Or you could.. You know.. Just plant the things. Dude, you're growing French tarragon because you like eating it. If you were setting a commercial setup, then I might understand this desire or need to go into such ridiculous amounts of detail. But you are literally putting some tarragon in a container. https://www.environment.sa.gov.au/goodliving/posts/2019/05/guide-to-composting It's really not that hard. Nor does it have to be that complicated. Or you could, you know, just plant your French tarragon and see if it grows. Here is a super simple guide: https://www.finegardening.com/article/french-tarragon Good luck!