To avoid a disappointing cucumber crop you have to make sure the female flowers on your plant are being pollinated.
As cucumber plants can’t pollinate themselves, they need the help of pollinators such as bees.
This process usually occurs very easily if enough pollinators are around.
But if not, you’ll have to take care of it yourself.
So how can you tell if a cucumber is pollinated?
In this guide, we show you the signs to look out for. And what you can do to make sure it happens.
Early Signs Of Pollination
There are a few things you can look for to see if your cucumber plant is pollinated.
Firstly, observe how many pollinators are in your garden visiting your plants. Bees and butterflies are common pollinators to look out for.
For example, if you notice a lot of bees visiting the female flowers of your cucumber plants then you can be confident that they’ve been pollinated.
The more visits to a cucumber flower by a pollinator the greater the chance of a pollinated calyx developing into a cucumber. This is because the development of the fruit requires an adequate number of cucumber seeds to be fertilized.
But on its own, this isn’t a clear enough sign. So you should take a closer look at the female flowers.
You’ll notice they have a mini cucumber behind them. This only grows into a full-sized cucumber if the flower is pollinated. Otherwise, the cucumber will shrivel up and die on the vine. So a growing cucumber is confirmation that pollination occurred.
How To Tell If A Cucumber Is Pollinated – 6 Ways
You can tell if a cucumber is pollinated by looking if the male and female flowers of the plant have fallen off, the size of the cucumber growing behind the female flower, the rate of growth, the color, the shape of the blossom end, and the condition of the pistil.
After releasing their pollen to pollinate the female flowers the male flowers shrivel and die. This is followed shortly after pollination by the female flowers, usually within 24 hours.
Some cucumber species flower again after you harvest the cucumbers.
The Female Cucumber Pistil Shrivels and Dies
The female pistil shrivels and dies after pollination as it is no longer needed to receive pollen.
In some cucumber varieties, the pistil changes color after pollination before it dies.
The Size & Shape
A pollinated cucumber will typically start to grow and develop properly. It will exhibit a uniform shape and size that depends on the cucumber variety but is usually green and long.
The Blossom End
Check the blossom end (opposite the stem) of the developing cucumber. If it appears plump and round, the fruit is pollinated. On the other hand, if the blossom end is shriveled or misshapen, it may indicate poor pollination or a lack of female flower pollination altogether.
The Growth Rate
A pollinated cucumber will generally grow at a steady rate. If the growth is stunted or irregular, it may indicate inadequate pollination.
As the cucumber matures, it will generally develop a consistent color typical of the particular variety. However, color alone is not a definitive indicator of successful pollination.
Cucumber Flower Pollination
When making sure you achieve successful pollination of your plants there are some important things to consider.
Cucumbers come in 3 types: monoecious, gynoecious, and parthenocarpic.
Monoecious cucumbers usually produce more male than female flowers. And the male flowers develop earlier, with the female flowers developing in time for pollination.
Gynoecious cucumber plants produce a large number of female flowers. Because they still need to be fertilized, you’ll need to plant some monoecious plants with them if you have this type of plant. Otherwise, pollination won’t occur.
Many seed companies provide blends with 85-90% gynoecious and 10-15% monoecious seeds so you can achieve successful pollination and have the higher fruit yields of gynoecious cucumber plants.
The third type of cucumber is parthenocarpic. These are seedless varieties and produce fruit without needing pollination.
Different cucumber varieties can often cross-pollinate each other.
Some people think that cross-pollination from other cucurbits, such as summer squash plants, can pollinate cucumbers. But this won’t work.
Cucumber Flower Anatomy
The male flowers on monoecious plants contain stamens that produce sticky pollen. The stamen consists of filaments and anthers, with the pollen sticking to the anthers.
For the pollination process to take place the pollen needs to be transferred from the anthers of the male flower to the pistil in the female blossom.
The pistil consists of 3 main parts:
- The stigma—a specially adapted area for receiving pollen.
- The ovary—containing the ovules at the bottom of the blossom.
- The style—which connects the two.
Pollination & Fertilization
Because the pollen produced by male cucumber flowers is sticky, it’s not transferred to female flowers by the wind. Instead, it needs to be carried by pollinators.
When it’s deposited on the stigma of the female flower, it germinates and travels through the style to the ovules.
Once the ovules are fertilized they start to develop. And hormones are released that stimulate the development of the cucumber fruit.
For the proper development of the cucumber to occur there needs to be a sufficient amount of seeds within it that have been fertilized.
Without this, you’re likely to see cucumber growth issues. Sometimes the cucumber is aborted or grows to be deformed.
Hand Pollination Of Cucumber Flowers
If you’re having problems with the pollination of your cucumber plants you can help the process by pollinating the female flowers yourself. Fortunately, hand pollination is easy:
- Get a small paintbrush with soft bristles and swirl it around the center of an open male flower. This will pick up some pollen.
- Then gently brush the pollen onto the center of a female flower.
- Repeat this process to transfer pollen from the male flowers to each female flower on your plant.
Encouraging Natural Pollination
Do you want pollination to take care of itself the natural way?
If you don’t want to hand pollinate the female flowers, here are some things you can do when gardening to attract more pollinators:
- Plant a variety of pollen-rich plants that flower throughout the growing season.
- Stop using pesticides on the plants and flowers in your vegetable garden—they can kill bees and other insects.
- Provide a source of water for pollinators to drink from.
- Create places in your garden for wild bees to nest.
- Allow lawn weeds to grow and flower.