Here are some websites that regularly offer listing of garden events in the area.
American Horticultural Society Events & Programs
DUG DC Urban Gardeners Network Events
Pegplant – Local Monthly Events
United States National Arboretum Calendar of Events & Programs
What’s Happening at Smithsonian Gardens Exhibits and Events
I’m glad to find NVMG! I found a “Plant One Million Trees” for Pennsylvania. Do we have a similar program? I recently planted a Red Bud, 2 Schip Jacks, and a hydrangea. I’d like my plants to count towards reforesting our area.