Okay my little, noncontributory countrymenwomen, gather around and clean your ears out.
I found a place in Christchurch that sells natural dyes! Small amounts at exorbitant prices but great for experiments. They sell both extracts and raw materials.
Now after mucking around with them, I found out they worked pretty well. I was whole dyeing tee shirts, hoodies and sweatshirts.
After a bit more hunting on the net I have found Botanical Colors! "oh là là" I hear you squeak.
This is where I am buying my bulk dyestuffs from! Fantastic, Kathy from Botanical Colors will totally look after you. Seriously, she has a wealth of knowledge and eager to help. I've put my order in and can't wait for them to arrive.