So I wasn't surprised when Allen Lacy, whose garden books line my shelves, emailed me recently to mention casually that he and his wife and tireless sidekick, Hella, had planted 100 or so salvias at the Linwood Arboretum in Linwood, N.
For example, a study from 2008 showed that walking through an arboretum boosted people's performance on memory tests.
