Have you been in your garden, shaking your head and wondering, “Why are my tomatoes splitting?”
The science behind why tomatoes split is pretty straightforward. But to figure out how to keep tomatoes from splitting in your garden, you’ll need to look at the unique conditions in which you’re growing them.
Read on to learn what causes tomatoes to split, how serious it is, and how to prevent this common problem from occurring in your home garden.
Why Do Tomatoes Split?
An inconsistent supply of water is the primary cause of cracked or split tomatoes, but improper drainage or poor soil nutrition can also be contributing factors.
Fluctuations in Water Availability
A tomato will split when a sudden change in the plant’s water supply leads the inside of the fruit to start growing faster than the skin, causing it to burst open.
You’ll see this happen most frequently with ripe tomatoes. Because green tomatoes have thicker skin, it’s still possible they can split, but it’s much less likely.
Most often, what causes tomatoes to split is sudden rainfall on outdoor plants growing in otherwise dry conditions. A thirsty tomato plant with sudden access to water will tell the fruit to absorb as much water as possible.
Forgetting to water your tomatoes or overwatering them can also cause cracks or splits, as can a sudden shift from wet to dry weather.
Improper Soil Nutrition
Even if you consistently provide your tomatoes with the correct amount of water, they can still split if the plant’s soil conditions aren’t right.
Using high-quality, well-draining, organic soil in your garden is best for all your plants, but it’s especially important for preventing tomatoes from splitting.
Insufficient drainage, calcium deficiency, and an excess of nitrogen in the soil can all contribute to cracking in tomatoes as well.
Two Types of Split Tomatoes
You may see two different types of splits or cracks on your tomatoes:
Radial cracks are vertical splits that usually start near the stem and reach down to the bottom of the tomato. Radial splits are the most damaging, and the fruit will rot if left on the vine for long.
Concentric cracks tend to be shallower and less severe than radial cracks. They appear as rings around the top of the fruit and often heal quickly before pests and bacteria can enter.
How To Prevent Tomatoes from Splitting
Here are five steps to take to grow healthy tomatoes and prevent them from splitting.
1. Provide Consistent Water
Providing your tomatoes with the right amount of water consistently is the most important part of preventing tomatoes from cracking.
How Frequently to Water Tomatoes
How much you need to water your tomatoes depends on the climate and weather conditions where you’re growing them.
In the summer season, most tomatoes will need about an inch of water per week. If you expect rain, factor that in and provide less supplemental water. In very dry weather, water tomato plants more frequently, about every two to three days.
Impact of Rainfall on Tomato Plants
If heavy rainfall drowns your tomato plants, they’ll take in more water than they need. And the shock from the sudden change can traumatize the plant as well, further increasing the likelihood of splits in your tomatoes.
If you live in an area with frequent or even intermittent heavy rainfall, you might want to consider growing your tomatoes in a controlled environment. A greenhouse or other sheltered area will allow you to control the plant’s water supply and keep it consistent.
Use the Right Hose
Since preventing tomatoes from splitting depends so much on the plant’s water supply, finding the right hose for your garden is critical.
Soaker hoses or drip irrigation systems are your best options. Both provide a steady and consistent supply of water delivered directly to the plant’s roots, eliminating the risk of accidental overwatering.
These types of water delivery systems will also keep your plant’s foliage dry, reducing the risk of blight and other soil-borne diseases.
Signs You Are Overwatering
Keeping tomatoes from cracking comes down to getting them just the right amount of water.
If the plant’s lower leaves appear bloated or swollen, you might be overwatering.
Another sign of overwatering or insufficient drainage is soggy, wet soil around the base of the tomato plant.
2. Provide Proper Drainage
Planting tomatoes in containers or raised garden beds is the best option for providing the plants with sufficient drainage.
Tomatoes have expansive root systems, so make sure to plant them in loose soil, with the plants spaced at least two feet apart.
Mulch Around Plants
To keep the soil evenly moist, spread about a two-inch layer of mulch around the base of your tomato plants.
Grass clippings, pine needles, and straw are all great options for organic mulch.
You can also use well-decomposed compost, which has the added benefit of enriching your soil with nutrients. But when using compost as mulch, you risk attracting flies or other insects to your plants.
3. Use the Right Fertilizer
Which fertilizer is best for feeding your tomato plant depends on the composition of the soil it’s planted in.
Not sure which nutrients your soil may be lacking? Grab an at-home soil test kit online or at your local garden shop. These tests will tell you how much nitrogen, phosphorous, and potassium is present in the tested soil.
A calcium deficiency can be another reason why tomatoes split. This mineral not only promotes healthy cellular function in the tomato, it also specifically affects the way water moves inside the plant.
Powdered eggshells are a great calcium supplement that you can prepare at home. Just crush clean, dry eggshells into a fine powder, and add it directly to the soil. Agricultural lime and tomato-specific fertilizers can also do the trick.
You only need to add calcium to the soil once, when first planting your tomatoes.
4. Pick at the Right Time
Harvesting at the right time is key to preventing tomatoes from cracking.
Before They are Ripe
You don’t need to wait for tomatoes to ripen on the vine.
In fact, it’s best to pick tomatoes when they reach the breaker stage. That’s as soon as they start to turn pink. They will be fully mature at that point, and as big as they’re going to get.
Keep your harvested tomatoes at room temperature (around 70 degrees) and they will continue to ripen naturally. They’ll be ready to eat when they develop their final, rich red color.
A sudden influx of water is the main reason why tomatoes split. So it’s good idea to look for and remove any ripe or blushing fruit before you water, or when you’re expecting heavy rain soon.
Picking tomatoes before watering will also give you the most flavorful fruit, since the added water essentially dilutes the tomato’s flavor.
5. Grow Split-Resistant Varieties
There are several delicious varieties of tomatoes that are resistant to cracking and splitting.
Consider planting one or more of these cultivars if you’re concerned weather conditions in your area may disrupt your otherwise impeccable watering routine.
Large and Medium-Sized Varieties
Love a big, juicy slicing tomato? Try growing Arkansas Traveler, a split-resistant heirloom tomato variety.
Other large and medium-sized tomato cultivars that resist cracking are Pink Girl F1, Jet Star F1, Plum Regal, and Celebrity.
Small Slicers and Tiny Tomatoes
Early Girl F1 is a mildly sweet, slightly tangy slicing tomato that resists splitting and most common tomato diseases.
Other great split-resistant varieties include Juliet, a plum-shaped hybrid grape tomato, and Black Cherry, a savory cherry tomato with a sweet and slightly smoky flavor.
Can You Eat Split Tomatoes?
You might wonder what to do with the cracked tomatoes in your garden.
Don’t worry! You can still safely eat split tomatoes if you catch the splitting quickly and pick them immediately.
Before you eat a cracked tomato, just give it a quick inspection. Consider the size and depth of the split.
If the crack is shallow and the tomato still smells sweet, then it’s safe to eat. Just cut around the crack to remove the damaged part, and you’re all set to enjoy the rest of the fruit.
A deep crack, on the other hand, is more likely to allow pests, bacteria, or fungi to enter the fruit. And sour smells or oozing indicate the tomato has started to rot and is no longer viable.
Now You Know Why Tomatoes Split
You’re one big step closer to finding the answer to the question, “Why are my tomatoes splitting?”
All that’s left is to pay a visit to your tomato garden and see which of the five simple steps outlined above you might need to take to prevent your tomatoes from cracking or splitting.
Have more questions about tomato care? Visit our Tomato Plants page on the website for everything you need to know about planting, growing, storing, and eating the best garden-fresh tomatoes.