We love eating fresh, pickled or cooked cucumbers, but growing them in home gardens is more challenging than 1,2,3. One of the most common problems encountered, even by experienced gardeners, are cucumber plants, which flower but still need to set fruit.
Fortunately, you’re not alone; we’re here to help find the cause of this dilemma and how to solve it. So, read the rest of this article, and you’ll be harvesting cucumbers all season long!
Why do cucumbers flower but produce no fruit?
Cucumbers flower but do not set fruit because of a lack of male or female flowers, pollination, bad weather conditions, improper watering, nutrient imbalance and insufficient sunlight.
Let’s look at how each growing condition prevents cucumber plants from setting fruit and how to fix them.
1. Lack of Female Flowers
How To Fix:
Keep the cucumber plant in a cool area.
Most cucumber plants are monoecious, meaning each possesses male and female flowers. Male and female cucumber blossoms are produced in about equal numbers on monoecious plants, but the problem is that they’re not produced in equal numbers.
Male flowers are usually found on shorter and thinner stems in clusters of three or five and produce pollen but not fruit. They appear first on the plant before female flowers bloom.
On the other hand, female flowers are found on longer, thicker stems. They do not produce pollen but only small swollen fruits behind the flower that will later grow into cucumbers.
Female flowers come later in the season after males have bloomed to secure enough pollen for the female flowers when they arrive later. The environment, genetics or imbalanced nutrition usually cause the lack of female flowers.
Since male flowers appear earlier, the common problem is that the female blossoms have yet to form. Without them, cucumber plants cannot produce fruit, and the pollen from male flowers would have nowhere to go.
Solution: Keep the cucumber plant in a cool area.
| Difficulty | Easy ●○○○○ |
| Speed | Slow acting |
| Things You Need | Cool area for your cucumber plant Greenhouse Shade cloth Watering can |
Cucumber plants produce female flowers when placed in cooler temperatures. So, choose a spot in your garden that gets plenty of sunlight.
During the hottest part of the day, you can move your cucumber plant to a cooler spot, your greenhouse or using a shade cloth. Don’t forget to water your cucumber plant regularly, especially during hot weather.
2. Lack of Male Flowers
How To Fix:
Increase the temperature around the cucumber plant.
The lack of male flowers also causes a lack of fruit in cucumber plants. It most likely happens with gynoecious cucumber varieties or those that produce mostly female and very few male flowers.
Although gynoecious cucumbers produce more female flowers, which means they have more potential to produce fruits, the downside is that they will need nearby plants with male flowers to help pollinate their flowers and produce fruit.
Solution: Increase the temperature around the cucumber plant.
| Difficulty | Easy ●○○○○ |
| Speed | Slow-acting |
| Things You Need | Greenhouse Hotbed Sunny area Glass or plastic |
Warmer temperatures encourage cucumber plants to produce more male flowers. Compared with female flowers, they require less energy for their formation.
It’s best to place your cucumber plant in a sunny garden. They prefer temperatures between 70 and 85 degrees Fahrenheit (21 and 29 degrees Celsius).
You can also grow your cucumbers in a greenhouse or hotbeds. During the day, you can increase the temperature around your cucumber plant by covering it with glass or plastic.
Still, constantly water your cucumber plant regularly, especially during the hottest day.
3. Lack of Pollination
How To Fix:
Option 1: Hand-pollinate cucumber flowers.
Option 2: Attract pollinators in your garden.
Although they both have male and female flowers, cucumber plants are not self-pollinating. They still need pollinators like bees and butterflies to carry the pollen from male to female flowers.
So, conversely, without proper pollination, your cucumber might have flowers, but it will not set fruit. This is the time to call pollinators into action.
Bees are the most common rescuers for this problem. They carry pollen from male flowers to female flowers on cucumber plants. There are also butterflies and other beneficial insects that help get the job done and kickstart fruit development.
Option 1: Hand-pollinate cucumber flowers.
| Difficulty | Easy ●○○○○ |
| Speed | Fast-acting |
| Things You Need | Soft-bristled brush (paintbrush or toothbrush) Cotton swab |
Hand pollination is the fastest way to ensure pollination of female cucumber flowers. When the pollen fertilizes the ovules of the female flowers, it triggers the development of fruits.
The best time to hand pollinate this plant is in the morning because the flowers are usually open by then. Always look for the newest male flowers in your cucumber plant to increase the chances of successful hand pollination.
How To Do
1. Identify the male and female flowers.
2. Male flowers are small on the long, thin stems, while female flowers are small with swollen ovaries at their base.
3. Open a male flower and gently brush the pollen onto the brush.
4. Open a female flower and dab the pollen onto the stigma, the sticky part in the center of the flower.
5. Repeat these steps for each female flower you want to pollinate in your cucumber plant.
Option 2: Attract pollinators in your garden.
| Difficulty | Easy ●○○○○ |
| Speed | Fast-acting |
| Things You Need | Flowering and native plants Shallow dish or birdbath |
Go natural by attracting pollinators in your garden. You can do this by planting flowering plants or native species or providing water sources to entice these beneficial animals.
When choosing flowering plants, go for plants with different colors, shapes, and bloom times to have a continuous source of nectar and pollen in your garden. We recommend pollinator-friendly plants like sunflowers, zinnias, lavender, and calendula.
You can also create a habitat for beneficial insects, like nesting sites, bee hotels or butterfly houses, to entice them to stay in your garden. To attract ground-nesting bees, you can keep some areas undisturbed with bare soil or leaf litter.
These pollinators also need water to survive, so placing a shallow dish or birdbath in your garden will give them access to water, especially during hot weather, and increase their chances of pollinating your cucumber flowers.
Finally, we suggest you avoid using harmful pesticides because they harm these pollinators. Opt for natural pest control methods like using neem oil, insecticidal soap or adding ladybugs to eradicate them without harming these beneficial insects.
4. Bad Weather Conditions
How To Fix:
Protect the cucumber plant from extreme weather.
Temperature is an essential factor in flower and fruit formation in cucumber plants. When the temperature hits below 50 degrees Fahrenheit (10 degrees Celsius), it will cause slow growth and damage the cucumber plant.
When it’s too hot, a cucumber plant produces more male flowers; conversely, a cool temperature encourages the formation of more female flowers. On the other hand, rainy weather may stop bees from pollinating flowers and less fruit.
Cucumber variety also affects how each plant will respond to different temperatures and how long it will take to form flowers. Vining cucumbers produce more fruit, while bush varieties produce less every growing season.
Solution: Protect the cucumber plant from extreme weather.
| Difficulty | Average ●○○○○ |
| Speed | Slow-acting |
| Things You Need | Shade cloth Row covers Frost blankets Mulch Organic matter |
Cucumbers are sensitive to cold temperatures, and frost can cause damage to the plant, such as disrupting their fruit production.
Protect your plants during hot or cold weather by providing shade using row cover, shade cloth or frost blankets or moving them indoors during cold nights. This is how you can make sure they won’t get stressed by the extreme weather conditions.
You should also add organic matter to improve soil drainage and mulch around the base of the plant to retain soil moisture. It’s an effective way of maintaining the required temperature for cucumber plants and preventing the spread of fungal diseases.
5. Improper Watering
How To Fix:
Practice drip irrigation.
Cucumber plants need at least one inch of water every week. They need water to uptake and transport essential nutrients from the soil to different plant parts to ensure their growth and development, including fruit production.
Water maintains the turgidity of plant cells, which helps the plant maintain its structure and overall health. In cucumbers, maintaining cell turgidity is essential for the development of fruits, or else it will lead to wilting flowers and developing fruits.
Cucumber plants are susceptible to fluctuations in moisture levels, so improper and irregular watering will lead to poor fruit production.
Whether over or under water, you’ll stress your plants, leading to an increased risk of root rot, reduced pollination and inevitably, lack of fruits throughout the growing season.
Solution: Practice drip irrigation.
| Difficulty | Average ●●●○○ |
| Speed | Slow-acting |
| Things You Need | Water source Main line Lateral lines T-connectors Stakes Timer Mulch |
Drip irrigation is an efficient way to water plants because it delivers water directly to the root zone and reduces water waste or runoff. It also helps promote deep-root growth and reduces the risk of fungal diseases.
Cucumber plants grow best under a consistent watering schedule where they get at least one inch per week. You can adjust this amount depending on the weather conditions, such as increasing watering during hot, dry periods.
How To Do
1. Choose a water source, such as a faucet, rainwater barrel, or irrigation pump.
2. Lay out the main line or the pipe that will carry water from the source to the lateral lines.
3. Place the main line along the rows of cucumber plants.
4. Attach the lateral lines or the pipes that will run alongside each cucumber plant to the main line using T-connectors.
5. Place the emitters or devices that release water slowly and steadily next to each cucumber plant.
6. Space them evenly along the lateral lines.
7. Stake the lateral lines in place to prevent the lines from moving around.
8. Connect the main line to the water source.
9. Turn on the water and set the timer to water the cucumber plants for 1-2 hours daily.
10. Apply mulch around the cucumber plants to moisten the soil and reduce evaporation.
6. Nutrient Imbalance
How To Fix:
Identify the nutrient deficiency and apply the right fertilizer.
Cucumber plants are heavy feeders, especially with nitrogen, but as with everything, moderation is key. Too much nitrogen in the soil can burn plants and delay flower production in cucumbers.
Heavy nitrogen content in the soil leads to cucumber plants in a vegetative state for a long period, which leads to an imbalance where they grow their stems and leaves longer, leaving less energy to produce little or no flowers later in the season.
Solution: Identify the nutrient deficiency and apply the right fertilizer.
| Difficulty | Average ●○○○○ |
| Speed | Slow-acting |
| Things You Need | Soil test Fertilizer |
Soil pH plays a crucial role in nutrient absorption by cucumber plants. A near-neutral pH, typically between 6.0 and 7.0, is ideal for cucumbers since it allows for optimal nutrient availability and absorption by the plant roots.
On the other hand, soil that’s too acidic or alkaline can limit the availability of certain nutrients, leading to poor fruit production. So, the best way is to conduct a soil test to determine pH and nutrient levels and add the missing fertilizer to your garden soil.
Here’s a summary of what to apply for every nutrient deficiency.
| Nutrient Deficiency | Symptom | Treatment |
| Nitrogen | Yellow leaves Stunted growth Delayed or lack of flowers | Nitrogen-rich fertilizer Ammonium sulfate Urea |
| Phosphorus | Purple leaves Slow growth | Phosphorus-rich fertlizer Superphosphate Bone meal |
| Potassium | Brown leaf margins Curling leaves | Potassium-rich fertilizer Potassium chloride Potassium sulfate |
| Calcium | Blossom end rot Weak stems | Calcium fertilizer Calcium nitrate Calcium sulfate |
| Magnesium | Yellow leaves with green veins Interveinal chlorosis | Magnesium-rich fertilizer Epsom salt Magnesium sulfate |
7. Insufficient Sunlight
How To Fix:
Move the cucumber plant to a sunnier location.
Cucumbers need at least six hours of sun per day to produce fruit. Insufficient sunlight causes cucumber plants to flower but not produce fruit because they don’t have the energy to produce fruits.
When they don’t receive enough sunlight, cucumber plants suffer from stunted growth and weak stems and may not produce fruit in the growing season.
Solution: Move the cucumber plant to a sunnier location.
| Difficulty | Average ●○○○○ |
| Speed | Slow-acting |
| Things You Need | Sunny spot Watering can Shovel Mulch |
Cucumber plants need at least 6 hours of direct sunlight daily; otherwise, they will not produce fruit. So, if you haven’t planted your cucumber yet, choose a spot in your garden that gets the required sunlight daily.
If the plants are already planted in the ground, you can carefully dig them and transplant them to the new location. Make sure to dig a hole large enough to accommodate the root ball and fill the gap with loose, well-drained soil.
If the plants are planted in containers, you can simply move the containers to the new location. Avoid moving the plants on a hot day; move the plants on a cloudy day or evening.
Just constantly water the plants well after transplanting them to prevent transplant shock. You can even add mulch around the base of the plants to help keep the roots cool and moist.
What is the cucumber flowering and fruit production process?
Cucumber plants will produce buds of male and female flowers. Once these flowers open, animal pollinators or hand pollination will transfer the pollen from the male flower to the female flower and begin fruit development.
Cucumber plants produce male and female flowers. Male flowers usually appear first, followed by female flowers.
Female flowers have a small, immature cucumber ovary at the base of the flower, while male flowers have a thin stem. Then comes the pollinators like bees and butterflies, which transfer pollen from male and female cucumber flowers.
After successfully pollinating the female flower, the cucumber plant’s fruit production process will begin. As long as the plant is in a warm, sunny area with consistent moisture and well-drained soil, it will produce fruits in no time.
Cucumber Varieties
Cucumber varieties also affect their fruiting process. The most common types of cucumbers are monoecious, gynoecious, and parthenocarpic varieties.
Monoecious plants produce both male and female flowers, while gynoecious plants produce primarily female flowers. Monoecious varieties produce more fruits because they already have reproductive plant parts than gynoecious cucumbers.
Monoecious cucumbers include the Burpee Hybrid, Spacemaster 80 and Homemade Pickles, while gynoecious cucumbers include Sweet Success, Mini Much and Beit Alpha varieties.
There are also parthenocarpic cucumbers, which can produce fruit without pollination.
This variety is commonly used by gardeners struggling to attract pollinators or grow cucumbers in greenhouses.
Some parthenocarpic cucumbers are H-19 Little Leaf, Iznik and Excelsior cucumber varieties.
What are good companion plants for cucumbers?
Here’s a table of the best companion plants for cucumbers and their benefits.
| Companion Plant | Benefits |
| Beans and peas | Add nitrogen to the soil Act as natural trellises for cucumber vines Improve air circulation |
| Radishes | Deter pests like cucumber beetles Help improve soil drainage and aeration |
| Marigolds | Repel pests like nematodes and whiteflies Attract beneficial insects like pollinators and predatory insects |
| Nasturtiums | Repel pests like aphids Attract beneficial insects like pollinators and predatory insects |
On the other hand, here are plants that are not recommended to be planted near cucumbers:
| Plant | Negative effects |
| Potatoes | Compete with cucumbers for nutrients and water Susceptible to the same diseases, such as blight |
| Melons | Can encourage the spread of pests and diseases that affect both plants Can compete for nutrients, water, and sunlight |
| Aromatic herbs like sage and mint | Can inhibit the growth of cucumbers Repel pollinators |
FAQs on Cucumber Flowering But No Fruit
After pollination, small cucumbers will take four to five days to mature, while large varieties take eight to ten days. On the other hand, slicing cucumbers takes 15 to 18 days to mature.
Cucumber plants set fruit within five to ten days after flowering. However, if the weather is too cold or without pollinators, it may take longer for the cucumber fruit to set.
Cucumber plants need a balanced nitrogen, phosphorus, and potassium fertilizer. You can also make fertilizer by mixing compost, manure, and bone meal.
You should not remove the cucumber flowers because this will prevent the plant from producing fruit.
A cucumber flower is pollinated when the stigma, the sticky part in the center of the flower, is swollen and brown.
You should cut off dying cucumber leaves because they can harbor pests and diseases and block sunlight from reaching the healthy leaves.
