Why Are My Tomatoes Cracking? The Complete Guide to Preventing Split Tomatoes

Discover why tomatoes crack and learn proven methods to prevent splitting for a picture-perfect harvest

“If you are a gardener/farmer it is always too hot, too cold, too dry, too wet, too something” - Comatfarmer

Picture this: You've spent months carefully tending to your tomato plants, watching them grow from tiny seedlings into robust vines laden with fruit. Every day, you eagerly check your plants, anticipating that perfect moment when those vibrant tomatoes are ready for harvest.

Then comes the heartbreak. Instead of the smooth, perfect tomatoes you imagined, you find fruits split wide open with cracks radiating across their surfaces. If you've ever experienced this gardening disappointment, you're not alone.

In our Kitchen Garden, we're currently facing this exact challenge with our cherry tomatoes, which are particularly susceptible to this frustrating problem. I love having a couple cherry tomato plants near the door so I can pick one or two every time I walk past. While we'll still enjoy plenty of delicious tomatoes, I wanted to share what causes this common issue. You may not be able to prevent it entirely but you can reduce it in your garden.

If you are a farmer, it is too hot, too cold, too wet, too dry, or too something! - The Combat Farmer

For a few weeks, it has been really dry around here. Lawns were crunchy and if you had a vegetable garden, it was drying and shriveling if you hadn’t been irrigating. So I wrote this blog a couple of weeks ago about Smart Lawn Watering During Drought: 7 Essential Rules to Save Your Yard.

Then we got lots of rain for about a week. This is the perfect recipe for splitting tomatoes.

What Exactly Is Tomato Splitting?

Tomato splitting (or fruit cracking) happens when the inside of the tomato grows faster than its skin can accommodate. It's like trying to squeeze into pants you've outgrown—something's got to give!

This splitting occurs in two main patterns:

Radial Cracking: These vertical splits run along the sides of the fruit like spokes on a wheel. They're the more serious type of splitting and can lead to rot if not harvested quickly.

Concentric Cracking: These circular cracks form rings around the stem end of the tomato. While less severe, they still affect fruit quality and appearance.

The Science Behind the Split

Understanding why tomatoes crack comes down to two primary factors:

1. The Water Roller Coaster

The main culprit behind splitting is inconsistent moisture. When tomato plants experience drought followed by a sudden influx of water (from heavy rain or overenthusiastic watering), the fruit absorbs this water rapidly. This causes the flesh inside to expand faster than the skin can stretch, resulting in cracks.

Think of it like a balloon being filled too quickly. Eventually, it pops!

2. Environmental Triggers

Several environmental conditions can exacerbate splitting:

• Hot, humid weather during ripening

• Intense direct sunlight causing uneven ripening

• Temperature fluctuations between day and night

• High nitrogen levels in soil

Cherry tomatoes, like the ones in our garden, are particularly vulnerable due to their thin skins and quick growth rate.

5 Proven Strategies to Prevent Tomato Splitting

While you can't control the weather, you can implement these practical solutions to minimize splitting:

1. Water Consistently and Deeply

The single most effective prevention method is consistent watering. Aim for:

• 1-2 inches of water per week (including rainfall)

• Deep watering that reaches the root zone

• Morning watering that allows foliage to dry before evening

• Drip irrigation systems that deliver steady moisture

2. Apply Mulch Generously

A 2–3-inch layer of organic mulch around your tomato plants works wonders:

• Regulates soil temperature

• Prevents rapid evaporation

• Maintains steady moisture levels

• Reduces water stress during heat waves

I've found that straw, shredded leaves, or well-aged compost make excellent mulch choices for tomatoes.

3. Provide Shade During Peak Heat

During intense summer heat, consider providing afternoon shade:

• Install shade cloth (30-40% shade is ideal)

• Plant taller companion plants on the western side

• Use row covers during heat waves

This protection helps prevent the rapid fruit growth that often leads to splitting.

4. Harvest Strategically

Keep a vigilant eye on ripening fruit:

• Pick tomatoes at the "blush" stage (just beginning to ripen)

• Harvest before heavy rain is forecast

• Bring nearly ripe tomatoes indoors to finish ripening during periods of unpredictable weather

5. Choose Crack-Resistant Varieties

For future growing seasons, consider varieties specifically bred for crack resistance:

• 'Mountain Fresh'

• 'Defiant'

• 'Celebrity'

• 'Mountain Merit'

What About Already Split Tomatoes?

If you're already facing split tomatoes, don't despair! Tomatoes with fresh cracks are still perfectly edible—just be sure to:

• Harvest them promptly

• Use split tomatoes immediately in cooking

• Cut away any damaged portions

• Keep an eye out for signs of rot or mold

The Silver Lining

While split tomatoes may not win beauty contests, they often contain higher sugar levels due to the conditions that caused the splitting. Many gardeners (myself included) find that slightly split tomatoes can actually be sweeter and more flavorful!

In our Kitchen Garden, we're embracing our cracked cherry tomatoes as a sign of their intense flavor development. As I always say to fellow gardeners: perfect-looking produce is for supermarkets—character is for home gardens!

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Have you experienced tomato splitting in your garden? What methods have worked best for you to prevent it? Share your experiences in the comments below!

Notes from this week:

It has been an exciting week. At one point, I had four different species of tree frog on my back door. Earlier that day, I had an encounter with a Timber Rattlesnake right outside my front door. Check out the photos and the provided links.