Although I mainly use synthetic dyes for my weaving yarn and spinning fibre, I have long liked the look of yarns that are naturally dyed. I don't think it is a method for me when making items to sell. The weaving takes long enough!
Since we have a greenhouse that is used mainly to store garden 'thing' I have taken to use it for solar dyeing a quick, if less predictable, way of natural dyeing.
This picture is some yarn that I removed from a jar today. The large skein was in a solar jar with madder at the bottom and onion skins at the top, hence the two colours on the yarn. The small skein has been dyed with saffron. I have left the wool that was with it in the jar. It was much paler, but there was still dye colour in the liquid, so it may get a deeper shade.
The green skein was dyed with honesty and primula flowers, the centre skein and silk scarf with eucalyptus bark.