I like the Hemenway book. For one thing it tells you have to plant under a walnut tree and its probably worth $9 just for that information.
Also it will take you square into the hot debate about "native plants".
Some native plant people take exception to the strategy of using invasives as nitrogen fixers. Plant native they say. But what is native?
When? Plants that grew in the Pleistocene probably will not be adaptive to extant environments, today. Its an interesting argument, I think. Hope you enjoy this American version of permaculture book!
