You can help by going here and donating what you can, and read on for more info from the Marketplace folks:
The Columbia Heights farmers market has already surpassed its goal of raising $2,500 to give 50 needy families $50 each to spend at the market before Thanksgiving. Based on the success, they're now shooting to raise $5,000 with less than 2 weeks to go.
Every year the market matches federal food assistance dollars 2-to-1 to help low-income residents access the fresh local food at the market. That program has been a huge success, so much so that the market runs out of cash every year well before the end of the season. The Farmers Market Thanksgiving campaign came about to extend that program at a time of year when people are celebrating food and family.
An added bonus: the money goes to the local producers and farmers that make the market so special.
It's not too late to help out. Check out their fund raising page here