Great idea I read online:

Funding Next Year's Garden

I love to vegetable garden. I always have more than I can use.
I take my produce into the office and have a "Take Some and
Leave a Quarter" cup next to them. I use this to buy my plants
for next year. They get fresh produce, and I haven't had to
pay for new plants in three years! I even take requests.
Christian F. in Olathe, KS