Find answers to your most challenging gardening and horticultural questions.
State-based experts for all of your gardening needs
Cooperative Extension programs, also called Local Extensions, Extension Offices, are one of the most important—yet often overlooked—gardening and horticultural resources available to residents across the United States. Founded more than a century ago through partnerships between the U.S. Department of Agriculture (USDA) and land-grant universities, these programs bring research-based knowledge from the classroom directly into communities.
Every state has an extension system tied to its land-grant university. Through local offices, often at the county or regional level, they provide free or low-cost services such as:
- Gardening and agriculture advice (soil testing, pest and disease ID, and plant care)
- 4-H youth development programs
- Nutrition, food safety, and health education
- Sustainability and environmental stewardship resources
- Community outreach and volunteer opportunities
Master Gardener Programs
One of the best-known programs is the Master Gardener Program, which trains volunteers to become ambassadors of horticultural knowledge in their communities. Participants receive classroom instruction, hands-on training, and commit to volunteer service hours, ensuring research-based gardening knowledge reaches a broad public audience.
Extension Programs by State
Connecticut (UConn Extension)
- Websites:
- Contact: extension@uconn.edu, (860) 486-3581
- Services: Ask Extension Q&A, soil testing, workshops, nutrition programs, 4-H, and sustainable landscaping.
- Master Gardener Program: 16-week core classes + 100 volunteer hours; applications for 2026 open until October 17, 2025.
Massachusetts (MMGA & Cape Cod Cooperative Extension)
- Websites:
- Unique Structure: Unlike most states, UMass Extension does not manage a Master Gardener program. Instead, independent associations run them.
- Services: Clinics, soil testing, speakers bureau, hotline, community gardens.
- Master Gardener Programs: MMGA certification; Cape Cod training and clinics.
Rhode Island (URI Cooperative Extension)
- Websites:
- Contact: gardener@uri.edu, (401) 874-4836 (Mar–Oct, Mon–Thu, 9 am–2 pm)
- Services: Gardening & Environmental Hotline, soil testing, plant clinics, outreach events.
- Master Gardener Program: Core Training Course (14 weeks), volunteer service, hotline, and event support.
Vermont (UVM Extension)
- Websites:
- Contact: master.gardener@uvm.edu, 1-800-639-2230
- Services: Plant problem diagnostics, soil health advice, helpline.
- Master Gardener Program: 16-week online course; certification requires 40 volunteer hours.
New Hampshire (UNH Extension)
- Websites:
- Contact: answers@unh.edu, (877) 398-4769
- Services: Yard & Garden Infoline, soil testing, workshops.
- Master Gardener Program: Hybrid training (online + in-person labs), volunteer service.
Maine (UMaine Cooperative Extension)
- Websites:
- Contact: extension.mastergardeners@maine.edu, (207) 581-3188
- Services: Q&A, soil testing, community partnerships, demonstration gardens.
- Master Gardener Program: 40-hour training + internship, online coursework, annual volunteer service.
New York (Cornell Cooperative Extension)
- Websites:
- Services: County-based gardening help lines, plant clinics, youth and nutrition education, and agricultural programs.
- Master Gardener Program: Volunteer training offered county by county; public Q&A and educational outreach.
Local extension programs are built for you
Northeast Cooperative Extension programs are deeply tied to the region’s agricultural history while serving today’s gardeners, farmers, and communities. Whether you want to diagnose a sick tomato plant, understand ways to treat invasive plants, help pollinators, take part in sustainable food initiatives, or train as a Master Gardener, these programs provide a wealth of science-based knowledge and resources for everyone.
