All my tomatoes have black spots?!?

So I just started my own small garden this year. It's ontop of where we used to have our chicken run, so there are alot of volunteer tomatoes from the scraps we fed our chickens. I have about 3 tomato plants (which are all massive) and an eggplant. The eggplant is doing well as are the volunteers, and the one tomato I planted. 

However tomatos on the one I planted (I believe it was Better Boy or Big Boy) all have large black/brown bruises/spots on the bottom. I tried eating one, and discovered it goes a part way into the tomato as well. How can I combat this? Especially naturally or organically. Is it to late to do anything? 

Thanks! 

canucksgirl5 years ago
It sounds like "Blossom End Rot"... Here's some info and remedy. (Link didn't work). :-)

http://en.wikipedia.org/wiki/Calcium_deficiency_(plant_disorder)
Re-design5 years ago
There are a lot of things that can cause this, bugs, funguses, bacterias, lack of certain minerals etc. It might be a good idea to take a couple of the damaged ones to a garden center for some pro help.