PLANT CATALOGS & DATABASES
- United States Department of Agriculture Plants Database
- Plant Selection Program, Sustainable Urban Landscape Information Series, University of Minnesota
- Perennial Resources, design & encyclopedia
- Bailey Nurseries
- Easy Elegance Roses
- Endless Summer Hydrangeas
- Monrovia
- Terra Nova Nurseries Perennials
- Walters Gardens, Inc. Perennial Library
- Houseplant care database
- University of Minnesota Plant Info, collection of plant databases