Tomatoes! They’re not only tasty, but they’re also loaded with vitamins A and C, calcium and lycopene, a substance believed to help prevent cancer. And they’re as easy to grow as dandelions. Not bad for a fruit once shunned as being poisonous. Fortunately for us, that belief went out with muskets.
But there still are some perpetual cultural and chemical problems these savory summer favorites can encounter in the garden. Here’s a look at four tomato problems and how to deal with them.
This unusual condition happens when the tomato flowers don’t develop properly. It’s usually caused by low nighttime temperatures, below 55 degrees, or strong winds. If you’re expecting a cold night or high winds, shelter plants temporarily by covering them with a plastic tarp.
Splitting and cracking in the skin of the fruit is caused by fluctuations in water content, which comes from inconsistent soil moisture. A sudden, large water uptake by the plant, such as when it rains after a dry spell, makes the tomato skin split open as the fruit quickly absorbs the water. Avoid splitting by mulching the plants and giving them 1 to 1 1/2 inches of water per week throughout the growing season. Irrigate early in the day and avoid wetting the foliage. Soil-borne fungi are easily transmitted to wet leaves. Never let the soil completely dry out.
When the bottom of a tomato blackens into a sunken, ugly, leathery spot, you’re looking at blossom-end rot. The cell tissue of the tomato becomes soft and easily damaged. It’s caused by a lack of calcium, which the fruit needs to strengthen these cells. But lack of calcium can be caused by a couple of different things. One is lack of water, which prevents the plant from taking in calcium. The other is a soil pH over 7 or below 6.5. These chemical conditions prevent calcium from moving from the soil into the roots of the plant. Keep the plants consistently and evenly watered, and strive for a soil pH in the range of 6.5 to 7.
The tomatoes remain hard, green and unripened around the stalk. This is usually caused by a lack of potassium in the soil. Keep an eye on the plant’s foliage as the fruit is developing. Potassium deficiency causes leaves to lose color between the veins and scorch at the edges. These scorched edges turn up and inward, toward the upper surface of the leaf. Feed the plants every 2 to 3 weeks with high-potassium, fish emulsion fertilizer according to package directions.