Why Are My Tomatoes Deformed and Lumpy?

Some tomatoes come off the vine looking like they have been through a fight — puckered, lumpy, with scarred brown corky bands and folds at the blossom end. It looks dramatic, but this one is more cosmetic than catastrophic, and there is a specific reason it happens. The condition even has a name that perfectly describes its wrinkled look. Let me explain what causes it and how to get smoother fruit next time.

What you are seeing is catfacing

That distorted, lumpy, scarred deformity at the bottom of the fruit is called catfacing — named because the puckered folds were thought to resemble a cat's face. It shows up as ridges, cavities, holes and brown corky scar tissue, usually concentrated at the blossom end. It is not a disease, it is not contagious, and it does not spread. It is a developmental fault that was locked in weeks earlier, back when the flower was forming.

The main cause: cold during flowering

Catfacing traces back to something that disturbed the flower as it developed, and the most common trigger is cold weather. When temperatures drop too low, often below about 50 to 55 degrees Fahrenheit during flower formation, the flower develops abnormally. Some parts fail, others fuse, and the fruit that grows from that damaged flower comes out distorted. This is why catfacing is most common on the earliest fruit of the season, set during cool spring nights, and why it eases off as the weather warms.

The practical lesson is timing. Planting out too early, when nights are still cold, sets you up for catfaced early fruit. Waiting for settled warm weather, or protecting early plants from cold nights with a cover, prevents most of it.

Other triggers worth knowing

A few other things can cause or worsen catfacing. Large beefsteak and heirloom varieties are far more prone to it than smaller, modern hybrids — the bigger and more complex the fruit, the more can go wrong as it forms. Wide temperature swings, excessive nitrogen that drives lush abnormal flowering, and even certain herbicide exposure can all contribute. Heavy, hard pruning of young plants has also been linked to it. But cold at flowering remains the headline cause for most home gardeners.

Can you eat catfaced tomatoes?

Yes, absolutely. This is the reassuring part. A catfaced tomato is perfectly edible — the flesh is fine, the flavour is unaffected, and you simply cut away the scarred, corky bits at the bottom. It will never win a beauty contest, but it makes excellent sauce, soup or a rustic sandwich. So do not throw them out; just trim and enjoy them.

How to get smoother fruit

To reduce catfacing next season: hold off planting until nights are reliably warm, and shelter early transplants from cold snaps. Choose smaller-fruited or hybrid varieties bred to resist it if smooth fruit matters to you. Keep nitrogen moderate so flowering is normal rather than forced, and avoid heavy pruning of very young plants. With warm conditions at flowering, your later trusses will come through smooth and round even if the first few were lumpy.