Beginner Gardening: What is happening to my tomatoes?, 0 by bklynbeginner

bklynbeginner wrote:
Hi, I am on my first year of starting a container garden on my deck in Brooklyn. I have a few different kinds of tomato plants in large pots and they seem to be healthy. Now that I have some unripe tomatoes coming in and growing, I have noticed that on a few of the plants (notably, the "Big Boy" variety as well as some smaller tomatoes I am not sure of the name, but they look like grape tomatoes), the bottom of the tomato is turning blackish, even though the rest of the tomato, and the plant, looks healthy. I have attached a picture. Is anyone familiar with this problem and know what I can do about it? I'd appreciate any help, I want some healthy tomatoes! Thanks :)