How to Raise, Germinate and Harvest Certain Plants

We are interested in several herbs; but are scared to invest a lot of money until we are sure of how to plant and harvest and process them. The ones we are interested in are: astragalus; catnip; German chamomile; chia; pleurisy root; pumpkin Styrian; senega, Chinese; and the mimosa Tree.

You are wise to be careful when considering new crops to grow. Not every herb will work in every situation. That's not just because the production is different for each herb; it's also because the market and the marketing is different for each herb. That's why we advise growers to start with small test plots for new herbs. Test plots allow growers to work out and refine the production details, and at the same time growers can produce samples needed when talking to buyers.
Your list of herbs is a mixed bag of plant types with different growing and processing needs. There is no single source that covers all of these herbs in the kind of detail you are looking for. The book, Herbal Harvest (see www.richters.com/Web_store/web_store.cgi?product=XB5060) has good information on about half of the herbs. There is also good information in the grower zone section of our website for some of these (astragalusis listed as "Milkvetch, Chinese").
Commercial cultivation information published in English for chia, pleurisy root, Chinese senega and mimosa tree is limited. Some basic information is available in the Plants for a Future database (https://www.ibiblio.org/pfaf/D_search.html). You will have to develop your own methods for growing and processing these crops. When developing methodologies for commercial production of new crops it is often possible adapt the methods of similar crops.

Also, what is the availability of dong quai seed? If they are, again how do we grow and use it. Robert is asking for as much detailed information as possible, as we are very novice in this area.

We had some success with dong quai seeds in the 1990s but haven't had any luck since. The seed is short-lived and our sources do not seem to be able to get seed to us quickly after harvest. In China attention to seed quality is still pretty poor and acquiring seeds there is a real crap shoot. We keep looking for viable seeds and when we get some we will get them up on our website.