Answer: There are lots and lots of books available at your local library or book store. My favorites include:
Rodale's Illustrated Encyclopedia of Perennials: 10th Anniversary Revised and Expanded Edition by Ellen Phillips and C. Colston Burrell (Paperback - May 5, 2004.
Encyclopedia of Perennials (American Horticultural Society) by Graham Rice and Kurt Bluemel (Hardcover - Sep 18, 2006).
Perennial Combinations: Stunning Combinations That Make Your Garden Look Fantastic Right from the Start (Rodale Garden Book) by C. Colston Burrell (Paperback - Feb 19, 2008).
Your local cooperative extension office will have publications to assist you and can probably identify the plants if you take the flowers in.
Or, you can cruise the local nurseries and garden centers, flowers in hand to compare what you have with what's in bloom.
I'm sure you'll eventually put a name to every plant in your garden. Enjoy!
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