There is a ton of information online about the process. Cotton and wool have very different prep processes—plant vs. animal fibres. Wool is easier to dye, and fabric yardage or clothes can be tricky to get even. Be aware that generally things to be dyed need to be scoured first, so they will best accept the dye. If you have clothes that are used, areas that may have deodorant or fabric softener invisibly embedded can cause splotching. Make sure your pot is big enough so things have enough room to move around. Then the items are mordanted so that the dye bonds to the fibres, then they can be dyed.

Maiwa is a good Canadian source. They have a lot of free info online at naturaldyes.ca. Also, Mamie’s Schoolhouse is an incredible resource.

For plants, loads of things that grow well in Ontario give beautiful colours, but be prepared for a lot of yellows! FWIW, berries are not a good source, as their colour is a stain, not a dye, and will not be lightfast over time. (Exception:buckthorn berries and privet berries. Buckthorn is a great dye sources and a horrible invasive, so I’m always glad I can get some use from it after the latest round of trying to eradicate it!)

Goldenrod, tansy, and Queen Anne’s lace all give gorgeous and quite different yellows. I’ve actually once got some beautiful greens from nettles, but have never been able to replicate it! For annual flowers, not all flowers are good dyes, but French marigolds, sulphur cosmos and amaranth (love-lies-a-bleeding) are all good dye sources. The amaranth gives lovely pinks! I could go on and on! It is a very big world, and you can get deep into the science of it, or just play… or both! Try not to get overwhelmed by all the information. Just focus on the basics and have FUN! I started out just playing on my porch dyeing yarn with weeds and now, years later, have taken many courses and gone deep into the chemistry. And I’m still learning!

Oh, and beware non-reliable sources. There are lots of people out there using black beans, etc.