+1 on Charlton Orchards. I have been buying produce from them at the Bedford farmer's market all summer, even though there are at least 5 farms within 5 miles of my house. They sell a lot of different things.
I know that there is a farmer in Lincoln who allows you to buy "shares" of his beef and chicken for the year. I am not sure if it is organic, but there must be other farmers in MA who do this.