Q: My tomatoes are cracking in circles around the top. What causes this to happen?
A: There are two different kinds of cracking commonly found on tomatoes. One of the cracks starts at the stem and flows downward toward the blossom end. This type of downward crack is called a radial crack. The other crack, which is the one you have, makes circles around the top of the fruit. It is possible to have both types on the same fruit. Cracks are caused when the fruit internally grows more quickly than the outside. This fast internal growth spurt causes the external skin layer to split open forming a crack. There are varieties which have a resistance to cracking but that does not mean they cannot crack only that cracks will probably occur later in the maturing process. Environmental conditions such as huge temperature differences and/or inconsistent irrigation contribute to the formation of the cracks. Not much can be done about the temperature variations especially when fruit is maturing during the spring however irrigation can be controlled by the home grower. Just be sure to water your tomatoes consistently but remember too much is not a good practice either. The vegetable is still safe to eat so there is no need to throw it away.