Bottom of tomato is black and shrunken

by George
(Surrey BC)

The bottom of my tomato is black and shrunken up. The top is good though. What is it and can I still eat the rest of the tomato or is it diseased?

The problem is called blossom end rot. It is a physiological disease caused by a either a lack of water to move needed calcium up to the blossom or cool temperatures while the blossom was forming. It is not a disease.

Early fruit sets are more prone to this than later fruit sets in northern gardeners (early cool temperatures) while more southern gardeners are more prone to suffer water stress.

The rest of tomato is edible although not very visually appealing.

Solution is to water enough and protect from cool temperatures.

In very rare cases, it may be a deficiency in the soil calcium but bet on watering and temperature.