Homegrown tomatoes are typically better than store-bought. But sometimes things go awry just when you’re looking forward to that wonderful flavor. How to diagnose and address four common tomato woes…

Splitting fruit. The cause? Inconsistent watering. Soak your plant roots thoroughly every few days (more often in hot, dry spells). Either run the hose at a trickle for a while or use soaker hoses. Apply an inch or two of mulch (straw is ideal) around your plants.

Small cherry tomatoes often split despite your best efforts. This is a case of the flesh outgrowing the thin skin. If it bothers you, pick them early.

Yellow or whitish blotches. This is most likely due to sunscald. Insufficient coverage from the leaves often is to blame. Not only does it mar the look of the fruit, it spoils the flavor.

Tomato leaves dry and drop off when weather is hot and you’ve neglected ­watering. To prevent this, follow the watering recommendations above.

Pests and disease also cause leaf loss, which can lead to sunscald. Tomato hornworms—green caterpillars with a hornlike tail—can strip a plant. Keep a lookout, and the moment they appear, handpick them, then drop the worms into a bucket of soapy water. Soil nematodes (root-­infesting worms), tiny flea beetles and various fungal diseases can damage leaves. In the future, look for resistant plants labeled VFNT (for verticillium wilt, fusarium wilt, nematodes, tobacco ­mosaic virus).

When tomato leaves become dried or tattered, remove them. They aren’t going to recover. Dispose of them in the trash, not the compost pile, which won’t get hot enough to kill pathogens or pests. You can then try to rescue tomatoes on already partially defoliated plants by providing shade, such as a strategically placed board, tarp or lawn chair.

Puckering at the blossom end. This is called catfacing, and the tomato may go on to develop crevices, holes and scars. This malady usually is caused by cold weather. High nitrogen levels in the soil also can cause it.

Avoid it by waiting to plant your seedlings until danger of frost is past. If an unseasonable cold spell is predicted, protect plants with cloches (bell-shaped clear glass or plastic covers) or row ­covers—available wherever gardening supplies are sold.

If you suspect high nitrogen, don’t grow tomatoes near grass if you use high-nitrogen lawn fertilizer, or you can withhold plant food in the vegetable garden until fruit starts to form.

Disappointingly small crop. The most and best tomatoes are produced when daytime temperatures are in the 80s and drop to the 50s or 60s at night. If your summer is hotter or cooler, quality can suffer and the plants may produce less. Dry soil, too, discourages fruit set. See watering instructions above. Insufficient sunshine is a problem as well—­tomato plants produce plentiful crops when they receive eight hours of sun a day.

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