Why Does My Cucumber Plant Only Have Female Flowers?

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I don’t know about you, but my favorite summer crop is cucumbers. Their crisp bite and cooling, juicy flesh make it my top snack during the hot season. Of course, nothing beats growing your cucumbers, but what happens when your cucumber plant only produces female flowers? This can become a confusing (and annoying) issue for even intermediate gardeners. In this article, we’re going to take a look at what causes this phenomenon and how to remedy it so you, too, can have a bounty of cucumbers all summer long.

Cucumbers: Scientific Background

The Cucumis sativus, otherwise known as the cucumber, is a member of the cucurbit family. Other members of this group include watermelons, squash, and zucchini. Cucumbers have two separate male and female flowers on each plant (with some exceptions). The female flower produces the actual cucumber fruit that develops on the vine. The male flower’s pollen must be delivered to the female flower (either via bees or gardeners) so that the cucumber grows into a fully formed, edible fruit. 

There are three varieties of cucumbers separated by how they’re pollinated. The first group is the “standard” or “monoecious.” These are cucumber plants that grow both male and female flowers. The first 10 to 20 flowers produced on these plants are male. After the initial group of male flowers, 10 to 20 extra male flowers grow for every female flower that grows. These plants can pollinate themselves with the assistance of a pollinator. 

The second group is called “gynoecious.” Gynoecious cucumber plants primarily grow female flowers only. As a result, these plants develop fruit a little earlier than standard cucumber varieties. To ensure that the female flowers are pollinated, gynoecious plants are accompanied by a separate monoecious plant whose male flowers are used to pollinate the female flowers.

The third group is “parthenocarpic” plants. On these plants, all flowers are entirely female. The fruits produced from this plant are completely seedless; they manage to grow fruit with no pollination. Growing a parthenocarpic cucumber plant takes extreme diligence and care. These plants must be bred separately because any cross-pollination with a standard plant will cause the parthenocarpic fruits to grow seeds. Purchasing seeds to grow a parthenocarpic plant from scratch is quite pricey.

Identifying your Cucumber Flowers

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Now that we’ve gotten the pleasantries out of the way, it’s time to identify your cucumber. If you think your cucumber is exclusively producing female flowers, then you may have inadvertently grown a gynoecious cucumber plant. The easiest fix to this is finding a separate standard cucumber plant and using the pollen from their male flowers to pollinate your female flowers.

If you have a friend who also owns a cucumber plant, ask them if they’ll lend you some of their male flowers. Otherwise, you can grow a second plant; the more, the merrier! To ensure that the pollen is being delivered straight to the female flowers of your gynoecious plant, you can hand-pollinate your cucumbers on your own.

Hand Pollinating Cucumbers

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Usually, pollination is left up to pollinator insects such as bees. However, to be 100% certain every female flower on your plant is pollinated, you can take nature into your own hands! Hand pollinating plants might sound intimidating, but it’s simple and easy to do! Many seasoned gardeners prefer to hand pollinate because it ensures that their future fruit is being delivered a healthy dose of pollen, leading to healthy, tasty yields of cucumbers (or any crop).

Take a small-bristled paintbrush (a Q-tip also works well in a pinch). This paintbrush should be completely clean and sterile, fresh from the package. Then, identify a male flower. The male flowers are the ones that don’t look like they have a tiny cucumber attached to them. Next, gently tap the paintbrush into the center of the flower; you should be able to see the vibrant orange pollen at the end of the brush.

Be careful not to accidentally shake off the pollen from the brush before getting it over to the female flower. Instead, find a female flower and gently rub the pollen right in the center. Keep repeating until all female flowers have been pollinated. You can pollinate multiple female flowers with just one male flower, so don’t be discouraged if you have an uneven ratio of male to female flowers.

Hand pollination can be tedious, but it guarantees that your female flowers are pollinated. Putting in this extra effort will yield tremendous rewards.

Tips for Growing Amazing Cucumbers

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So we’ve fixed the dilemma of pollinating a gynoecious cucumber plant, but we’re not entirely out of the woods yet. Pollinating your flowers is only one step towards growing delicious cucumbers. Follow these helpful tips for the most excellent cucumber harvest you’ve ever had !

Test your soil to ensure the pH level is ideal for your cucumbers. Aim for a neutral to slightly acidic; around 6.5 to 7.0 is best. Amending your soil with aluminum sulfate can acidify the ground if your pH level is too high. On the flip side, adding limestone to the earth that is too acidic can raise the pH level, making your soil more alkaline.

If you have a vining variety of cucumbers, I highly recommend adding a trellis to your garden so your cucumbers can climb. Doing so can not only help you save space in your garden, but it prevents your cucumbers from dragging on the soil.

If you have a vining variety of cucumbers, I highly recommend adding a trellis to your garden so your cucumbers can climb. Doing so can not only help you save space in your garden, but it prevents your cucumbers from dragging on the soil.

Water your cucumber plant deeply; they regularly require a healthy dose of watering. However, avoid getting the leaves wet, as moistened leaves can introduce diseases that destroy the whole plant. Instead, give your plants a slow stream of water directly at the base; this should be done during the morning or early afternoon. 

Cucumbers love to grow in warm climates (they’re native to South Asia, after all). So if you’re growing cucumbers and you’re worried they might be too cold, you can spread mulch around the base of your plants. Mulching has many benefits besides regulating soil temperature; they also retain moisture and prevent your roots from drying out too quickly, and deter pests from attacking your cucumber plant, from naming a few.

Don’t let your cucumbers grow to be too big; bigger is not always better when it comes to your harvest! Leaving your cucumbers on the vine for too long can cause them to become yellow in color and monstrous in size. In addition, overgrown cucumbers become more bitter, and the skin can become inedibly tough. For maximum flavor payoff, harvest your cucumbers when they’re slightly immature, uniformly green in color, with a firm texture. 

Keep picking your cucumbers as soon as they’re ready; make sure you use a sharp knife or pair of clippers to cut the cucumbers from the vine. Leaving your cucumbers to sit on the vine discourages production & productivity. To have a consistent and bountiful harvest, you have to keep picking cucumbers.

In Conclusion

Nothing is more frustrating than when your cucumber plants just aren’t producing cucumbers. For gardeners whose cucumber plant only grows female flowers, it can be frustrating. Luckily, you’re not alone; this is a problem that can affect even experienced gardeners. Now that you have the proper knowledge to approach this situation, I’m sure you’ll be growing the best cucumbers you’ve ever grown from now on.


Works Cited

Badgett, Becca. “Cucumber Plant Pollination – How to Pollinate Cucumber By Hand.” Gardening Know-How. https://www.gardeningknowhow.com/edible/vegetables/cucumber/hand-pollinating-cucumbers.htm

The Editors. “Cucumbers: Planting, Growing, and Harvesting Cucumbers.” The Old Farmer’s Almanac. https://www.almanac.com/plant/cucumbers#

“Understanding Flowering Habits in Cucumbers.” Agronomic Spotlight. https://www.vegetables.bayer.com/content/dam/bayer-vegetables/english/united-states-canada/product-sheets-and-pdfs/agronomic-spotlights/Understanding-Flowering-Habits-in-Cucumbers-Seminis.pdf