If you grow tomatoes, chances are you've watched your beautiful harvest ripen, only to look 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 tomatoes ripening at the same time, it's likely that all of them will split.
Why Tomatoes 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 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 as the tomato ripens.
It's important to note that there is a difference between splitting and cracking. Some of the larger heirloom varieties of tomatoes, such as beefsteak tomatoes, do tend to crack a bit at the top. This is not the same issue as splitting, and it's fine to allow those tomatoes to stay on the vine.
How to Prevent Tomatoes from Splitting
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. But 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 because 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.
- Pick Tomatoes Early. Your tomatoes are almost ripe, and you're expecting a major rainstorm. Now is the perfect time to pick your tomatoes before they're overwhelmed by extra moisture. Tomatoes will ripen on or off the vine, so go ahead and harvest those that look nearly reading for picking.
- Provide Good Drainage. By planting your tomatoes in raised gardens or placing crushed seashells at the bottom of containers or planting holes you can lessen the possibility that your tomatoes will be oversaturated by water. In addition, the extra calcium provided by seashells may strengthen the tomatoes, making them less prone to cracking.
What to Do if Your Tomatoes Split
If your tomatoes do split, it's important to harvest them as quickly as possible. Split tomatoes are much more susceptible to rot and parasites.
While you may not be able to completely avoid splitting, 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.