Sunny golden cucumber flowers are a surefire sign of summer and crunchy, juicy cukes are just around the corner. But it’s happened to me- my plants aren’t producing as many flowers as I hoped, leaving me wondering what kind of crop I might end up with. Thankfully, I found out there were quite a few things I could do to get my plants to produce more flowers and therefore, yummy fruit.
Cucumber flowers are essential for the plant to produce fruit. The flowers are either male or female; Males produce pollen and females contain immature fruits. Pollen needs to be transferred from the male flowers to the females, where the DNA of both flowers combines to produce a mature fruit. Ways to increase the number of flowers on cucumber plants include proper garden spacing, consistent watering, managing pests and keeping weeds to a minimum.
In this article, I’m sharing what I’ve learned about cucumber flowers and how they work, along with tips for getting your plants to produce the most healthy blossoms possible.
Let’s jump in!
- Most cucumbers produce male and female flowers. Males produce pollen and females are the ones that produce fruit. Male flowers typically appear about 10-14 days before females.
- Cucumbers come in three main types: Monoecious (plants produce both male and female flowers), gynoecious (plants produce female flowers only but still need pollen from male flowers), and parthenocarpic (plants produce only female flowers with seedless fruit- no pollination needed).
- Ways to increase cucumber flowering include plenty of sun exposure, adequate space between plants, consistent watering, regular fertilizing, and pest/disease management.
- To prevent flowers from dropping, maintain good soil moisture, ensure good levels of phosphorus and potassium, and hand pollination.
Why Cucumber Plants Produce Flowers
Cucumbers go through various stages of development on their way from seed to fruit, and flowering is one of those steps.
Cucumbers are members of the cucurbit family, and some close relatives include melons, pumpkins and squash. All these plants produce lovely yellow flowers that contain DNA for producing the next generation of seeds, found inside tasty, juicy fruits.
But not all cucumber flowers are the same- reproduction takes DNA from both a male source and a female source (in most cases- more on that later).
Male and Female Cucumber Flowers: Why They Matter
Most cucumber plants produce both male and female flowers, and it’s easy to tell the difference between them when you know what to look for.
Female flowers are where the actual fruit production happens.
Males have a short stem, and they have a fuzzy, powder-covered stamen- that’s the structure in the center of the blossom that contains pollen.
Here’s a side view of a male flower that shows the short, thin stem:
Female cucumber flowers have a long, thin structure at the blossom base- this is an immature cucumber. The females also have a rounded structure, called a stigma, in the center that receives the pollen.
In this picture, you can see the prickly immature cucumber fruit at the flower base:
Male flowers are the first to appear on the plant, typically showing up 10-14 days before the first female blooms. This is on purpose- the males contain the pollen the females need to develop fruits, and pollinating insects are the transport vessels between the two. Having the male flowers bloom first gets the pollinators in the habit of visiting the cucumber plant daily, so when the females blossom, there’s a better chance for pollination to occur.
Once the pollination process occurs, the plant has all the DNA it needs to produce a cucumber fruit full of seeds.
As you can see, how many flowers you have directly relates to how many cucumbers each plant can produce. So our goal is to have healthy, vibrant flowers if we want a good harvest!
3 Types of Cucumber Flower Production
There are three types of cucumber plants, and the flowering/pollination processes are different for each one:
You might see seeds or seedlings with these labels, so it’s important to know what they mean and how they affect you.
These are the classic cucumber varieties that we’re all likely most familiar with, including all the beloved heirlooms. Monoecious plants produce both male and female flowers, and they rely on pollinating insects or hand pollination by us gardeners to produce fruits.
In my opinion, monoecious cucumbers are the best bet for most home gardeners, and they’re definitely the most common. The plants produce fruits throughout the growing season, letting pick and enjoy fresh cucumbers all summer long.
Plus, I personally prefer to grow heirloom plants whenever possible. I think that we, as home gardeners, have so much freedom, and even responsibility, to keep these old faithful varieties going in these small plots we call our own.
Gynoecious cucumbers are hybrids that produce only female flowers. They typically yield a large harvest of uniform fruits, and all the flowers produce a crop at roughly the same time. For these reasons, gynoecious varieties are very common in commercial farms.
Some gynoecious varieties self-pollinate, meaning that the flowers already contain all the DNA they need to produce fruit. However, most varieties still need pollen from a male flower. In these cases, you’ll need to have a monoecious plant nearby.
Some seed companies include a couple of monoecious seeds in the packet. You’ll be able to tell the monoecious seeds apart by a special colored dye on the seed coat, or they’ll be in a small, separate packet. If your gynoecious seeds don’t come with monoecious ones, you’ll have to purchase your own monoecious seeds or seedlings.
Because they’re such heavy producers all at one time, you might find yourself with more cucumbers than you can eat from your home garden. So unless you plan to make lots of pickles, sell your extras or give them away, you may want to stick with a monoecious variety.
Parthenocarpic are the newest hybrids on the cucumber scene. They’re the seedless varieties you may see in the grocery store.
Parthenocarpic are a subset of gynoecious varieties in that they only produce female flowers. Because they don’t produce seed, they don’t need any pollination at all. These are a good choice if you’re growing in a greenhouse or otherwise indoors since any insect activity could lead to cross-pollination and odd seed production.
5 Ways to Get More Female Cucumber Flowers
Plants are incredible- they can sense if the conditions are hospitable for producing seeds for the next generation. So if you don’t provide the right environment, your cucumber plants will not direct energy into producing lots of female fruit-producing flowers. In this case, you might end up with few flowers altogether, or just a lot of male ones.
Since one male flower produces enough pollen to pollinate multiple females, increasing the number of female flowers is key to getting a good cucumber crop. Let’s look at the ways to do just that:
1. Make Sure Your Cucumbers Get Plenty of Sun
It takes a lot of sun-powered photosynthesis to produce enough energy to ripen juicy cucumbers. So make sure your cucumber patch is in a location that gets at least 6 hours of full sun each day.
That might mean trimming back some overgrown shrubs or trees that are shading out the garden. Also, make sure not to plant your cucumbers right next to tall garden plants.
2. Don’t Overcrowd the Cucumber Patch
Allow at least 2 feet between plants if you’re going for a patch-style garden layout. If you have your cukes on a trellis, you can reduce that spacing to 1 foot between plants.
While it might seem that packing as many plants into your space will result in the most fruits, the opposite is actually true. When plants are overcrowded, they compete for nutrients, sun, water…. In that case, typically none of the plants produce very good crops.
Also, an overcrowded garden is a breeding ground for plant diseases and pest infestations- either of which can quickly decimate your cucumbers.
3. Give Cucumbers Consistent Water
Cucumbers need roughly 1 inch of water every week to nourish the plants and produce juicy, water-filled fruits. That can be in the form of rainfall or manual watering.
I can’t even tell you how many times I’ve been so surprised by how slacking off on watering for a few days really impacts my garden’s growth. So this one’s important!
This video from MIGardener shows a great way to determine what’s 1 inch of water.
4. Fertilize Cucumber Plants Regularly
Plan to fertilize your cucumbers every 2-3 weeks during the growing season. Producing all those fruits is hard work for your plant, and besides that, cucumbers that come from nutrient-rich soil will have the best flavor.
Compost is always my favorite fertilizer, but I also like some commercial organic blends, like Dr. Earth Home Grown.
5. Treat Cucumber Pests Immediately
Some pests damage your plants directly by eating plant tissue, and some can also be disease-spreaders. So they’re bad news and need quick action- besides slowing flower production, some pests can also cause leaf yellowing.
Side note: We’ve dedicated an entire article going over a few reasons why your cucumber leaves might be turning yellow. Check it out to learn more.
Cucumbers are susceptible to quite a few pests:
- Squash vine borers
- Cucumber beetles
- Squash bugs
I’ve had a few of these unwelcome visitors in my garden before- and I can tell you it’s infinitely easier to deal with them if you catch the problem early. One of the best ways to combat pests is to spend time looking over your plants regularly- daily, if possible. Look on leaf undersides and stem crevices. If you spot any pests, start treatment right away.
For cucumber beetles and squash bugs, pick off as many as possible by hand and drop them into a container of soapy water. If you see any eggs, stick a piece of wide tape over them and pull the tape off, bringing the eggs along with it.
After manually removing as many adult bugs as possible, spray your plants with insecticidal soap. This is also effective against aphids.
Bacillus thuringiensis (BT for short) is a beneficial bacteria that kills certain pests, including squash vine borers, but doesn’t harm friendly garden insects.
Inject BT directly into the stem as a preventative measure against pests. Some gardeners also try it as a treatment for an existing vine borer problem. However, I recommend the manual removal method for getting rid of squash vine borers- I’ve had better luck with that in the past.
Here’s how I do it. Use a clean razor blade to slice along the grain on the vine, starting right above when you see the hole from the borer. Being careful not to cut through the entire stem, gently pry it open and manually remove the borer larvae.
How to Treat and Prevent Cucumber Flower Drop
Once you’ve got those prized female cucumber flowers, there’s nothing more discouraging than finding them shriveling up and dropping. So your job’s not done yet- you’ve got to keep those flowers healthy and happy on the vine.
Keep the Roots Moist
Cucumber plants have shallow root systems that make them prone to moisture loss through evaporation. And once the roots dry out, the plant will drop flowers to conserve energy.
There are a couple of things you can do here:
- Stay consistent in your watering. Especially in the heat of summer, don’t skip watering unless rain is in the forecast for that day. Try to get out and do your watering before mid-morning- that keeps water from evaporating too quickly or scorching wet leaves with the sun’s strong rays.
- Apply a thick layer (2-3 inches) of mulch. Mulch acts as an insulator, keeping moisture in the ground where it belongs and absorbing the sun’s rays to keep the soil cooler. Grass clippings, straw or compost are the best materials here, but if you can’t get those, well-aged hardwood chips can work too.
Keep Phosphorous and Potassium Levels High
While adequate phosphorus and potassium are important at all stages of a plant’s life, flowering cucumbers demand even more of these key nutrients to produce healthy blossoms and fruit.
At this time, hold off on high-nitrogen fertilizers that primarily support leaf production. Instead, apply bone meal for phosphorous, and composted banana peels are outstanding for potassium.
Pollinate Flowers by Hand
Female flowers have a short window of time to get pollinated- about a day or so. If pollinating insects don’t get the job done in that time, the flowers will dry up and fall off.
But you can help nature along by pollinating the flowers yourself. It’s pretty easy- I use a cotton swab, but a small clean paintbrush also works well. Use the swab or brush to pick up pollen from a male flower- you’ll see the bright yellow pollen easily.
Then gently rub the pollen onto the stigma of a female flower. You should be able to pollinate a few females with the pollen from one male, but if you have many flowers to pollinate, you’ll have to repeat the process of gathering fresh pollen from different males a few times.
Some gardeners tie or tape the female flower shut after pollinating, but I’ve never done that. I always think that maybe some pollinators will still visit later in the day, so why shut the flower down early?
Frequently Asked Questions about Cucumber Flowers
Cucumbers are a great plant to have in your garden- you just can’t beat that fresh, juicy crunch! And when you understand the importance of cucumber flowers and how to keep them healthy, you only increase your chances for a better harvest.
I hope you’ve found my tips and experience with cucumbers and their flowers helpful. If you have any other thoughts or questions, I’d love to hear about them in the comments. There’s truly no better way to learn than from each other, so please feel free to share!