Extension

Shelby Mendoza, Assistant Manager for the OSU Student Farm

As temperatures rise, some gardeners may notice that their cucumbers taste bitter. This bitterness is caused by the compounds called cucurbitacin. Cucurbitacins are produced by cucumber plants as a natural defense mechanism. They are normally found in the stems, roots, and leaves, but they can move into the fruits when plants are under stress. When Oklahoma temperatures become very hot, they can trigger stress in many cucumber plants.

 Image Credit: Shelby Mendoza

To reduce bitterness, you can cut off the end of the cucumber that was attached to the stem and peel the rest of the cucumber because cucurbitacins are most concentrated in the stem end of the fruit, just under the peel. For future plantings, consider growing burpless cucumber varieties. Burpless cucumbers have been bred to produce lower levels of cucurbitacins, making them less likely to develop a bitter flavor. However, even burpless varieties may become slightly bitter if plants experience severe environmental stress, such as prolonged heat or drought.

Another way to reduce the chance of bitter cucumbers during our hot temperatures is to water deeply, providing your plants with 1 to 1 ½ inches of water per week, depending on rainfall and soil conditions. Mulching and keeping your cucumbers weed free also help to retain soil moisture and reduce competition that can stress plants.