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Cucumber plants produce some beautiful yellow flowers, but what are you supposed to do when that happens and why do the flowers even appear? I asked myself those questions the first time I grew cucumbers and now that I know the answers, I’ve written this article, so you can also know.
There is usually no need to do anything when cucumber plants are flowering. That’s because most modern cucumber varieties don’t produce male flowers. Some varieties do produce male flowers, however, which should be removed as early as possible to ensure the best harvest.
I will explain exactly how you can tell if your cucumber plants have male flowers that you need to remove as well as how to do it in this article. I also explain why cucumber plants flower, what time of the year it is supposed to happen, and much more, so keep reading to learn everything you should know about flowering cucumber plants.
Before I wrote this article, I called one of the most experienced gardeners I know who has given me a lot of good advice in the past to ask for some input. He taught me something about cucumbers and flowering that I didn’t know, so I will also be sharing that below.
What to Do When Cucumbers Are Flowering (I Asked an Expert)
There is no single answer to what you should do when your cucumbers are flowering because it’s not always the same. I’ve written this to help you find out what you should do in your specific situation.
The first time I grew cucumbers, I didn’t do anything when the plants started flowering and I got a lot of fruit from them, but after the season was over, I thought about if I could have done something differently. For example, I read that it is important to remove male flowers from your plants, but I wasn’t sure why.
So I reached out to one of the most experienced gardeners I know who has given me good gardening advice many times in the past and asked him about the male flowers and if there was something you should do when cucumber plants are flowering. Here is what he told me.
You rarely have to do anything when cucumber plants are flowering since most modern varieties don’t produce male flowers. Some varieties, however, do produce male flowers that you should remove as early as possible since female flowers pollinated by male flowers can produce yellow, bitter-tasting fruit. This happens because the flower becomes pollinated and focuses on producing seeds.
If you don’t know how to tell male and female cucumber flowers apart, I recommend that you read this article, where I explain it and show photos of both types.
You can pinch off male cucumber flowers with two fingers, but I recommend using pruning shears to get a clean cut since it reduces the risk of damaging the plant as well as the risk of pests and diseases. I bought these pruning shears recently and I am thrilled with them.
If you are not sure if the flowers on your cucumber plants are male or female, I explain how to tell now.
How to tell if a cucumber flower is male or female?
The easiest way to tell male and female cucumber flowers apart is to look behind the flowers. Female cucumber flowers have a small cucumber fruit at the base which will become larger with time. Male cucumber flowers do not have small cucumbers at their base but are instead attached directly to the stalk.
Here is a picture of a female flower from a cucumber plant I had in my greenhouse. Notice the tiny cucumber fruit that the flower is attached to. This is the actual fruit that you will harvest and eat once it gets larger. Male flowers do not have this. Instead, they are attached directly to the stalk.
Why Are Your Cucumber Plants Flowering? Simple Explanation
You should not worry if your cucumber plants are flowering. In fact, flowering is a very good thing since it means your plants are starting to produce fruit, but why does it even happen?
Cucumber plants flower as a natural part of their lifecycle and reproductive cycle. The goal of a cucumber plant’s reproductive cycle is to produce seeds. Flowering means that the plant is starting to produce fruit and seeds.
Depending on the cucumber variety you grow, you might have noticed that there are no male flowers on the plant, but instead only female flowers. There is a good explanation for that.
Why are your cucumber plants only producing female flowers?
At some point, I noticed that my cucumber plants weren’t producing any male flowers, which made me curious, so I called a very knowledgeable gardener I know to ask about this. This is what he told me.
Most modern cucumber varieties do not produce male flowers. This means that you don’t have to worry about pollination. That said, it is still a good idea to keep an eye out for male flowers, because several varieties still produce them.
Below, I will explain when cucumber plants usually flower and what factors affect it. I also share some tricks you can use to keep your cucumbers flowering and producing fruit for longer than they normally would.
What Time of the Year Do Cucumber Plants Flower?
Cucumber plants usually flower within about 1-2 months of being planted depending on their growing conditions.
Cucumber plants usually start flowering in June or July and can continue into October if they have good growing conditions. That said, many factors determine when cucumber plants flower and they can sometimes flower much earlier than June and much later than October.
Perhaps the most important factors for cucumbers when it comes to growing conditions are temperature and sunlight. Other than affecting how fast the plants grow, these also determine when the plants begin flowering.
Something I do to keep my cucumber plants flowering and producing for longer than otherwise is to grow them in a greenhouse. A greenhouse retains some heat and doesn’t get as cold at night as outside, which means that the plants usually have a few more weeks, or even more, to flower and produce fruit.
I managed to keep two cucumber plants alive and producing fruit well into October this year, but it seems like that was the limit (for me). Here is a photo from late September and as you can see, there are still a couple of flowers and cucumbers on the plants, but they are starting to die back.
Greenhouses are great for growing cucumbers. Extended growing seasons is a big reason but far from the only one. That said, you should not be discouraged if you don’t have a greenhouse. Cucumbers can also grow perfectly well outside and there are also several advantages to doing that over using a greenhouse.
I have written another article where I compare all the advantages of growing cucumbers in a greenhouse and outside, so you can see which method you prefer. The article is here.
How to Make Cucumber Plants Produce More Flowers and Fruit
The more flowers your cucumber plants produce, the more fruit you will potentially get to pick and eat. Lucky for you (and me), there are some things we can do to help our cucumber plants produce more flowers and thereby more fruit.
The best way to increase the number of flowers on cucumber plants is to give them the best possible growing conditions. Temperatures between 75-85° F (about 24-29° C) and large amounts of direct sunlight combined with nutrient-rich, well-draining soil results in the most cucumber flowers and fruit.
It can be difficult to control how much sunlight your cucumber plants get and how warm it is (unless you grow them indoors with grow lights), but you have full control over the soil your plants grow in.
The soil is extremely important for cucumber plants. First of all, it is how your plants get their nutrients, which determines how fast and how well they grow. Secondly, the soil content determines if water stays around the roots for a long time or if it runs through easily.
If the soil doesn’t drain well (for example, if it contains a lot of clay and very little sand), chances are that your plants will become overwatered, which can lead to root rot, which kills the plants.
I have written another article (which you can find here) about how to make the perfect soil mix for your cucumbers, how to tell if your soil is good enough, and how to improve it if it isn’t.
If you grow your cucumbers in pots or containers with one or more drainage holes, a cool trick you can use to encourage root growth, which ultimately leads to more productive plants, is to water them from the bottom. I explain how to do it and why it is such a good trick in the article on this link.
Are You Cucumbers Flowering but Not Fruiting? 5 Reasons
A very common problem for people who grow cucumbers is that their plants can sometimes be flowering but not produce any fruit. I have also experienced that. I have found these five potential reasons that you should be aware of.
- It is too early for female flowers to have formed
- The plants aren’t getting enough water
- The plants aren’t getting enough sunlight
- The temperature is too low
- The plants aren’t getting enough nutrients from the soil
The most common reason why cucumber plants are flowering but not producing fruit is simply that it takes a bit of time before the fruit starts growing. According to this article from New Mexico State University, the male flowers appear first, and how much time it takes from when the male flowers appear until the female flowers appear depends on the variety and growing conditions. You won’t see any fruit until female flowers appear on your plants.
Another common reason is that the plants just don’t have good enough conditions to produce fruit. An example is lack of water. According to Healthline.com, cucumbers contain 95% water, which means that they need plenty of water to even form on your plants.
Cucumber plants can also flower but not produce fruit if they don’t get enough sunlight, if the temperature is too low, or if the plants don’t get the nutrients they need from the soil. I’m almost certain that’s what happened with the small cucumber plants in the photo below, which I grew some time ago.
In some cases, these things can also cause the plants to stop growing entirely, and then you have to react now to save them. You can read more about why cucumbers might stop growing as well as what to do about it on this link.
It might be a bit hard to see the photo, but there are a lot of small flowers and even tiny fruits (at the base of the female flowers), but almost none of the fruit ever grew larger. Despite having a lot of flowers, I only got to pick two tiny cucumbers from those plants.
Does a Cucumber Plant Die After It Is Done Flowering?
For some plants, flowering is the beginning of the end and that is technically also the case with cucumber plants, but they will usually stay alive and flowering and producing fruit for several months before they die.
I have written an article where I share some tips that can help you keep your cucumber plants alive for longer. You can find it here.
Cucumbers are annual plants, which means that they don’t come back every year. Soon after they begin flowering, they will start producing fruit and trying to produce seeds, which is the whole “goal” of the plant’s reproductive cycle, of which flowering is an important part.
Cucumber plants can live for several months after they start flowering. The cucumbers I had in my greenhouse this year were flowering from early July until early October. They usually stop flowering and die because it gets too cold for them.
Cucumber plants produce seeds when female flowers become pollinated by male flowers and when that happens, the plant will no longer produce good-tasting fruit.
Female cucumber flowers that become pollinated by male cucumber flowers will produce yellow bitter-tasting cucumbers and once that happens, you might as well pull up the plant and plant a new one, because you will not get more good fruit from it.