- Exploratorium: Science Of Gardening
- Features articles and videos on several topics, including gardening with nature, carnivorous plants, soils, fruits, and vegetables, propagation, and plant reproduction.
- Garden Terms
- Gardening dictionary with brief definitions of a large number of terms, optionally arranged by category.
- Let's Go Gardening
- General gardening site, with versions geared towards US and UK gardeners. Tips and articles, informational resources, links to events, societies, and public gardens, and a forum.
- Ohio State University PlantFacts
- Collection of horticultural resources, including a search engine drawing from U.S. university factsheets, plant image database, how-to videos, illustrated FAQs, and glossary.
- P. Allen Smith Garden Home
- TV host, writer, and professional gardener, P. Allen Smith provides tips on a variety of gardening topics, along with his biography, recipes, and instructional videos.
- The Garden Helper
- Offers basic information, seasonal tips and task lists, plant indexes by common and botanical names, and advice on soil, fertilizers, pest, and weeds.