If you are planning on relying on herbs in a post collapse, keep in mind that most medicinal herbs have a shelf life of about a year. Given that there is not a huge demand outside of a minority community, I would not expect shipments to start showing up at the ports for a few years after an event. You would need to have a plan that involves herbs that can be grown locally.
The good news is that a lot of herbs found in TCM Materia Medica can or already do grow in the North East (Mint, Rhubarb, Dandelion, Peony). Many more can be grown in other areas of north America (Ephedra, Ginseng, Safflower), so it’s possible that some sort of trade pattern would eventually establish. Some of the harder things to procure, will be tree resins like frankincense and myrrh, as these products tend to come from unfriendly places. I would bet that there are suitable substitutions to found in North America, but they have yet to be researched and categorized into TCM text.
The bad news, is that using them effectively is going to require a bit of study. The good news (about the bad news) is that the Chinese have been compiling data for at least the last 2000 years, and they were working off data compiled by Indians for a 1000 or so years before that. In this regard, we stand on the shoulders of giants. If anyone is up for it, the underlying theories are accessible to people of normal intelligence.
