I've been following the Back Yard Farmer for two seasons now. I love it and have learned a lot. Along with the numerous mailed in questions, they do little segments on special, seasonally relavent topics. All the panelists are Unv of Neb proffessors, so it's really good, evidence based advice. Since it's video, you actually get to see a lot of the weeds, rots & spots, and plants they are talking about. One of the best podcasts on gardening available.