The Best Cucumber Fertilizer – Soil vs Hydroponics

The Best Cucumber Fertilizer – Soil vs Hydroponics

If you are looking to grow the perfect veggie for a salad all year long, cucumbers make an obvious choice. The good news is that you can grow cucumbers both with soil-based methods and hydroponics systems.

However, you need the right fertilizer mix to grow cucumber seeds into healthy and fresh veggies. We’ll assist you in that effort by going through the best cucumber fertilizers for both growing techniques. 

With this guide, growing hydroponic cucumbers will seem like a breeze. If you go the soil planting route then you’ll also learn everything you need to know about growing delicious cucumbers.

Traditional Method vs Hydroponic Cucumbers – What’s The Difference?

Although you can grow cucumber plants with both methods, it makes a great difference whether you choose a soil-based planting method or hydroponics. Growing cucumbers is easy once you get to know the differences in fertilizers when comparing the two methods.

WIth plant-based growth, you will have to switch the nutrients as the plant evolves into a seedling, and after you transplant it into the soil. On the other hand, growing hydroponic cucumbers requires a bit of a different approach.

You will be planting the seedlings into the growing medium with most methods, and using sprinkles and water channels to spray the roots with nutrients.

The growing environment also affects the development of your freshly planted veggies, so let’s take a look into the two main planting types and fertilizers used.

Growing Cucumber Seeds In Soil

Cucumber Seeds On Top Of Soil
Cucumber Seeds On Top Of Soil

The process of growing cucumbers in the soil is completely different from that of hydroponics. It also requires a different approach to the fertilizers and how they’ll need to change in the different life cycles of the plant.

If you’re a first-time cucumber grower, we’ll go through the process thoroughly and discuss the soil fertilizers along the way.

Fertilizing Seeds And Seedlings

At the start of the growing season, place the seeds into net pots or other small containers. Before the cucumber vines appear and before you even transplant the plant and its roots into garden soil, you’ll need to start the first fertilizing cycle.

Fertilizer On Hand For Seedling
Fertilizer On Hand For Seedling

One way you can provide a proper start for your cucumber plants is to add Urea into the soil

It’s enough to add a single tablespoon filled with Urea fertilizer that contains large amounts of Nitrogen into a gallon of water. Once you plant the seeds and fertilize the soil this way in a small net pot space, it will entice the leaf growth and give your cucumbers a fresh green color.

You can also use a high Nitrogen-concentrated NPK fertilizer at the beginning of the process instead of Urea. The soil will absorb the nutrients and high Nitrogen concentration will help grow healthy seedlings.

After two weeks at most, you will be ready to transplant the cucumbers into garden soil as they’ll need larger space to grow and spread their roots.

Transplanting The Seedlings

After transplanting the seeds, your fertilizer solution will need to be changed. The proper nutrient solution for a young cucumber plant will now require lower Nitrogen concentration and higher doses of Phosphorus and Potassium.

Although Nitrogen is needed for getting a lush green seedling, to get large cucumber fruit production and a healthy plant, you’ll need to change the formula.

After the seedling phase is finished, you can easily boost the Phosphorus and Potassium to more than double of the Nitrogen concentration. 

An NPK solution like 5-10-10 can be used, or you can even us higher Potassium concentrations in your nutrient solution. For example, if you want to achieve steady growth and sturdy roots, an NPK ratio of 8-16-36 could be a perfect option.

It’s also a great solution for growing a hydroponic cucumber plant, as we’ll discuss a bit later on. After the initial growth period, you can start adding water and NPK solution once a week to make your cucumbers thrive.

You’ll also need to prune them to deal with the vines and maintain a steady fruit yield. On hot summertime days, make sure to add a layer of mulch to keep the soil temperature optimal and to help keep the pests away.

Prepare A Compost Solution

Another important technique to have in mind when growing cucumbers in the soil is to use compost as a fertilizer. You can even use last year’s compost as aged compost is a perfect blend for cucumbers.

This is due to the low Nitrogen concentration and it can be used right after feeding the seedling as we discussed. Moreover, compost releases the nutrients into the soil slowly, so they stay in the soil for quite a while.

This result is a long-term nutrient supply for your cucumbers, while your veggies will also be resistant to many soil-bourne diseases this way. The only slight downside is that you’ll have to prepare the compost about a month prior to transplanting the seedlings.

A proper mix for cucumbers would be to use 50% soil and 50% compost to encourage healthy growth. The soil will also be loosened a bit and it will feature better drainage.

Compost planting has other benefits, including high concentrations of Phosphorus and Potassium, which is exactly why it makes a perfect choice for cucumbers.

How To Fertilize And Grow Hydroponic Cucumbers?

Growing hydroponic cucumbers takes a whole different approach than soil-based planting. It can also reduce the pest and disease stress to a minimum, given the water-based growing system without the need for soil.

With the hydroponic system, you will mostly need a fertilizer mix including a synthetic NPK addition

Hydroponic production also depends on the cucumber type and growing method among different hydroponic systems. 

Best Hydroponic Setup For Cucumber Plants

Hydroponics Growth Of Plant Setup
Hydroponics Growth Of Plant Setup

Growing cucumbers hydroponically requires having a proper approach and it all starts with the best systems you can choose. Since cucumbers need space for their roots to spread, you can rely on techniques that use a growing medium for seedling development.

These are the overall best hydroponic systems you can use to grow hydroponic cucumbers:

  • Ebb and Flow system
  • Drip system
  • The Dutch Bucket system

With these systems, the cucumber plants are firmly attached to a net pot or a growing bucket via growing mediums like coco coir or pebbles. 

In the drip system, the nutrient solution mix is provided to the roots through the small channels and sprinklers..

While the ebb and flow systems use a different approach with water channels that rely on flood and drain cycles. Cucumbers are placed in buckets with a drain hole so their roots come in contact with the nutrient solution during the flood cycle. 

Another hydroponic system that is perfect for hydroponic cucumbers is the Dutch Bucket system. It relies on an irrigation line through which the nutrient solution flows with the help of a water pump.

Your cucumber plants would be placed in large buckets with the growing medium in this type of hydroponic system. The irrigation channel provides fertilizers for every bucket in this space-saving system and you can make adjustments for your hydroponic cucumber plants.

Cucumber Types You Can Grow With Hydroponics

Growing cucumbers hydroponically requires knowing the best cucumber variety you can develop without soil. Some of the best species for hydroponic growing include:

  • Sweet Beit Alpha cucumbers
  • Lebanese cucumbers
  • Bush Champion cucumbers
  • Spacemaster cucumbers

These cucumber varieties are best for hydroponic systems and they thrive with a hydroponic fertilizer mix.

Cucumbers make some of the highest-yielding plants out of the soil free growing methods. All you have to do to increase your chances of success is to choose one of the hydroponic systems we mentioned and use a cucumber seed of one of the above varieties for a rapid growth rate.

Best Hydroponic Cucumber Fertilizers

Placing cucumbers seeds into the growing medium at least a couple inches deep should be enough for them to germinate as fast as within 10 days. This should be done in a small container before placing the seedling into a hydroponic system.

The next step is to transfer the germinated seedlings into a hydroponic system with a pH of 5.5 or 6.0. Place the seedlings in buckets with drain holes for the roots to spread and intake the nutrients from the system.

Note that your cucumbers need space to spread roots even though you are not using a soil-based technique.

One of the best hydroponic fertilizers would be the 8-18-36 NPK ratio. As we already discussed, this ratio is a perfect choice to use after the seedling phase of development. With the lower need for Nitrogen and a higher need for Phosphorus and Potassium, you can also use a 5-10-10 fertilizer.

Vegetables Grown In Hydroponics
Vegetables Grown In Hydroponics

Regardless of the method you are using, the nutrient tank with the fertilizer solution should be changed out approximately once every few weeks. 

That’s due to the forming of bacteria and fungi that could thrive if the water isn’t changed, and you should change the nutrient solution even more frequently if you can’t maintain a proper pH for cucumber growth. 

The desirable pH for growing hydroponic cucumbers ranges from 5.5 to 6.0.

On the other hand, changing the primary nutrient solution occasionally will result in steady growth, but for optimal results you should add a secondary solution and micronutrients, which we’ll cover in the next section..

Secondary Nutrients For Hydroponic Cucumbers

Growing cucumbers hydroponically also requires secondary nutrients and micronutrients being added to the fertilizer mix. Cucumbers specifically have a high need for Magnesium and Calcium as the secondary nutrients. They serve the important purpose of neutralizing organic acids. 

Your plant will need Magnesium added to the mix during the entire growing season. 

The perfect time to add the Calcium into the fertilizer solution is once your hydroponic cucumbers start fruiting. Calcium, like Epsom salts, also helps the roots absorb other nutrients.

Until that point, it’s enough to just fertilize with the NPK and Magnesium by changing the nutrient solution once a week. However, with the first appearance of fruits, add Calcium into the mix and keep it as one of the secondary nutrients until the end of harvest.

Placing a trace of Boron and Zinc into the mix as micronutrients will also enrich the fertilizer solution for hydroponic cucumbers. These two minerals serve a great role in raising the absorption rate of other nutrients in the mix.

One example of how you can pair the nutrients is to use the 8-16-36 NPK rate with Magnesium-Sulfate as a secondary nutrient. 

Also known as Epsom salt, this compound helps in the complete growth phase of the plant from germinating the seeds to producing more cucumber fruit and greener leaves.

After two months, when the fruits appear, you can start adding Calcium into the mix as well.

Final Thoughts

Regardless of your cucumber growing method, some fertilizer solutions may need to be added to either the soil or hydroponic nutrient water tank. 

If your aim is to grow hydroponic cucumbers, this guide will shed some light on the best hydroponic systems and fertilizers to add.

On the other hand, you now know how feeding the seeds with Nitrogen-rich Urea can benefit your cucumbers before placing the seedlings in garden soil.

Frequently Asked Questions (FAQ):

Which method is better for cucumber growing: soil or hydroponics?

It all depends on your preference, as you can grow hydroponic cucumbers with just as much success as soil-based ones. Still, there are more cucumber varieties that you can grow with soil, and you will have to carefully choose the best species for a hydroponic system.

Do cucumbers thrive well hydroponically?

Hydroponic cucumber varieties like Bush Champion, Lebanese and Lemon cucumber thrive hydroponically as much as they do with soil-based methods. You can expect the first harvest around 70 days from planting in a hydroponic system.

Which fertilizer ratio is best for growing healthy cucumbers?

Whether you plan on growing soil-based or hydroponic cucumbers, you need a fertilizer ratio with higher a Phosphorus and Potassium concentration like 8-16-36. However, with soil-based methods, you need to add a rich Nitrogen fertilizer before transplanting the seedlings.

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