I remember in the 70's doing tie-dye in a pot on the stove, using Rit dyes I think...or it could have been cool-aid. But I had forgotten the process until a bunch of us from the Desert Sage Fibre Guild got together during Studio week here in Oliver to learn the process of natural dyeing. We used silk scarves. I had Marigold flowers in a self contained kit from helenkrayenhoff.com These are great little starter kits if you know nothing and are just starting out. You just have to find a cheap steel pot and spoon - the thrift shop is a good resource. Don't use your good spaghetti pot whatever you do. And don't use the dye pot accidentally for Spaghetti.
I discovered dyeing is a meditative process. First the Alum is heated and the fabric - the innocent silk scarf in this case - is simmered for half an hour. Then it is taken out of the hot water and a new pot is set to simmer with the Marigold flowers in it. I guess you could put the flowers in a cheese cloth twist, but, being new, I dumped them into the water. The dried flowers had to simmer for a while so the water would be coloured. I have to say, brown/yellow isn't my favourite colour - but, well, you have to start somewhere don't you.
So... while the Marigolds were stewing, I folded the scarf like an origami and secured it with elastics and popsicle sticks and had a cup of tea.. Just for extra fun, I pinned the corners with clothes pins too - resist dyeing they call it. I remember that from the tie dye days but this is a tad more sophisticated I think.
The goo in the pot didn't look like much but in went the pinned scarf and simmer I did - and the final product was worth it I think.
So now, I'm looking at the garden in an entirely different light - and plucking pink and purple flowers to dry. And looking at my yarn stash to see if there is something in there I can experiment with.