What is wrong with my Big Boy tomatoes?

Question

We have 3 Big Boy tomatoes and 3 Mountain Magic tomatoes. Before I begin there are a couple of things you need to know: 1) We just found out our soil is nitrogen depleted (not from a home test) and 2)The tomatoes are in 5 gallon buckets.

The Mountain Magics seem to be doing fine, considering the soil. The Big Boys are getting gray spots on the bottom and end up rotting completely and this is before they ripen. We did ask someone at our garden center and they think the problem may be due to the extremes from dry to wet but I’m really not sure of that. We do water it every morning since they are in buckets and we’ve had some really hot days. What is the problem and is it treatable?

Answer 1

The problem is blossom end rot. This article will help you with that:
https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-blossom-rot.htm

Generally, this happens due to a lack of calcium in the soil. However, if you are getting this problem in containers, it is likely not a calcium issue, but rather a watering issue. Plants in containers have a hard time taking up enough water, which means they can't take up enough nutrients (like calcium). Increase your watering. These plants should be getting water at two times a day if you are experiencing temps above 85 F. This will provide enough water to allow the plants to take up the nutrients they need and should stop the blossom end rot.