How to Grow Cucumbers Indoors (Quick Start Guide)


Cucumbers from seed sprouting up

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As one of the most hydrating fruits, being 95 percent water, cucumbers are also full of healthy antioxidants, minerals, and vitamins. Learning how to grow cucumbers indoors would allow you to have access to a fruit that is believed to encourage weight loss and control your blood sugar. These are just a few of the many reasons growing cucumbers indoors is appealing to so many people. But do you know how to grow cucumbers indoors?

Here are the steps for growing a cucumber indoors:

  • Plant your cucumbers in a deep hanging basket, a pot, or another sizable container made of ceramic or plastic
  • Mix compost with potting soil for the cucumber seeds
  • Water your seeds thoroughly and provide at least 8 hours of light daily
  • Harvest the cucumbers when the plant has reached a height of 10 inches

In this in-depth article, I’ll tell you everything you need to know about growing cucumbers indoors so you can get it right the first time. I’ll provide much more detail about which container to use, how far apart to space the seeds, and the signs that your plant is ready for harvesting!

What Pot or Container Should I Use to Grow Cucumber?

When growing cucumbers indoors, I’d suggest growing bush cucumbers. These cucumbers grow between 6 and 8 inches long with vines that are no more than 2 inches.

Bush cucumbers are ideal for indoor gardeners with only a cubicle or small apartment windowsill to dedicate to their plants. That said, you will need a sizable container for your cucumber plant to accommodate for its growth, especially by the time your cucumber plant is finally ready for harvesting.

You can use a pot if that’s what you’d prefer but growing cucumbers in a hanging basket can work just as well. The vines of the bush cucumber can stretch a little, but since they don’t get too large, you don’t have to worry about its vines trailing like an indoor ivy plant would.

Cucumbers grow best in moist soil, so pot conditions that maintain soil wetness are best.

When it comes to the type of container to grow your indoor cucumbers, choose a ceramic or plastic pot, as both materials are great for water retention. 

How Big Of A Container Do I Need?

It should be at least a foot deep and 5 gallons in size, that size can comfortably accommodate up to 3 cucumber plants at once.

Should you want to double your yield with up to 6 plants, then the width of the pot should be around 20 inches. 

Other cucumber species that are commonly grown indoors include Unistars, Corinto, Tyria, and/or Socrates cucumbers.

Unlike the bush cucumbers, growing these will almost certainly require using a garden trellis or a makeshift trellis in addition to your cucumber pot or container. The vines of these cucumbers can be longer, and the trellis will keep those vines contained and facing upward.

The best type of soil for a healthy, full cucumber plant is loaded with plant nutrients and organic matter. Mixing compost with the soil in a 50-50 mix is a smart plan.

The soil itself should drain well and be fluffy and aerated. Test the pH of your cucumber plant’s soil regularly. You want a reading of 6.0 to 7.0. Anything lower or higher than that should be amended so your cucumber yield is perfectly edible. 

How Many Cucumber Seeds Per Container?

cucumber seedlings growing in my window

Each seed needs 2 inches of space from one another, but use your discretion, as some indoor gardeners go as much as 12 inches apart if they’re planting their cucumber seeds in rows.

As you can see, I choose to start them each in their own small container and move them later on after they’ve sprouted up.

Cucumber seeds are not particularly sizable, as you’ll see in this Science Direct report. Depending on the species, the average seed thickness is between 0.69 and 1.68 millimeters, the width is 2.49 to 4.21 millimeters, and the length is anywhere from 6.89 to 9.07 millimeters.

That said, you don’t want to crowd your cucumber seeds. If you don’t space them apart, none of the plants will grow to their full potential. 

How Deep Do You Plant Cucumber Seeds in A Pot or Container?

Bury each seed into the soil 12 millimeters or a half-inch deep. 

How to Care for a Growing Cucumber Plant

Okay, your pot is selected, your soil is in the pot, and your seeds are buried, here are the steps to follow to encourage growth from your cucumber seeds. 

Watering Your Indoor Cucumber Plant

Immediately after burying the seeds, you want to water the soil so it’s thoroughly wet but not soaking. If the soil has a soup-like texture, then you’ve watered too much.

After that initial watering, how often you water your growing cucumber plant will be depend on the moisture levels in its soil.

To test soil moisture, take a clean hand and put it an inch or two deep into the soil. If the soil doesn’t feel very wet to the touch, then your cucumber plant will need water within 2 to 3 days. When the soil gets mostly dry, it’s time to water your cucumber plant again.

All said, every week, expect to feed your cucumber plant about an inch of water. Do keep in mind that this isn’t all at once!

You can use a drip irrigation system if you’re having a hard time keeping up with the cucumber’s watering needs, but check that the soil isn’t getting over watered if this is the method you use. 

Whether you do it by hand or you let an irrigation system take care of it, your cucumber plant needs a consistent amount of water each and every time.

Improperly Watering Your Indoor Cucumber Plant Can Affect its taste

If you go too long without watering the plant, its flavor could come out bitterer than a cucumber should taste. Overwatering your indoor cucumber plant can also change the taste by giving it a stale water flavor.

Cucumber Plant Lighting Requirements

When deciding where to put your cucumber plant indoors, a southerly-facing window is good place to set it up if possible. A southerly-facing window will do a great job at giving your growing plant the sunlight it needs.

In the early days, the plant requires more than 10 hours of direct light. Indoor plants that thrive on this much direct sunlight usually need to have artificial light a grow-light on them to make up for the days that don’t offer the full 10 hours every day. 

Once your cucumber plant begins sprouting leaves and vines, you can reduce its light to around 8 or 9 hours daily. It’s okay if the plant is exposed to light for only around 6 or 7 hours, but you don’t want to make that a regular occurrence. The less light the cucumber plant receives, the less generous its harvest will be.  

Cucumber Plant Temperature and Humidity Requirements 

Although cucumbers are typically a warm-weather plant, the wonder of having an indoor garden is that you can grow this fruit any time of year. Maintain temperatures between 65 and 75 degrees Fahrenheit for the cucumber, which shouldn’t be much of a challenge considering this range is comfortable room temperature.  

Attesting to its tropical preferences, you’ll undoubtedly spend more time getting the cucumber plant’s humidity levels right than focusing on its temps. By day, the cucumber plant prefers relative humidity between 60 and 70 percent.

At night, if you’re trying to recreate it’s ideal humidity, you’ll have to increase the humidity to a range of 70 to 90 percent. This isn’t a necessity, rather something to keep in mind to avoid humidity levels significantly below or above their ideal 70 to 90% range.

I always recommend using a humidifier for the humidity needs of your houseplants. I also recommend keeping some sort of temperature gauge in the room with plant that are sensitive to their environment. You don’t want to spend your nights sitting around misting your cucumber seedlings, as you’d have to do it around the clock. 

Fertilizing an Indoor Cucumber Plant

A good fertilizer will feed your growing cucumber plant the nutrients it requires so it can continue getting larger. Cucumber plants need much more phosphorus and potassium than they do nitrogen.

Since nitrogen is typically the first number in a three-digit nutrient ratio, make sure that digit is lower than the second and third numbers. You can also buy a fertilizer with fewer nutrients overall, like with a 4-4-4 ratio, but you’ll likely have to fertilize your cucumber plant more often with a weaker mix. 

When adding fertilizer to your cucumber plant’s soil, you only need a tablespoon if your pot is under 12 inches or if you’re growing one plant at a time.

When you have more than one plant or if your container is larger, then increase the amount of fertilizer to at least 2 tablespoons.

If the instructions of your fertilizer say to dilute it with water, then please do that. The usual amount of dilution is a gallon of water for every half-tablespoon of fertilizer. 

The first time you should fertilize your cucumber plant is upon planting it. Then fertilize again when your plant begins sprouting leaves. 

When to Expect Growth from a Cucumber Plant

First sign of growth takes about 7 to 12 days with a cucumber plant. When the seedlings begin sprouting, they’ll be only about 2 inches tall, maybe 3 inches.

If you fertilize your cucumber plant a third time during its active growing period, you might be able to speed up its growth. Otherwise, a bush cucumber plant is considered fully grown after 55 to 70 days. At 60 to 80 days your cucumber plant should have reached a height of around 10 inches. 

How do you know when it’s time to harvest the cucumber from the vine?

Gherkins cucumber

Pull out some measuring tape! Should you prefer gherkins and sweet pickles, then the cucumber only needs to be 2 inches before you can remove it from the vine.

Dill cucumber

For dill pickles, wait until the cucumber is 3 to 4 inches. If you’d rather your cucumber taste more like a cucumber, then the fruit should grow 7 to 9 inches long. The color will also be an indicator, as the cucumber should have turned dark green.

The worst thing you can do is wait too long to harvest your fruit.

When the cucumbers grow to lengths of more than 10 inches and they get very dark in hue, they tend to taste bitter. It will be a wasted harvest!

To safely remove cucumbers from their vines, use disinfected gardening shears or even a knife. Slice the fruit from the vine so you leave an inch-long section of stem attached to your cucumber, as this keeps the end from prematurely rotting. If you want to store your cucumbers to eat them later, preserving them like this is a must! 

The Benefits of Growing Cucumbers Indoors 

I won’t say growing cucumbers is the easiest of all the indoor fruits and veggies out there, but it’s not overly difficult either. While raising and harvesting cucumbers is its own reward, here are some other perks you’ll get to enjoy when you add cucumbers to your indoor garden. 

You Have Fresh Produce Anytime You Want It

I don’t know about you, but I hate when I buy produce at the grocery store, put it in the fridge, and then come back to it two days later only to find that the produce has gotten moldy or gross. I had been looking forward to eating it, and now I’m five days until grocery day, so I just have to wait it out. 

That won’t be the case when growing cucumbers in your home or office. As I mentioned before, when planted indoors, you can grow cucumbers all year long. Anytime you have a hankering for cucumber, you’ll know you have a fresh supply at the ready. 

Cost Effective

Do you ever feel like you’re getting ripped off for produce at the grocery store? I know the feeling!

Although growing your own fruits and vegetables isn’t free (you need to buy the pot, the soil, the fertilizer, the seeds, etc.), the amount of money you’ll save by growing your own indoor fruits and veggies garden makes everything worth it.

No more paying extra for produce, especially organic produce. Your grocery bills will be much more reasonable. 

It’s Easier to Start Eating Healthier

Once you see that first cucumber growing on the vine, your mouth will water. You’ll dream of the day when you can finally slice that firm cucumber and serve it in a salad or even as a light, refreshing side dish on its own.

Being surrounded by fresh fruits and vegetables that you’re growing makes it a lot easier to resist the temptation of ordering pizza or Chinese takeout. You’ll want to eat what you’ve grown, and that means a healthier diet. 

It’s Fun!

Last but certainly not least, growing cucumbers (and other indoor fruits) is truly pleasurable. Not only do you get to witness the beauty of your developing plant, but then you get to eat it as well.

You’ll love waking up each day and tracking the progress of your cucumber plant until the time comes to harvest it. Then you can start all over with a new cucumber plant. 

Fred Zimmer

I'm a lover of plants, animals, photography, & people, not necessarily in that order. Currently, I'm focused on photographing indoor plants & chachkies. I write & rewrite articles about creating an environment where indoor plants can thrive. I'm good at listening to music but bad at shopping to muzak.

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