Last Updated: April 7, 2023
One of the most common concerns among tomato growers is cracking or splitting skin. If you have experienced this in your garden, you know it can be disheartening. It happens frequently, so you may wonder, why do tomatoes split?
In this article, I will go through several causes for tomatoes cracking on the vine. I will also offer some tips and tricks to help prevent split tomatoes in the future.
In This Article:
- What causes split tomatoes?
- How to prevent splitting
- Different types of cracking
- Can you eat split tomatoes?
- Which tomato varieties don’t split?
What Causes Tomatoes To Split?
Tomatoes can be very temperamental plants. In other words, imperfect growing conditions can lead to a whole host of issues with your plants. From yellowing leaves to curled leaves and of course, tomatoes splitting.
Simply put, tomatoes split due to excessive watering, especially after a period of drought. The water causes the fruits to expand faster than skin can grow, cause it to split. Some tomato varieties are more susceptible to cracking due to thinner skin.
Adopting an even watering schedule can help avoid the issue altogether. Keep the soil moist at all times, but never soaking wet. If your plants receive frequent rainfall, make sure that the soil drains well.
Excess water is the primary cause of tomatoes splitting. The plant roots take in too much water, causing the fruits to expand quicker than new skin can form. The result – cracked skin and exposed tomato flesh.
The best way to prevent cracking is to avoid providing too much water. Over-watering is a common issue with home vegetable growers. It is easy to love your garden too much.
For tomatoes, under-watering can be just as problematic, so I recommend adopting a consistent and even watering schedule. When tomatoes are full-grown, they will use water fairly consistently.
Though I can’t recommend a specific number of days to wait between watering, there are some ways to know that your plants are thirsty. Check a few inches beneath the soil around the plants – if it is damp, don’t water yet.
If it is hot or dry, the plants may need water every 3 or 4 days. However, when weather is cooler or more damp, the plants only need watering every 7 days or so.
Most importantly, if your tomatoes are cracking, they are probably receiving too much water, so cut back! Another watering-related cause of cracking is inconsistent watering.
2. Inconsistent Watering
Although this may seem the same as over-watering, it is a different issue. Inconsistent watering means that your plants are left to dry out for too long, and are then given lots of water to compensate.
The previously dehydrated tomato plant reacts to the sudden influx of water by taking all of it up into the plant and the fruits. The fruits suddenly expand and grow quickly, but the skins can’t keep up with the watery inner growth.
This can happen in nature when a period of drought ends with a heavy rain storm. However, in pots or raised beds, we can prevent it by watering more evenly.
Again, the solution is to provide water on a more regular basis, avoiding periods of excessive dryness.
Tip: If your plants do dry out, try to harvest any ripe or soon-to-ripen fruits before watering lightly. Avoid the temptation to overwater!
3. Poor Drainage
In a similar vein to excess watering, poor draining soil can lead to the same result. If excess rainfall or irrigation cannot drain, the roots will take in too much water.
Allow potted plants to fully drain during watering by removing the bottom saucer. Raised beds have good drainage by design, but in-ground gardens may need help. If your garden is located on flat land, you may need to plant on mounds.
You can also dig drainage channels in the soil to allow heavy rainfall to flow away from the roots. Poor drainage can also lead to other problems like root rot, drowning roots, and edema.
4. Not Picking Ripe Fruits
It so often happens that a perfectly ripe tomato is left on the plant 1 day too long. A single rainfall can cause that perfect fruit to split the very next day.
Make it a habit to harvest your ripe tomatoes ASAP. It should be a daily routine to inspect the plants for nearly or fully-ripened fruits, and pick them right away.
This will not only help avoid cracking, but will encourage the remaining tomatoes on the plant to ripen more quickly. It can also stimulate the plant to produce additional flowers and fruits.
5. Poor Air Circulation
Tomato plants use water in a few ways. One is by putting it into the fruits. Another is through transpiration from leaves.
If there is a lack of airflow, the foliage of your plants can become stuffy and humid, leading to issues, like blight. It can also slow down the process of transpiration, causing slower water usage, which can increase likelihood of fruits splitting.
Poor air circulation can also lead to poor water evaporation from the surface soil. However, this is less concerning than the transpiration issue. Trim low branches throughout the season to keep the bottoms of your tomato plants away from the soil.
6. Susceptible Tomato Varieties
Unfortunately, many beautiful tomato varieties have thinner skin, causing susceptibility to cracking. However, there are many varieties with thicker, crack-resistant skin perfect for home gardeners!
Search your favorite seed provider for any varieties that are ‘crack-resistant.’ Since this issue is so well known, many seed sellers will seek out varieties that naturally resist splitting.
Skip to our list of split-resistant varieties below.
How To Prevent Tomatoes From Splitting
Although it may seem clear from the reasons listed above, lets go through the preventative measures you should take to avoid cracked tomatoes.
In short, to avoid split tomatoes, use a consistent and even watering schedule, avoid periods of excessive drought, provide adequate drainage, and pick tomatoes promptly when ripe. Beyond these steps, you can also try planting crack-resistant varieties and bottom pruning for better airflow.
Here are some tips for how to stop tomatoes from splitting:
- Water evenly. Watering practices are by far the most important to control. As we now know, tomatoes crack due to excessive water intake and rapid fruit growth. If your plants are used to an even watering schedule from day 1, they will adopt an even growth rate for fruits. Avoid drought by keeping the soil moist and evenly watered. Watch for hot weather, as the plants will require more water.
- Provide drainage. This is especially important for in-ground gardens. Groundwater needs to flow away from your gardening location. If rain tends to pool in or around your garden, you’ll need to adjust the design. One option is to plant tomatoes on top of mounds to allow water to flow away from the roots. For raised beds and container plants, just ensure that water can escape from drainage holes.
- Bottom prune for airflow. It is important to allow tomato plants to breath. Pruning low branches is beneficial for this and also for avoiding soil-borne diseases from infecting the plants. Prune excess foliage from the bottom up to allow a clear path for air to flow around the plants. This can also help excess water in the soil evaporate more readily.
- Pick ripe tomatoes promptly (or early). Check your tomato plants daily for any ripe fruits. Picking fruits promptly will not give them enough time to continue expanding and cracking. If you are having lots of cracked tomatoes, you can pick some fruits before they are fully ripe and allow them to ripen off the vine.
- Harvest tomatoes before heavy rain. Watch the weather forecasts for upcoming rain. If there is a storm approaching, pick any nearly-ripe tomatoes from the plant to avoid them cracking from the excessive water. Allow the unripe fruits to finish ripening in a closed paper bag indoors. Read more about harvesting tomatoes here.
- Pick cracked tomatoes. If you see cracked tomatoes, harvest them right away. The split skin is highly susceptible to mold and rot, and will become unusable quickly if left on the plant. If you see black mold or rot in the split skin, do not eat that portion of the tomato. The rest may still be salvageable, but picking fruits promptly will help avoid loss of your crop.
Even if you follow these methods, some tomato varieties will probably still crack. Some types are simply more prone to cracking due to naturally thin skins.
Types of Tomato Cracks
There are two distinct types of cracking on tomatoes. Different varieties will be more or less prone to the different types based on their physical shape. Radial cracking is usually more problematic than concentric cracking.
Most common on irregularly shaped fruits, radial cracking is the more serious form of splitting. These cracks run vertically on tomatoes, usually beginning at the stem and spreading down the side.
Due to the larger size, radial splits in your tomatoes are highly vulnerable to mold and rot. These cracks are typically too large to quickly heal, causing rot to set in quickly.
Harvest any tomatoes that have radial cracks immediately. If the cracks have turned black, make sure to remove that portion of the fruits before consuming. The remaining flesh is usually perfectly edible.
If you sell fresh produce, this type of cracking can be devastating. Use the methods above to help prevent future cracking.
This type of splitting is usually less severe, presenting in horizontal, concentric circles around the stem of tomatoes. These cracks are more common on smooth, spherical tomato varieties.
Concentric splitting on tomatoes usually heals quickly, preventing mold and rot from setting in. However, you should likely still pick split fruits promptly.
If cracks occur before the fruit is ripe, do your best to adjust the watering schedule and improve aeration. If left on the vine too long, concentric cracks can still lead to rotting.
The healed cracks in the skin will usually have a tougher texture, but are okay to eat. Avoid any deep-black spots by cutting them away before using in food.
Blossom End Rot
Blossom end rot is a different tomato issue, but it can potentially be confused for cracking. It will usually appear starting at the bottom of tomatoes as a large black spot.
Blossom end rot is caused by incomplete skin formation, usually as a result of a calcium deficiency. Provide calcium via seabird guano or a cal-mag foliar spray to help avoid blossom end rot.
Fun fact: Blossom end rot is not actually rot, but rather unformed fruit skin. This is caused by a lack of available calcium in tomato plants.
Can You Eat Tomatoes with Cracks?
Although they may be ugly and imperfect, cracked tomatoes are not necessarily a complete loss. If you act quickly, you can likely make use of split tomatoes.
In short, cracked tomatoes are usually okay to eat. Cut away any dark areas and avoid mold or rot on split tomatoes. Radial cracks in tomatoes are more likely to rot than concentric cracks.
If you catch it early enough, you can pick the tomatoes right away and cut out the affected areas. This will help prevent spreading of any mold or rot, and the tomatoes can be frozen or otherwise preserved for use.
Split-Resistant Tomato Varieties
One of the easiest methods to avoid cracking tomatoes is to plant varieties that resist splitting. These are usually thick-skinned tomatoes. Here is a list of a few tomato types that are crack-resistant.
These adorable cherry tomatoes are thick-skinned and very attractive in the garden. Many of the smaller varieties are resistant to cracking, but not all. Plant these in the garden for a worry-free tomato plant with lots of style.
These medium-sized fruits are great for canning or slicing fresh. They are smooth and round, helping to avoid the dreaded radial cracking. They also have thicker skin, making them easy to remove for sauces or soups. This variety is classic and beautiful, with the peace of mind of crack-resistance.
These unique, pouch-shaped tomatoes are gorgeous in the garden. Their larger size may be what you are looking for, and they are known to resist splitting. The beautiful orange color is also a welcome addition to any home vegetable garden.
These pinkish-red tomatoes are beautiful and functional. Large fruits are said to often exceed 1lb in weight, and are said to be prolific producers. These crack-resistant tomatoes are another attractive tomato to add in the garden.
If you want to grow some truly remarkable tomatoes in your garden, why not add some purples and blues? The Blue Beauty tomato is a gorgeous heirloom variety that has the benefit of rarely cracking. Deep blueish-purple skin covers a brilliant red flesh inside.
This smaller variety has almost a heart-like shape to it, hence the name. The delicious tomatoes rarely crack and offer great yields with minimal effort. They can be picked early for a more tangy flavor, or left to ripen fully for a super-sweet taste. Great for snacking!
I hope this article helped you learn why tomatoes split and crack on the vine. There are some simple measures that you can take to avoid tomato cracking in the future. Good luck and happy tomato growing!