Harford County Master Gardeners are trained volunteers of the University of Maryland Extension, educating County residents about safe, effective and sustainable horticultural practices. MG's do this in a multitude of ways, including partnering with these local organizations:
| Anita Leight Estuary Center | Bel Air Farmers Market |
| Brightview Senior Living Community | Eden Mill Nature Center |
| Harford County Public Libraries | Harford Family House |
| Harford Glen Environmental Education Center | Havre de Grace Farmers Market |
| Havre de Grace Heirloom Victory Garden |
Liriodendron Mansion |
| Ladew Topiary Gardens | Mason Dixon Community Services |