Any one having blossom end rot (Zukes and tomatoes) in a smart pot? I put bone meal in the mix so I am thinking its a watering problem--?(They are 15 gal. generally 1 tomato and 2 zucchini per pot)
Well, since bone meal can take months and months before it is available to the plant,
I'd guess that your mix is lacking useable Calcium. That's one of the major drawbacks
to using organics in containers.
Of course, if your soil is staying too wet, then that could be impairing Calcium uptake.