One of the main reasons for blossom end rot on tomatoes is improper fertilization.
An expert of the online publication Belnovosti, agronomist, and landscape designer Anastasia Kovrizhnykh talks about three annoying mistakes summer residents make when fertilizing tomatoes.
The first mistake is overfeeding. This worsens the absorption of calcium by the roots, the deficiency of which provokes the appearance of apical rot.
The second mistake is watering with water containing a high content of iron and other impurities.
When interacting with calcium, these impurities convert it into an insoluble form.
Thirdly, you should not use boric acid, it is a calcium antagonist.
Excess boron also reduces the shelf life of tomatoes and makes them vulnerable to late blight.