Look what we have.
We also have this, which isn’t as exciting….
It’s called Blossom End Rot. That’s the bottom of the tomato, where the blossom was. It is caused by a lack of calcium in the baby tomato cells. Luckily, it’s not a disease, and won’t spread to other plants. The same condition also often occurs in watermelons and peppers. It happens after:
a) periods of rapid growth followed by a dry spell
b) heavy rains that cause calcium loss in the soil
We’ve had both while our tomatoes were growing.
When we planted the tomatoes, we added a couple of tablespoons of lime (maybe not enough?) to give them a calcium boost. We also used a 10-10-10 fertilizer.
Gardening Lesson: The numbers on a bag of fertilizer represent the percentage by weight of the main nutrients plants need–nitrogen, phosphorous and potassium–always in that order.
More ideal would have been a fertilizer low in nitrogen, but higher in phosphorus. The 10-10-10 was free though and we garden and landscape our yard based on what we can get for free or really cheap.
A spray containing calcium (in the form of calcium chloride) can be used on the plant to help increase calcium levels and prevent Blossom End Rot on later ripening fruits. Follow the directions though. It’s a concentrate and using too much can burn the leaves.