Have you ever gone out to the garden, and found a ripening tomato that gets your mouth watering, only to find that it is cracked or split open? The first reaction could be disappointment, followed by anger. Your mind flashes through possible scenarios that involve animal pests, insect pests, or maybe some agitating neighborhood kid that has sabotaged your great looking tomato. Actually, none of these are the culprit of your tomato vandalism. What is causing splitting and deep cracks on top of my tomatoes? We call these growth cracks.
Splitting or cracking can be quite common and is brought about by fluctuations in watering. Tomatoes crack when certain environmental conditions encourage rapid growth during ripening. Rapid growth is frequently promoted by a drought followed by heavy rain or watering. Cracking is more severe in hot weather. Tomatoes are most susceptible to cracking after they have reached full size and they begin to change color. When tomatoes begin to ripen during a spell without water, the outer skin will thicken and toughen up. A sudden influx of water will cause the tomato to swell (or continue growing) on the inside. This inner swelling will then cause the thickened outer skin to rupture resulting in a split or crack. Although some minor cracking at the top of the tomato is generally harmless, large splits that expose the tomato flesh can allow decay organisms to enter the fruit and rot it. Plus deep cracks invite insect pests. Shallow cracks frequently heal over, but may rupture again if the fruit is roughly handled when picked. Cracked tomatoes are still edible. What can you do to prevent this tomato cracking?
Succulent plants that are high in nitrogen and low in potassium are more susceptible to cracking. If you have put on a lot of nitrogen the tomato plant could look great, green and lush and growing like kudzu; but it could be too succulent. A good fertilizer program will avoid overly succulent plants.
Proper water management: do not over irrigate plants. One of the most crucial parts of their care is knowing how much water do tomato plants need. The number 1 rule of watering tomatoes is to make sure that you go slow and easy. Never rush watering tomato plants. Use a drip hose or other forms of drip irrigation to deliver water to your tomato plants slowly. How often should you water tomato plants? There is no hard and fast rule to this. It depends on how hot it is and if the plant is actively growing. A good rule of thumb is to supply water once every 2 – 3 days at the height of summer. Remember that water supplied by Mother Nature counts towards watering tomato plants in the garden. Once the weather cools and fruit has set, scale back watering to once a week. When watering tomatoes, make sure you get the water straight to the roots. Do not water from above as this can cause disease and pests to attack the plants. Watering tomato plants from above also encourages premature evaporation and unnecessarily wastes water.
Mulching the area around the tomatoes will help maintain ground moisture levels.
There are only two things that money can’t buy and that’s true love and homegrown tomatoes.
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Brenda Larson is the Horticulture Agent for North Carolina Cooperative Extension in Lee County