Why Do Tomatoes Split?

Ripe red tomato with split in skin
Dorling Kindersley/Dorling Kindersley/Getty Images

One of the more frustrating things about growing tomatoes is watching a tomato ripen on the vine, slowly growing and changing from green, to pink, to red.... and then looking one morning and seeing that that tomato you've been waiting for has split. Tomatoes split most often just as they're ripening, and, if you have several ripening at the same time, it's likely that all of them will split.

What Causes Tomatoes to Split?

Tomatoes split because of fluctuations in the amount of water they get. If it's been very dry, and then all of a sudden you get a couple of inches of rain, the insides of the tomatoes grow faster than the outer skin is able to, and the tomatoes crack. While this can sometimes be a problem when the tomatoes are still green, it happens more often to tomatoes that are starting to ripen, mainly because the outer skin becomes more fragile the closer a tomato gets to ripening.

How to Prevent Tomatoes from Splitting

While you can't always prevent tomato splitting (a rainstorm that dumps several inches of rain on your garden in a few hours will result in split tomatoes no matter what you do!) you can make it less likely that your tomatoes will split by doing the following:

  • Water Regularly and Deeply. You should water your tomato plants every two to three days during the summer. When you water, water at ground level (spraying the leaves can result in the spread of diseases like blight and septoria) and water deeply. Regular, deep watering will reduce the effect of a sudden rainstorm, because your plants won't be going from dry conditions to sudden wet conditions, which causes splitting.
  • Mulch. Provide your plants with a good two to three inch layer of organic mulch such as straw, pine needles, or shredded bark. This will maintain more regular soil moisture levels, and you'll deal with less splitting.
  • Look for Resistant Varieties. In general, the thicker the skin, the less prone a tomato is to splitting. Most modern hybrids seem to resist splitting.

    Splitting tomatoes are just one of those things that every vegetable garden seems to deal with at one time or another. The good news is that split tomatoes are still edible, so feel free to harvest and eat them. They won't store long, so be sure to eat or cook with them right away.

    Now that you know how to protect your tomatoes from splitting, here's hoping you have a beautiful, bountiful harvest.