Sometimes no matter how careful we are with our dyeing with plants, the results are still slightly patchy. Rather than getting too frustrated in these situations, it can be more helpful to try to accept that it's a natural process using natural materials and embrace the imperfect beauty.
It's very difficult to dye a large piece of fabric or clothing entirely evenly and sometimes the effort spent trying just isn't worth it (in my opinion anyway). Why are we trying to create a colour so uniform? Are we trying to replicate something that synthetic dyes do?
Quite often I prefer to dye with simple tie dye/shibori techniques to have more control over the final result. For example, scrunch dyeing can be a way to accentuate the patchy areas that dyeing can produce. So instead of random streaks that may appear as part of the process, you can control these darker areas and make them into a feature. I'll show you how to do this in a future blog post.
If you're dyeing curtains, scrunch dyeing can be a useful method to use. Imagine trying to dye two curtains exactly the same colour without any patchiness? I would feel quite stressed at the thought of attempting this, and it's a question that I get often. You could buy a pair of enormous dye pots and stand there stirring for a few hours (you'd need two pots so you could measure the dye and get them the same colour), or you could scrunch or fold the fabric and dye in one dye pot. When asked about dyeing curtains, my suggestion is usually to avoid aiming for uniform colours in the first place. It's totally do-able for items of clothing, but it's virtually impossible for enormous pieces of fabric without industrial-sized pots.
I hope that this blog post has some helpful tips. Do you have any other questions? I'd be happy to try to answer them, or even turn your question into a blog post and answer it in more detail.