View Federal and state noxious weed lists, an invasive plant list, or an introduced plant list, each with links to more information.
Archives: Recommended Websites
How To Identify and Control Noninfectious Diseases of Trees
An article by the Northeastern Area of the US Forest Service that describes diseases caused by non-living agents, such as winter damage, sun scald and herbicide damage.
Frost Chart for the United States
First and last average frost dates for major American and Canadian cities, plus the number of days in the average growing season for each city.
Frost Dates for Washington
First and last average frost dates for 23 major Washington state cities from Aberdeen to Yakima.
Ecologically Sound Lawn Care for the Pacific Northwest
This report published by Seattle’s Public Utilities summarizes research and recommendations from both horticulture scientists and turf professionals.
Nine Keys to Disease Prevention
By Brooklyn Botanic Garden. A common-sense approach to plant disease prevention
Natural Pesticides
By Brooklyn Botanic Garden. The article covers microbial pesticides, horticultural oils, insecticidal soaps, alcohol, and botanical insecticides.
Cornell Composting
Links and articles, including resources for teachers.
American Conifer Society
This site includes a conifer database with photos, events calendar and a forum for questions and discussion.
Conversion Tables, Formulas and Suggested Guidelines for Horticultural Use
Samples tables include equivalents for liquid measure, dry measure and weight, metric system and fertilizer conversions, formulas for fertilizer calculations, and plant spacing guides.