My plant-knowledgeable and extremely generous Katoomba friends harvested some Indigofera Australis for me recently, and I brought it home gleefully to experiment. They have regular access to a place where Indigofera Australis is growing plentifully and where it is native. I had one previous opportunity to try dyeing with this plant and it was fascinating but completely unsuccessful. So, it was exciting to have another chance. There were 112g leaves in my parcel once I stripped them from their branches. They had been kept cool or refrigerated in the 7-10 days since they had been picked–fresh but not really fresh. I decided to try two different methods.
The first is a cold process suitable for protein fibres only, using vinegar. I have found it described online as a way to process Japanese Indigo to achieve turquoise by Dorothea Fischer and in a booklet by Helen Melville. Japanese Indigo is a prohibited import and not available in Australia (no matter my feelings on the subject of Japanese Indigo as a dyestuff, this country does not need more weeds). It does seem logical that this method should work on other indigo bearing species, even if Austral Indigo bears a lower proportion of indigo! However, using the leaves fresh is a key element and my leaves weren’t as fresh as possible.
Since my last effort, my Dad bought me a cheap secondhand blender (which I planned to use for papermaking). It made pulping the leaves so easy I didn’t even try cutting them up manually…
The water immediately went a vivid green, and so did the froth on top.
I began with a sample card and a small quantity of silk thread, and gave them a few dips before bed time, then left them in overnight and re-dipped in the morning. Here they are before being further re-dipped, with every fibre on my test card except cotton one shade of turquoise or another:
I also tried dyeing some wool, but even after a lot of dips my little skein is barely blue. End yield: 2 lengths of blue silk thread, three lengths of grey-green-blue silk thread and some off-white-in-the-direction-of-blue-merino. Clearly, as I had heard, Indigofera Australis is a low yielding source of indigo. But this method was brilliantly simple, easy and non toxic. I will happily try it again when my plants are a little bigger.