During winter months, I tend to dye yarns mostly with acid based dyes because they are quick reacting and simple to work with. Now that it is spring and the sun is shining, I can again do some dye work outside so work more with natural plant dyes. Natural dye baths and mordants require much more time to prepare so I leave dye pots outside to steep and do their thing.
The use of urine in washing wool & dyeing fleece or yarns
How To Mordant Cotton and Linen Yarns recipe