I have a whole row of tomatoes: brandywine, striped cavern, prudence purple, roman paste, san marzano....

i've picked a few good ones (only plums so far) but also a LOT of fruit with what I think is blossom rot. They have black, mushy bases (end of fruit opposite picking end) and look almost like a fungus. I chuck them far down the hill but am annoyed by how many they are.

I keep a mainly organic garden with lots of comost- obviously we have had lots of heavy rain this year... any suggestions?