Yes, it's the beginning of that wonderful time of year, when you go out to pick that first delicious tomato after people like me told you tomatoes were so easy to grow. But instead of finding luscious, red fruit, you find something that makes you want to slap a baby seal. Don't do that -- it'll show up on YouTube and you'll be forced to flee the country. Instead, find out how to prevent these most common causes of tomato despair.
Potential Seal-Slapping Problem #1 -- Blossom-end Rot Blossom-end rot (above) manifests itself as a disgusting, blackish rotten spot on the end of the tomato opposite the stem. It results when the plant can't take up enough calcium from soil to build good cell walls, usually because roots are stressed due to repeated large swings in soil moisture.
What to do: Sprinkle a cup of lime around the base of each plant and water it. Then mulch around the plant to help keep the soil evenly moist, but not wet. In time, blossom-end rot should disappear.
Potential Seal-Slapping Problem #2 -- Catfacing
I know there are a lot of cat-haters out there (people with obvious mother issues), but was it really necessary to name this gross deformity of tomatoes after cats? On behalf of all felines, my cat, Ketchup, would like you to know how offensive this is. "It really looks more like a slobbering dog," he observes.
Catfacing ("Dogfacing," says Ketchup) causes bizarre dimpling, pimpling, lumping, and bumping of the fruit. Like blossom-end rot, it results from growing conditions -- usually a sudden stretch of unusually cool weather (below 60 degrees) when the plant is setting fruit. As soon as the weather warms up, catfacing disappears.
What to do: Wait for better weather. Stop insulting cats.
Potential Seal-Slapping Problem #3 -- Split Tomato
This, too, is a temporary problem caused by the weather. When the plant is ripening fruit and gets dumped on by a gully washer, it absorbs too much water too quickly and the skin splits. However, the split often heals over, forming a scar, and the tomato is still edible.
What to do: Wait for better weather. Eat ugly tomatoes in the meantime.
Potential Seal-Slapping Problem #4 -- Tomatoes That Won't Ripen
This will drive you crazy. Your tomato plant is just loaded with fruit. You want to eat them so bad. But they won't turn red. Day after day after day, they stubbornly stay green. "They're laughing at me," you think. "They want me to lose my mind."
You are correct. They do. But that's not the only reason they won't turn red. It takes a lot of energy to ripen a heavy crop of fruit. When the plant is stressed by hot weather, it simply can't ripen it as quickly as usual.
What to do: Lighten the load on the plant by picking some green fruit and making fried green tomatoes. This will help the plant ripen the remaining fruit. They'll all ripen eventually, even if you've been institutionalized in the meantime.
Potential Seal-Slapping Problem #5 -- Early Blight
Early blight (Alternaria solani) is the most common fungal disease of tomatoes. It spreads by spores in the soil that rain splashes up onto the lowest set of leaves. Tan spots with purple-brown rings appear. Leaves yellow and die. But before they drop, more rain splashes spores from them onto the leaves next highest up. The disease gradually "climbs" the plant. Leaves and stems shrivel and your plant croaks.
What to do: Plant a tomato selection like 'Celebrity' that resists early blight. This is indicated by the letter "A" after the tomato name on the seed packet. If you don't know whether your tomato is resistant, cover the soil around it with an inch of mulch after planting to bury any spores. Don't wet the foliage when watering. As the plant grows, gradually remove the lowest leaves, until the lowest leaves are a foot off of the ground. (Don't do this, though, for dwarf, patio, or container tomatoes.) If disease shows up, quickly pick off infected leaves and throw them out with the trash. Then spray healthy foliage according to label directions with Natria Disease Control (a biological fungicide) or a copper-based fungicide. At the end of the growing season, remove and throw out all tomato plants. And don't plant tomatoes in the same spot every year.