are not wandering Australian roadsides in droves in the peak flowering times – November and December – for this ubiquitous plant.
Inspired by the late North American dyer Fred Gerber, I conducted a series of experiments with the St John’s Wort dye liquid to see how it might be affected by mordants. Mr Gerber recommended making the dye liquid and then placing samples in small white ceramic or porcelain vessels. Keeping one of these as a control, he would add very small amounts of traditional metallic salts to assess which one(s) he might most usefully add to his dye-pot.
I consider iron, chrome, tin and copper salts far too dangerous to play with and have derived safer alternatives including: scrap metals from friends’ sheds and workshops; bottle-caps found crushed in hotel parking lots; aluminium foil from chocolate wrappers (Swiss brands use foil of exceptionally good quality); and dog-spikes from the side of the railway. I sort the metals into glass jars and then add a range of liquids such as vinegar, seawater, that sour stuff left over when the pickle jar has been eaten out, urine and bore water. Saving vegetable and fruit peels, and fermenting them in a bucket of water produces an economical vinegar equivalent (which can also be used to neutralise alkaline water in a eucalypt dye-bath). I then dish out dye solution into a range of white ceramic or porcelain containers (you can find them at op shops), add small amounts of the homemade mordants and watch for colour changes before deciding which one to add to the main bath. The rejected mixtures are splendid for dyeing thread.
The most important thing about dyeing with plants is ensuring that you can identify the plant material correctly before collecting it. You need to know whether a plant is: worth collecting, and when and what material to collect; legal to collect; safe or toxic; and how to protect yourself when collecting it. When you are sure of the plant you will also be able to research information about how to use it.
Each bioregion has a different range of plants and it is the responsibility of dyers to learn about them. If that’s too hard for you there’s always the fallback option … using green waste from the local florist. But that’s a story for another day.
India Flint is the author of Eco colour (2008, Murdoch Books), Second skin (2011, Murdoch Books) and Stuff, steep + store (2013, Blurb). Her work is represented in museum collections around the world, and her garments are sold through boutiques in Hollywood and Boston. See www.indiaflint.com and http://prophet-of-bloom.blogspot.com.au/