Radial cracks on an heirloom tomato from the orchard |
Q. I have this problem. Our tomatoes develop cracks at times usually about half way to maturity. They also rot on the bottom.
A. Tomato cracking can be from the variety of tomato you are growing or it can be how you are managing your irrigations or a combination of both. Rotting of the bottom of the fruit can be caused by irregular irrigations.
Heirloom tomatoes with longitudinal cracks (top right and top left) from irregular watering |
Some varieties of tomatoes, particularly heirloom types, are subject to what are called radial cracks. These are concentric, circular cracks around the top of the fruit. These might be reduced by growing them under light shade probably know more than about 30%.
Cracks along the length of the fruit can be a particular problem after a heavy rain. Sometimes when the tomato fruit is near maturity very wet soil can result in a lot of water taken up by the plant with lots of it sent to the fruits. The fruit swells and cracks due to excess water taken in by the fruits and the skin.
Blossom end rot on tomato, picture submitted by reader |
Use a mulch on the soil surface to help keep the soil more evenly moist. This can result in less cracking to the fruits because the soil is kept more evenly moist. This can be straw, shredded or even sheets of newspaper or landscape fabric cut into strips. As I said, tomatoes will do better if they have some light shade when they are growing.