About thirty-five years ago, pre-internet, I got the three volume set of Liberty Hyde Bailey's The Standard Cyclopedia of Horticulture. It never let me down when I needed it.

That set, along with Wyman's Garden Encyclopedia, covered 99% of what I needed to know. (Wyman's is Massachusetts based which worked for me when it came to recommended varieties.) LH Bailey was a writing machine...and what he wrote was good. Google him and 6 pages of returns are his works...and then you start getting the returns where he was writing in a journal or magazine or with someone else.

I have been spoiled by the internet. I don't get up and go to my own library! If I had I would have posted this already :-) Once I remembered my old friend (the book, not Bailey) I looked it up online and here is the entry for china asters. The link is below to the whole volume if you like. He includes such great information - history, opinion and fact. Here is part of the preface to Volume I. You can start to read Volume I and find yourself sucked into a fantastic world of people who really know their plants. Specialists contribute to entries in the Cyclopedia.