Why Are My Cucumbers Bitter?

“I am growing the same cucumbers this year as last year.  Every cucumber this year looks beautiful but tastes very bitter and is inedible.  I believe I am providing adequate water, though due to the heat the plants still wilt during the day. What can I do to improve the flavor? ” Lisa of Marietta, Pennsylvania

Answer: There are two things that can cause cucumbers to become bitter – the cultivated variety and environmental stress (heat stress, water stress, or disease). A great Oregon State University (OSU) article on the subject quotes the vegetable breeder, Jim Myers of OSU. He explains that the source of cucumber bitterness is caused by the natural plant chemical, cucurbitacin. It exists in high quantities in the leaves and stems of cultivated cucumbers. During stressful summers, concentrations can build up at different levels in the cucumber fruits as well; often at the blossom end. What’s odd is that sometimes a single plant may have some bitter fruits and some nice-tasting cucumbers, so taste each one to double-check before composting. The same plant may also produce sweeter fruits as growing conditions become better.

Non-Bitter Cucumber Varieties

Some varieties tend to reliably produce sweet cucumbers, even under stress. Here are five excellent cucumbers that resist bitterness.

  1. Katrina‘- The crisp, seedless, Beit-Alpha-type cucumber is also very disease-resistant and stays sweet.
  2. ‘Jibai Shimoshirazu’ – This heat-tolerant, Japanese snacking cucumber never gets bitter!
  3. ‘Green Light‘ – There is a reason that this cucumber was a 2020 All-America Selections winner. Its fruits are crisp, sweet, prolific, and resist bitterness.
  4. Marketmore 97– This classic, disease-resistant cucumber is known for its ability to stay sweet, even when stressed.
  5. ‘Unagi’ – After reading about this one, I plan to grow it next year. Its hybrid cucumbers are crisp, sweet, and very prolific.

I also recommend that you watch the video below to learn how to grow cucumbers to perfection. I know that it can be difficult in years where high heat, drought, and even excess rain are problems, but the video contains some good growing tips.

Happy gardening,

Jessie Keith

Black Gold Horticulturist

Recipe: Fresh Herbed Cucumber Cocktails

Cucumber Cocktail refreshing-300x300

Nothing is more refreshing in summer than a delicious cocktail made with crisp cucumbers and aromatic herbs harvested straight from your garden. These drinks contain fresh rosemary and basil, though you can also replace them with fresh mint, if you like. Whip up one of these delicious summer cocktails, and let your party stand above the rest.

Cucumber & Basil Mojito

2 sprigs fresh basil leaves
2 slices cucumber
1 lime, quartered
1 tablespoon raw cane sugar
1 shot white rum
4 ounces club soda
Crushed ice
Makes 1 serving

In a tall, sturdy cocktail glass, add the fresh basil leaves and raw cane sugar. Macerate the sugar and mint together at the bottom of the glass with a wooden spoon and then squeeze in the lime. Add the rum, cucumber slices, and let the mix sit for 5 minutes before adding the ice, club soda, mixing. Finish the drink with a slice of cucumber and fresh basil sprig.


Cucumber & Rosemary Lemonade Chiller

1 cup fresh cucumber slices
2 sprigs fresh rosemary
4 cups water
5 shots ounces vodka
1 cup fresh lemon juice (juice of approximately 5-6 large lemons)
1/2 cup superfine sugar
1 cup crushed ice
Makes 5 servings

Place the superfine sugar, lemon juice, and vodka in a glass pitcher, and mix until the sugar has dissolved. Add the cucumber and rosemary and allow the flavors to marry for 20 minutes. Add the water, ice, and mix well before serving. Finish each drink with a sprig of rosemary and a lemon slice.