A seed swap is an event where—see if you can follow this intricate description—people swap seeds. That is to say, gardeners bring excess or unusual seeds to a central location and trade them for others—perhaps to obtain new heirloom plants, to try new things, or just for garden-variety (see what I did there?) diversity. I’m sorry to say that I don’t have anywhere to put a garden, but if I did, I’m sure I’d find seed swaps delightful. Washington Gardener Magazine started National Seed Swap Day in 2006, and it has been held the last Saturday in January ever since.