Here’s the single most useful thing you can learn about ugly tomatoes: almost nothing that goes wrong with the fruit is a disease. The black-bottomed ones, the cracked ones, the scarred and puckered and bleached ones. Nearly all of it is weather and water wearing disguises. No fungus, no bacteria, no bug.
That’s genuinely liberating, for two reasons. It means nothing in the spray aisle will fix any of it, so you can save your money. And it means the real fixes are things you control. How you water, how much leaf you leave on the plant, and which varieties you grow. So let’s go disorder by disorder. What it looks like, what actually causes it, how to stop the next one, and the question everyone secretly wants answered: can I still eat this?
Blossom end rot: the black-bottomed classic
The look: a sunken, dark, leathery patch on the bottom of the fruit, the blossom end, often showing up just as the first fruits of the season size up.
Everyone’s first guess is disease, and it’s wrong. Blossom end rot is a calcium failure inside the fruit, and here’s the twist that matters. As Missouri’s IPM program explains, the soil almost always has plenty of calcium. Our dedicated blossom end rot guide digs into why the popular fixes fail. The problem is delivery. Calcium travels into the fruit dissolved in water. When watering swings from dry to soaked to dry, or a heat wave spikes the plant’s water demand, the calcium supply line to the fruit fails. The tissue at the far end dies.
That’s why the eggshells, antacids, and calcium sprays people throw at this mostly do nothing. The actual cure is boring: steady, even, deep watering with a mulch layer to smooth out the swings. The rare true soil-calcium shortage is a separate story covered under nutrient deficiencies. The epsom salt folklore around this disorder is dismantled in our feeding myths section, since magnesium actually competes with calcium and can make rot worse.
Eat it? Yes. Cut the black end off; the rest of the tomato is fine. And take heart, early-season rot often clears up on its own as watering evens out.
Cracking and splitting: the rain casualty
The look: cracks either radiating out from the stem like spokes (radial) or circling the shoulders in rings (concentric).
The mechanism is pure physics. The inside of the fruit swells faster than the skin can stretch. Per Missouri’s fruit-disorder guide, the classic trigger is heavy rain or irrigation landing on somewhat dry soil. The full crack taxonomy, rings versus splits, lives in why do tomatoes split. The thirsty plant gorges, the fruit balloons overnight, the skin loses. Ripe fruit cracks easiest, and heirlooms crack far more readily than modern hybrids, many of which are bred crack-resistant.
Prevention is three-legged. Even moisture so there’s never a gorge moment (mulch again, the cheapest insurance in the garden). Picking ripe and near-ripe fruit before a forecast downpour, a trick straight from our harvest timing guide. And choosing resistant varieties if cracking plagues you yearly.
Eat it? Fresh cracks, absolutely, and promptly. Old cracks that have gone dark or moldy have let rot move in, so trim generously or pass.
Sunscald: the sunburn
The look: a pale, whitish-yellow, papery patch on the side of the fruit that faces the sun, which later collapses and can grow secondary mold.
Tomatoes need sun; the fruit doesn’t. Fruit is meant to ripen in the dappled shade of its own canopy. Sunscald happens when that canopy disappears, usually because of over-enthusiastic pruning or a disease that stripped the leaves. The full mechanism and the safe salvage rules are in our sunscald guide. It’s most brutal when shade vanishes suddenly and the fruit has no time to adjust.
Prevention is leaf cover. Prune with restraint, the balance we walk through in the pruning guide. If disease is defoliating the plant, that’s the fire to fight, via the disease triage hub. Eat it? Trim the scalded patch; if secondary rot hasn’t moved in, the rest is fine.
Catfacing: the puckered mutant
The look: badly deformed fruit, flattened, lobed, with corky brown scars and crevices at the blossom end, sometimes cavities running deep into the flesh. Ugly enough that people assume something sinister.
The cause is set way back at flowering. Minnesota Extension lists the suspects: cold temperatures while the flower was forming, physical disturbance to the bloom, or drifting hormone-type herbicides. Cold is the usual culprit. That’s why catfacing shows up on the earliest fruit of the season, the ones whose flowers endured chilly spring nights, and why the big-fruited heirlooms are far more prone than cherries.
Prevention is mostly patience. Don’t rush transplants out into cold nights, the same discipline preached in our planting guidance. If it recurs badly, note that variety choice matters, per our variety type rundown. Eat it? Yes, and this is the classic “ugly but delicious” tomato. Cut around the corky scar.
Green and yellow shoulders: the ones that won’t finish
The look: the fruit ripens red except the shoulders around the stem, which stay stubbornly green or turn hard and yellow.
This isn’t slow ripening, it’s a heat injury. High temperatures shut down lycopene production, the pigment that makes red. Missouri’s guide adds a second factor: potassium running low right when fruit demand peaks. So a hot spell plus a hungry plant paints yellow shoulders. Keep leaf cover shading the fruit, and keep potassium in the feeding program through fruiting. Many modern varieties carry the “uniform ripening” gene that sidesteps this entirely. Eat it? Cut the hard shoulder off, enjoy the rest.
Tomatoes just not ripening at all
Worth its own entry because the cause surprises people: tomatoes ripen best between roughly 65 and 75 degrees, and when a heat wave parks temperatures above 85, ripening slows or stops entirely. A vine full of stubborn green fruit in high summer usually isn’t sick, it’s stalled.
Two moves. Wait for the weather to break. Or pick fruit that’s reached full size (or better, first blush) and finish it indoors where it’s cooler, which works perfectly for reasons explained in our breaker stage breakdown. The indoor techniques themselves, counters, bags, and all, live in the green tomato ripening guide.
The rot-on-the-vine disambiguation
One last fork in the road, because “my tomatoes are rotting” splits two very different ways. Rot at the bottom of the fruit only, on an otherwise healthy plant: that’s blossom end rot, top of this page, a watering story. Rot in greasy brown patches anywhere on the fruit, with the leaves also blotching and collapsing: stop reading this page. That’s late blight, it moves in days, and the disease identification guide is where you need to be right now.
And for the record on a couple of minor oddities. Hollow, light, puffy fruit traces to poor pollination during cool or hot spells, and thin brown zipper-like scars down the fruit’s side are a cosmetic pollination leftover. Strangest of all, an overripe tomato can start growing sprouts from the seeds inside it, which looks alarming and is mostly harmless. Both are eat-around-it harmless.
Frequently asked questions
Why do my tomatoes have black bottoms?
That’s blossom end rot, a calcium delivery failure caused almost always by uneven watering rather than a lack of calcium in the soil. It’s not a disease and sprays won’t fix it. Water deeply and consistently, mulch to hold moisture steady, and cut the black end off, the rest of the fruit is fine.
Why are my tomatoes cracking and splitting?
The inside grew faster than the skin, almost always because heavy rain or irrigation hit dry soil and the fruit swelled overnight. Keep moisture even with mulch and steady watering, pick ripe fruit before storms, and consider crack-resistant hybrids, since heirlooms split most easily.
Can I eat tomatoes with blossom end rot, cracks, or catfacing?
Almost always yes. These are physiological disorders, not diseases, so trim away the affected part, black bottoms, corky scars, scalded patches, and eat the rest. Skip fruit where cracks or damage have gone moldy or foul, since rot organisms may have moved in.
Why do my tomatoes stay green and never turn red?
Usually heat. Ripening stalls when temperatures sit above about 85 degrees, so summer heat waves park whole vines at green. Either wait for cooler weather or pick full-size fruit and ripen it indoors, where it will color up normally with no flavor loss.
Why are my tomatoes deformed and scarred on the bottom?
That’s catfacing, set in motion weeks earlier when cold nights disturbed the developing flower. It shows up most on early fruit and big heirloom varieties. It’s cosmetic, the fruit eats fine around the scarring, and planting after nights warm up prevents most of it.
Bottom line: ugly fruit is the garden confessing its weather and watering history, not an infection. Steady deep watering with mulch prevents the big two (rot and cracking). Restrained pruning prevents sunscald, warm-night planting prevents catfacing, and nearly everything trims down to a perfectly good tomato. When the plant itself looks sick alongside the fruit, that’s your cue to switch to the complete troubleshooting hub.