You're watching a tomato ripen on the vine and your mouth is watering at the thought of that tomato finally ripening. Then you go to pick your tomato from the vine and notice that it is cracked! What went wrong? Tomatoes will split and crack as they grow because of fluctuations in the soil moisture. Uneven watering, especially in container gardens, is the cause of tomato splitting and cracking. This will happen if you forget to water your tomato for a few days and try to make up for it by giving the plant a lot of water at one time. Or, if you skip the watering schedule because a recent rain has given you the impression that your plants are fully watered. The tomato pulp expands faster than the skin grows. It is a common tomato problem and happens to the best of them.
This is what happened to my "Great White" tomato pictured above. I thought it was getting enough water between recent rain fall and my normal watering schedule. Then we got a heavy rain this week and overnight the tomato cracked. It looks ugly but the tomato is still edible. I wish I had listened to that little voice inside my head that told me to pick the tomato this past weekend and let it continue to ripen on the windowsill. Now I have a tomato with more cracks than a room full of plumbers.
Uneven watering is also the cause of blossom-end rot. I'm growing these tomatoes on my porch garden. See the link for a list of plants I'm growing in that small space.