There are lots of good resources for gardening for biodiversity and native plants in general on the web:
The USDA’s plant database is most extensive source of information about all plants in the U.S., and the starting point for almost all of my plant searches. For many plants, it offers maps showing both its current range, and its native range. The site also offers links to other information sources for each plants.
The Lady Bird Johnson Wildflower Center (with the great URL, www.wildflower.org) lists thousands of native plants and lets you search for plants that are suitable for your state and your site conditions. The site also offers suggestions for native alternatives to common non-native plants. Mr. Smarty Plants also answers your garden questions, and the database of related answers is a treasure trove of useful advice.
The New England Wildflower Society offers useful information and articles for native gardeners anywhere, and for eastern Massachusetts gardeners, it is a fantastic source of native plants for the garden. (They also have a native plant nursery in western Massachusetts.)
Grow Native Massachusetts: This is a really local (for me) organization focused on growing native plants and gardening for biodiversity in Massachusetts, based in Cambridge, MA.
The Connecticut Botanical Society offers suggestions about native plants for gardens, as well as having photos and information about a large number of native plants in Connecticut.
Doug Tallamy’s site about his book, Bringing Nature Home, offers lists of plants by the number of insect species they support in the mid-Atlantic U.S. region.
For New Englanders, the Weston Nurseries plant search is a great resource. Their extensive collections can be searched for plants native to New England or eastern U.S., and they provide detailed information needed for gardeners (e.g., height after 5 years, height at maturity). They are an especially great resource for shrubs and trees, and the site gives you a good indication of whether a native plant or cultivar is likely to be available commercially, because if they don’t have it, it’s not going to be easy to find. Use the broadest search term possible, because it will only return results for exact matches.
The American Beauties site provides information about native flowers and perennials for gardeners, and offers plant lists and garden plans for butterflies, birds, sunny and dry shade conditions, that can then be refined by region. The site is sponsored by the National Wildlife Federation, and is tied in with a branded American Beauties native plants program at commercial nurseries in the northeast.
The University of Michigan has a Native American Ethnobotany database that provides infomraiton about how plants were/are used by Native American peoples for food, drugs, dyes and fibers.
These other plant databases provide extensive information on mostly regional, mostly native plants:
- The University of Connecticut Plant Database by Mark H. Brand
- The Plant Finder at the Kemper Center for Home Gardening sponsored by the Missouri Botanical Garden
- Paghat’s Garden – not really a database, but this website that tracks an individual home’s gardens in the Puget Sound area of Washington state offers a tremendous wealth of plant information
- The University of Tennessee’s Herbarium Vascular Plants database provides species information and photos (and locations within Tennessee, naturally)
- The Robert W. Freckmann Herbarium at the University of Wisconsin lets users search for plant information (and Wisconsin locations)
- Dave’s Garden – also not really a database. This is an extensive gardening community, with both free and paid subscription areas. The vast majority of the site is focused on traditional gardening and it can be hard to figure out what’s native or not, but it is a good resource to see real-life experience with plants.