I’m actually happy to read this, since I think it’s taking historicism to a rather ridiculous level (yes, I know, this from someone who wants to make a shirt from seed) to insist on woad rather than indigo for blue dyeing.  But I’m relieved to have an answer to people who say ‘but indigo is a post-period dye’ – which is a mis-statement on many levels – indigofera is a post-Period DYEPLANT, the dye indigo is the same from woad and indigofera, it just occurs in more density in the latter.  It also occurs in other plants.  The job of the historical dyer is to alter their work accordingly.

But to today’s point:  From SCA_Natural Dyes:

So they are right to fear madder and woad, both of which scatter quickly in
their own way. Madder is just a nuisance, and can be grown in a metal tub
off the ground. But woad not only scatters seed very quickly, but it raids
the soil of all nitrates and makes it difficult to get the soil back in any
condition again. That’s why woad is banned in most of the US, and is
systematically destroyed in the northwest states.

I’m sorry, but the vanity of our research game is not worth screwing up the natural environment that supports us.  I will not be trying to grow any woad, and I won’t buy any.  I may buy madder, but I don’t think I’ll be growing it either.

And that apparently is the defining edge of my dedication.  [Whew!]  I was starting to fear this business was going to expand indefinitely in ALL directions.  That’s frightening even to ME.