You have raised your tomato plants correctly: provided them with high-quality potting soil, carefully fertilized them, pinched off suction cups or cut back low-hanging branches. Why do tomatoes split even after we have spent so much time and effort making sure everything goes perfectly?
Tomato cracking and splitting can come in two forms. In one case, concentric crack rings may appear around the top of the fruit. In the other, longitudinal cracks appear on the sides of the fruit, either along the indentations in heirlooms or along the surface of smooth varieties.
So is there any way I can prevent your tomatoes from splitting before they ripen? Let's examine this in detail and examine what causes it, how to prevent it, and whether your split tomatoes are safe to eat.
What causes tomatoes to divide?
Why do tomatoes crack? Usually it is related to watering. Source: docoverachiever
In short, tomatoes will split when the fruit inside grows faster than the tomato skin. What usually causes this is a sudden influx of the amount of water the tomatoes receive. Perhaps you were watering inconsistently, or a sudden heavy rain caused a deluge. Whatever the reason, it is most common when there is a long dry spell followed by plenty of water.
This problem is most common with almost ripe tomatoes. When the tomatoes near ripe, their skin doesn't grow as quickly. However, the plant will try to cram more water into the fruit and this will cause the skin to split open to expose the fruit. This type of cracking is known as radial cracking.
When it comes to heirloom tomatoes, you have another reason to ask: "Why are my tomatoes splitting?" You see, there is a price to be paid for all this flavor. Many types of heirloom, especially the large varieties of beef steak, crack in concentric circles around the top of the fruit as they grow and ripen on the vine. In most cases, these are fine cracks or lines on tomatoes rather than deep tomato cracks on the sides. Think of these as "tomato stretch marks" as the plant tries to make the fruit nice and juicy for you. Some heirloom tomatoes also crack on the sides.
Now that you know what causes tomatoes to crack and what causes tomatoes to pop on top, how do you keep tomatoes from cracking in your garden?
How to stop cracking tomatoes
Concentric cracking in heirloom tomatoes is common. Source: anneheathen
Here, uniform moisture is key. However, this is not always as easy to deploy as you might think. It really depends on how much water your tomatoes are used to.
People who grow their tomato plants in well-drained soil are likely to have fewer problems with split tomatoes or tomato cracks. Since these soils tend to drain excess water, an occasional downpour is not a problem as the water can easily drain away.
Since most raised bed mixes have excellent drainage, many people have fewer tomatoes in a raised bed. However, if you don't have raised beds, it is important that you prepare your garden bed in advance. Make sure it isn't hard-packed clay, as this can prevent good drainage. Work the soil down at least a foot or more and use plenty of compost and other organic matter to loosen it up. A small amount of perlite can provide ventilation and improve drainage.
Most of the cracking and crevice prevention already happens as you prepare to plant your tomato plants for the year. This prepares the plants for success right from the start.
Don't just loosen and change the planting hole. This creates a container sunk into the ground that can be filled with water. Instead, work the entire bed so that excess moisture can spread over a larger surface and be absorbed. This also makes it easier for you to later work in fertilizer on the soil surface.
When you plant your tomatoes, add some calcium to the soil underneath. You can use powdered eggshells or agricultural lime. This small dose should be enough to cover the entire lifespan of this plant so that you don't have to apply calcium afterwards. If you use a fertilizer optimized for tomatoes, they will usually contain calcium. So if you put some of it in the planting hole and then fertilize as usual during the season, this is also fine.
After planting, mulch wood shavings around the bottom of your tomato plants. Aim for about 2 to 3 inches of mulch and be sure to top it up throughout the season. If you have a soaking hose irrigation system, you can put this mulch directly on top of the drinking hoses. This layer of mulch keeps the soil moisture in the soil where it belongs.
There are a number of crack-resistant tomatoes available for purchase, both as seeds and as live plants. Before buying, read the information about the tomato plant. Even then, varieties that aren't crack-resistant are still good to plant as long as you look carefully. If tomatoes split, pick them right away.
Finally, pour evenly and evenly. You don't want to give your tomatoes any set or starvation conditions as completely drying out the soil between waterings can lead to other problems like flower end rot. Overwatering can lead to a number of fungal diseases. You want your tomato plants to be happy and healthy! So, maintain an even level of moisture in your soil.
Can you eat split tomatoes?
If you catch them fast enough, absolutely. If you watch your growing tomatoes closely, you can see ones that have radial cracks. Harvest these immediately, even if they are not yet fully ripe. Tomatoes continue to ripen from the vine.
If the tomato oozes or has a sour smell, add this to your compost. These are no longer viable. Rotten tomatoes also divide. So if it feels soft and mushy to the touch, this is a sure sign that it is compost-worthy. If it's not colored because of its diversity, that's another sign that it may not be okay.
But if the skin recently looks split and still smells sweet, it should be good to eat. Cut off the torn part to be on the safe side and compost that part. The rest of the fruit should be fine.
With these heirlooms creating the concentric circles around the top, just take a little more off the top. You still have a lot of tomato to enjoy. If the tomatoes crack or split radially, just cut around the crack again and take out the damaged part. The fruit should be good.
The green fingers behind this article:
Lorin Nielsen
Lifelong gardener
