Unusual Vegetable Problems

Rotting zucchini fruit can be caused by disease, but it is more likely to be caused by poor pollination.

By Charlie Nardozzie

Summertime in the vegetable garden can mean problems, especially with insects and diseases. While there are many insects and diseases that attack vegetables, some problems may not be related to pests at all. Some vegetable problems are abiotic, which means they are caused by a nonliving agent. The solution isn't reaching for the sprayer, but being creative about solving the problem. Here are two abiotic problems to watch for in the garden.

Blossom End Rot

This tomato problem is widespread. The blossom end of tomato fruits rot as the fruits mature. This is most evident on elongated-shaped tomato varieties, such as 'San Marzano', but I've seen it on most large-fruited varieties, too. While the temptation is to think a disease is causing the problem, the problem is actually related to water. When the the soil around the tomato gets alternately saturated and dried out a number of times, the tomato plant becomes calcium deficient. The resulting calcium deficiency manifests as a rotting of the blossom end of fruits. The solution is to mulch around the tomato and keep the soil consistently moist. While this won't help the existing rotten fruits, it will prevent the problem from occurring on the new fruits.

Zucchini Fruits Rotting

Usually zucchini and summer squash produce more fruits than you can eat. However, sometimes you'll get squash fruits looking fine, but rotting before they start to grow. While there are diseases that can cause this problem, the more likely culprit is poor pollination. Summer squash have male and female flowers. The female flowers have small squash behind them. When proper pollination occurs, the squash fruits expand. However, if bees aren't flying due to cloudy weather or there aren't many bees in your area, pollination doesn't occur and the squash fruits rot instead of grow. The solution is to cross-pollinate the fruits yourself with a cotton swab. In the morning, take the pollen from a male flower (no fruit behind the flower) and transfer it to a female one. That should fix the problem.