How to grow hydroponic cucumbers

How To Grow Delicious Hydroponic Cucumbers

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Cucumbers don’t last long around our house. We use them in many different kinds of meals, salads, and snacks; my favorite being bread and butter pickles. Hydroponic cucumbers are easy to grow, grow fast, and produce a lot. Here’s a simple guide to growing hydroponic cucumbers.

Any cucumber variety will work growing hydroponic cucumbers. You should choose the variety based on the purpose (cucumbers or pickles) and by your garden setup. I like using bush varieties like Spacemaster and Bush Champion cucumbers.

Getting Hydroponic Cucumbers Started

Germinating seeds- Starting from seed is my preferred method of getting my cucumber garden started. Cucumber seeds are easy to germinate, germinate fast, and seedlings grow quickly. Seeds should be kept between 70 and 85 degrees and take 3-10 days to germinate.

Cloning Cucumbers- Cucumbers can be cloned but I’ve found the process more work/time than just starting from seed. Cloning plants using hydroponics is an easy process that guarantees you to get a plant with the same traits as the one being cloned.

Transplant plant from dirt- Another way to get your hydroponic cucumber garden going is to transplant them from dirt. Though buying plants is the more costly option, it does save you the time of having to mess with germinating seeds. To find out more you can check out this article on how to transplant a plant from dirt to a hydroponics system.

What Hydroponic Systems Works Best For Hydroponic Cucumbers?

There are a few things to consider before choosing the best hydroponic system to grow your cucumbers. You will need to decide where your growing and what variety of cucumbers you want to grow.

Growing indoors often means less room, so I would recommend a bush variety of cucumber. For my indoor cucumbers, I opted for deep water culture, in 5-gallon buckets and tubs. If you have an ebb and flow system with a big enough grow bed and light coverage, those systems also work well too.hydroponic cucumber ready to be picked

Growing cucumbers outdoors is easier than growing indoors and typically produces more due to having more space. Outside cucumber gardens can be trained to grow vertical more easily, meaning less space is required between plants.

When growing cucumbers outdoors,  I would recommend using bubble buckets, drip systems, dutch bucket systems, and large ebb and flow systems. Even when growing bush varieties I recommend using a trellis.

Cucumbers will grow a large root system and be heavy, especially when fruiting. This makes them ill-suited for nft and rail systems. Make sure your system and plant support can hold the weight of your full-grown cucumber plant.

What Is The Best Temperature For Hydroponic Cucumbers?

Hydroponic cucumber plants can tolerate a wide range of temperatures. Cucumbers grow well in a range of 70-80 degrees during the day or lights on period. Plants benefit from a drop in temperature of about 10 degrees to simulate outdoor patterns.

Spacing Requirements For Hydroponic Cucumbers

Hydroponic cucumbers need plenty of room to grow. With that said you can still place a few cucumbers in hydroponic systems in “patches”, just like in a traditional garden.

Cucumber patches need to be 2-6 feet apart depending on the variety and how you train the growth. Plants that are left to vine out on the ground need the most space. Bush and container varieties should be about 3-4 feet apart while plants grown straight up only need a couple of feet between plants.

You can always prune and pinch your cucumber plant back to control its growth.

How Much Light Do Hydroponic Cucumbers need?

Cucumbers grow like crazy and can produce a lot of fruit. That production takes energy, so make sure to give your hydroponic cucumbers plenty of light. Hydroponic cucumbers should receive full sun or 12-14 hours of light each day.

The recommended pH level for hydroponic cucumber plants is 5.0–6.0.

Hydroponic Cucumbers Nutrient Requirements

Cucumber plants should start off being grown with a nutrient regimen geared towards vegetative growth. A simple one-part nutrient solution like Dyna Gro Grow works well up until your cucumber plants are ready for flowering.

female hydroponic cucumber flower

For the flowering stage, you should switch to a nutrient regimen with less nitrogen and more phosphorus and potassium for flower and fruit production. A 1 part nutrient like Dyna-Gro Liquid Bloom is easy to use for the flower and fruiting stage of growth. I also use Dyna-Gro’s Pro Tekt throughout the growth cycle.

One part nutrient regimens are easy to use but don’t allow you the flexibility to tailor your nutrients to the specific crop.

I’m a big fan of Dyna-Gro’s products because they are simple to use and work well for general hobby growing. When you start to understand the nutrient needs of the plant your growing, you may look to a more advanced nutrient regimen like General Hydroponics Flora Series. Plants can also benefit from various supplements that go by different names depending on the nutrient regimen you’re using.

Pollinating Cucumbers Grown Indoors

Cucumbers grown indoors will need some help with pollination, though I typically try to hand pollinate my outdoor cucumbers as well. Cucumber plants are monoecious plants, meaning they produce flowers with male and female parts on separate flowers. Cucumber flowers are easily distinguishable. Female flowers (shown in the picture above) will have a small cucumber at the base of the flower, while male flowers (shown below) are just a cluster of flowers, with no cucumber at their base.

male cucumber flowers

There are a couple of different ways you can pollinate your hydroponic cucumbers. You can use a q tip or small paint brush and gently rub the male flower then transfer the pollen to the flower to assist pollination. Another option is plucking the male flower and rubbing it on the female flower. For more in-depth information on hand pollination, check out this article detailing 3 methods of hand pollination.

Harvesting Hydroponic Cucumbers

Cucumbers should be ready for harvest in about 50 to 70 days after sprouting, depending on the variety. Since the cucumbers on the plant start growing at different times, they will also be ready to harvest at different times. Cucumber should be medium to dark green, firm, and need to be picked before any yellowing.

Hydroponic cucumber in ebb and flow system

To harvest, snip them about a quarter-inch above the vine. Some cucumbers may be prickly so you may want to use gloves. They will come off by hand when handling or when washing. You can always take a veggie brush and give them a good scrub as well. Cucumbers left on the vine until the recommended harvest date are typically less prickly.


I hope you have found this article helpful! If so, please take a second to show us some social media sharing love. I’ve also put together a pretty nifty infographic you can check out below.

6 Answers

  1. Wally Collett
    November 8, 2019 at 3:17 pm

    I faithfully follow all of the information that you put out on Hydroponics. I was so glad to read about hydroponic cucumbers. They appear so successful. But I am so disappointed with mine again. This is my third year of trying to grow cucumbers with little success. I follow every bit of information I can get but still I have problems with my cucumbers. The most I have ever been able to harvest was three cucumbers last year. A few weeks ago I planted in my ebb and flow system three cucumber plants that I grew from seed. And just moments ago I noticed that awful brown coming on the leaves of one of the three plants. After three years of trying and having this happen every time is very disappointing to say the least. No matter how I try to cure or prevent it, it never fails to appear and will gradually consume the whole plant. I am ready to throw the whole thing out the back door.

    1. NoSoilSolutions
      November 9, 2019 at 3:19 pm

      I’m sorry to hear about your trouble Wally, but don’t give up! Have you tried growing some other plants besides cucumbers? They are not the easiest plants to start with.

      I know you mentioned in your comment awhile back that you were using a three-part nutrient solution, maybe trying a one-part nutrient solution like Dyna Gro Grow would be easier to start with?

      Feel free to send me questions and pictures of your system at and I will be happy to help you! I’m also starting a Hobby Hydroponic Faceboook Group that you also might find helpful!

      1. Wally Collett
        November 10, 2019 at 9:50 pm

        Thank you Michael for replying. This afternoon I again sent you another comment but it does not seem to have gotten posted for some reason. So I will try it again. Cucumbers were not the first nor the only plants I have grown hydroponically. And I will continue with cukes until I get it right. I grow various kinds of lettuce, tomatoes, Swiss Chard, Green Peppers and Spinach. I have even grown celery and cabbage. My wife actually made cabbage rolls from the cabbage. At the moment I have some plants that are approaching harvest time. At one point I experimented with a two part nutrient called Green Planet Duel Fuel One and Two and results with that were good. But usually I use the General Hydroponics Flora Micro, Flora Gro, Flora Bloom, Floralicious, Flora Blend, Kool Bloom, Magi Cal and Rapid Start. I start with the mix for seedlings and progress to the mix for bloom and fruiting. My grow medium is Coco fibre and Ebb and Flo is my system. Mars/Hydro is my lighting source. My grow room is well ventilated with intake and out flow air as well as fans, and free of any pests. I faithfully follow every item of hydroponic information that you publish on your site. If you should have any further advice, suggestions or hints I would be more than pleased to receive them. Again thank you and I hope this one gets posted.

        1. NoSoilSolutions
          November 13, 2019 at 11:29 pm

          It sounds like you have a really nice setup! Just keep in mind, cucumbers are not the easiest plant to grow in hydroponics. Have you tried growing a different variety of cucumber? You may be dealing with some sort of disease and I know some varieties are more resistant to some diseases than others.

  2. Michael McLaughlin
    March 17, 2020 at 6:59 am

    Hello, have grown other hydro cukes in direct sun and have done well. Using grow light now but cukes growing slow in basement. 65-67 degrees. Is that too cold ? PH is good. They don’t look like their drinking any water though. There’s three big leaves and flowers but not getting any taller. Thank you

    1. NoSoilSolutions
      March 17, 2020 at 1:05 pm

      Plants usually grow slower in colder temperatures. 65-67 isn’t too cold but I would try to get them around 75 degrees and see if that gets them growing faster. When plants don’t look like they are growing, the first thing I always check is the roots to make sure they look good. If you’re good there I would say it’s the temperature. You may also try pinching off the flowers to start to allow the plant to focus on vegetative growth.

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