We are at the peak of tomato harvesting and enjoyment time in Maryland. But many gardeners are unhappy, to varying degrees, with the quantity and quality of the fruits of their labor. Those tomatoes we waited so patiently for may have disappointing spots, rots, cracks, and holes.
Before we get into the specific problems, let’s agree that we cannot expect all of our fruits to be perfect, no matter how much time, money, and effort we invest. It’s a garden, not a climate controlled factory. Weather and climate change, soil and sunlight, cultivars and spacing are just some of the many factors affecting plant growth — and they change every year.
This is a good time to think about what we can do next spring to get more out of our tomato plants next year. Picking fruits when they begin to change color from green will increase the number of usable fruits. It allows you to get your fruits off the vine before problems strike. Ripen them indoors on a counter or in a box, basket, or bag. I think you’ll find they taste just as good as their “sun-ripened” sisters.
Common Problems with Tomato Fruits
Problem: Tomato skins thicken and harden as they enlarge and ripen. They crack easily with rapid and large changes in fruit temperature and water availability. Excess nitrogen is another contributing factor. Significant cracking occurs after thunderstorms. Fruits with poor leaf coverage are especially susceptible.
Solution: Water around the base of the plant. Cover the soil with an organic mulch. Pick fruits when they start to turn color.
2. Spots From Stinkbug Feeding
Problem: Several different stinkbugs feed on tomatoes. They feed using piercing-sucking mouthparts and leave behind white to yellow corky spots.
Solution: Stinkbugs are widespread and difficult to handpick and control. Minor damage can be cut out with a sharp knife.
3. Sunken Spots With Rings
Problem: Anthracnose is a fungal disease that affects ripe and over-ripe fruit. Sunken spots enlarge, concentric rings develop, and tan to black spots emerge followed by salmon-colored spores.
Solution: This disease occurs naturally throughout the state and all tomato fruits are susceptible. Prevent the problem by harvesting fruits when they first turn color.
4. Caterpillar Holes
Problem: Caterpillars also like tomatoes! Fruitworms can ruin fruits by feeding all the way to center of your fruits. Luckily, caterpillars are typically not a major problem for tomato gardeners. In many cases they “take a bite” and leave.
Solution: Handpick hornworms and cutworms when you see them. Cut out the damage from minor feeding. Harvest fruits when they start to turn color.
5. Frost is Coming!
Solution: Pick all of your green tomatoes before the first hard frost. Those with a white star on the bottom will eventually ripen indoors. There are lots of wonderful green tomato recipes for the rest. My favorites are fried green tomatoes and green tomato pickles.
By Jon Traunfeld, Director, Home and Garden Information Center