Weld (Reseda luteola) is an incredibly popular dye plant. Growing wildly in Europe, it is an easy plant to grow, maintain and harvest. Yielding a yellow colour:

"Weld for yellows and greens was the equivalent of dyer's madder for red: an indispensable dyestuff used by all the early civilisations of Europe and the Mediterranean." (Cardon, 2007, 168)

Above are some images from my trial of using weld extract from Wild Colours. On the sustainable production of the extract, their website states:

"It is produced using processes that respect the environment and comply with organic textile certifications. Our Weld dye extract is an approved dyestuff for the Global Organic Textile Standard (GOTS 4.0)" (2017, online)

I used the extract as I have not had the time to grow and harvest my own weld (it's also winter so foraging is difficult!), but going forwards I plan to grow some in my garden. along with other native dye plants such as woad and madder. Cardon's Natural Dyes has thorough notes on cultivation. The potential to produce such a vivid yellow with a common native plant is very exciting! 

Burns, R. (2017)  Weld 4 . (Own Collection)

Burns, R. (2017) Weld 4. (Own Collection)