What’s Wrong With My Tomato?

Sun-ripened tomatoes easily earn their keep in even the smallest garden patch. But growing the perfect tomato can prove somewhat elusive. Flip through our gallery to diagnose your tomato problems — and discover strategies to set your world of vine-ripened flavor right again.

Those dark, sunken spots on the bottom of tomatoes are blossom end rot. It's so common that in tomato circles they call it BER for short. It's not a disease but a symptom of calcium deficiency. It occurs due to uneven watering (wet-dry cycles in soil), too-high nitrogen or root damage. You can eat tomatoes with BER — just cut the bottoms off. For a quick fix, treat plants with a calcium spray for BER. Keep soil consistently moist; using mulch helps. Test soil when tomato harvest ends. Amend as needed.

When tomato plants look healthy and flowers appear but drop without setting fruit, it's usually not your fault. Blame this one on the weather. When day temperatures linger around 85 F to 90 F and nights stay above 75 F, tomato flower pollen becomes unviable. Once the hot spell passes, flower pollination will resume and tomatoes will form. Until then, keep plants well-watered and fertilized, so they're ready to jump back into production. In regions where summer sizzles, grow heat-tolerant varieties, like 'Solar Flare', 'Summer Set', 'Heatmaster', or 'Phoenix'.

A cracked tomato means that while the fruit was ripening, the water supply was uneven. A heavy downpour that soaks soil can result in roots sending huge amounts of water to ripening tomatoes — so much so that they pop their skins. Cracked fruit is edible, but the cracks are more susceptible to mold. Eat ripe, cracked tomatoes before ones with smooth skins. Prevent the condition by mulching soil and watering tomatoes deeply twice a week, instead of giving plants a little water every day. When heavy rainfall is in the forecast, pick tomatoes that are almost fully colored.