The Handbook to the Flower Garden and Greenhouse by George Glenny, F.H.S is today’s PDF download.
While a book on flower gardens is not much interest to a doomsday prepper, the skills are transferable, and a nice flower garden in the neighborhood shows normalcy and is probably and easier sell with the spouse than saying you want to build a greenhouse to grow food for the apocalypse.
The following is from the Author:
The Handbook to the Flower Garden and Greenhouse
The third edition of this work presented such a total change from the first two that it could hardly be recognized, and at the eleventh hour I had merely an opportunity of disclaiming all the alterations.
In revising the work for the fourth edition I have removed nearly eighty pages which were taken from, and belonged to, botanical dictionaries, and have restored much that had been taken away to make room for matter not original.
I have not disturbed the alphabetical arrangement, although I have expunged the names of many genera and species of no earthly use to the florist ; for I consider the work belongs to the popular flowers, and not to botanical collections, besides which I have a thorough deep-rooted aversion to copying from others.
I trust I have improved even upon the original edition, and at least have the satisfaction of knowing it is all my own.