Kratky Method: Hydroponics So Easy Even You Can Do It

With lots of folks having extra time on their hands the past several months, many have taken up gardening to fill spare time. The problem is, even with extra spare time, gardening is not always a welcome task. Fortunately, the Kratky method is a fantastic option for those practicing a green thumb without getting their hands dirty.

The Kratky method is a non-circulating hydroponic growing setup where plants grow above water.

This method of growing is not ideal for every plant you might want to harvest for food, but you can grow plenty of healthy vegetables with ease.

What Exactly Is the Kratky Method?

The Kratky method is a growing method that takes minimal effort beyond the initial setup.

You will not need pumps for the water, and you do not have electrical needs to keep your hydroponic garden going.

With the Kratky method, the plant is in what is called a raft, which is a net pot. A suitable growing medium surrounds the seed or plant, and the raft is above water with only a bit of the roots submerged.

The water itself is nutrient-dense, but as the water evaporates and goes down, it makes room for air. This air is full of oxygen and is good for the roots of the plants.

Once the water is gone, the plant is ready for harvest.

Best of all, the setup is one-and-done. You only measure out the nutrients once and set up the rafts.

Usually, if you have a plant sitting in water, the roots rot, which will kill that plant.

A cutting submerged in water will grow roots, except the water needs changing to keep the cuttings’ roots healthy.

Changing water is necessary because the roots take oxygen out of the water, and the roots will drown.

However, the Kratky method is perfect because the air pocket oxygenates the plant without changing out the water. As the water decreases because of the plant, it creates more of an oxygen-rich air pocket for healthy roots.

Who Is Kratky?

Bernard Kratky coined the term Kratky method after figuring out you can grow plants without circulating the water.

His research through the University of Hawaii suggested plants could easily be grown commercially with little effort. Also, his research initially focused on lettuce.

In the end, Kratky’s method is a fantastic option for home-growers, commercial growers, and everyone in-between.

The Kratky Method Is the Answer to Easy Gardening

With so many available gardening options, deciding which is the best fit for you might be overwhelming.

Do I garden in the dirt the old-fashioned way? Raised beds? Hydroponics?

Fortunately, the Kratky method of gardening is not only easy, it produces food and herbs quickly.

What kind of plants grows with the Kratky method?

The Kratky method is best for green leafy vegetables and many herbs.

Essentially, all lettuce does well with this growing system. Also, you can count on the following to do well:

  • Kale
  • Spinach
  • Arugula
  • Chard
  • Endive
  • Collard greens

Furthermore, if you wish to add herbs to your hydroponic garden, consider these varieties:

  • Thyme
  • Sage
  • Basil
  • Mint
  • Cilantro
  • Dill

These plants all have a rapid growth cycle, which lends itself to the Kratky method for growing.

While these listed plants are the easiest to manage and grow, you have other options. However, these bigger plants need larger containers.

Many growers find success with growing tomato and pepper plants, for instance.

Recommended Read: How To Grow Hydroponic Tomatoes

Remember the growing cycle for peppers and tomatoes are a lot longer. If you are cycling through and staggering growth for a continual supply of food, you want to stay aware of growing times.

Benefits of the Kratky Method

There are several benefits to the Kratky method.

First, it is mainly inexpensive to set up the system.

Also, it requires minimal effort and no heavy lifting.

You will not waste water, and those who are looking for low-maintenance hydroponic growing will appreciate the simplicity.

The Kratky Method Setup

With minimal initial setup and a few tools, your Kratky method hydroponic garden is ready to grow.

The reservoir and lid

You need a reservoir or container with a lid. Some hydroponic gardeners use mason jars or plastic cups for at-home setups or vertical gardens.

Other gardeners use large plastic storage tubs and alter the lids to fit the net pots.

Also, buckets work fine, as well.

Pretty much anything that holds water where you can fashion a lid is a good option.

If you want to get fancy, you could build an indoor or outdoor raised bed and add a plastic liner to hold water. Plywood with cut-out holes for the pots serves as a lid.

In some cases, the container’s top is narrow enough for the net pot to sit in without falling in. In other cases, you need to fashion a lid for the container and net pots.

Once you decide on your ideal setup, it is time to gather the net pots and growing medium.

Pots and medium

Next, you need net pots and a growing medium. The net pots allow the roots to grow their way out of the bottom towards the oxygenated air and water.

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The lip of net pots is enough to set on the top of a reservoir or lid without falling in. That is why it is vital to decide if you want to go small and try some window sill mason cars as a reservoir or go big with a larger setup. Your net pot size depends on your long-term plans.

However, you do not use plant soil in the net pots. Instead, you have other options.

Rockwool is one suggested growing medium. This material comes from melted rock spun into a fibrous slab or cube, and Rockwool feels like insulation but works for cuttings and seeds.

Another option is coconut fiber. Coconut fiber is also called coir, and it is a popular organic option. When manufacturers break up coconuts, the husks would typically be thrown away. Instead, the coir is reused. What makes this medium so popular is that it holds a lot of oxygen and water.

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The final option on our list of growing mediums is expanded clay aggregate. This material is clay heated in a kiln, so air bubbles form, making the clay look like honeycombs. This material is fantastic to allow airflow and the retention of water.

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I am so hungry: Plant nutrients

Plants need nutrients regardless of the growing method. With the Kratky method, the nutrients go into the water in the very beginning.

When you first set up this growing method, it might feel complicated. However, it is only a challenge the first time, and there are plenty of videos to help you out, such as this one:

One necessary and popular nutrient is FloraMicro.

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Also, Epsom salts and cal-mag are important, as well.

Follow the instructions on the nutrient labels according to your hydroponic gardening plans and test your pH before adding plants or seeds.

Putting It All Together

Once you have your materials, drill a hole in the lid of your container wide enough to hold the net pot by its lip.

Fill your reservoir with water, and add your plant nutrients according to the bottle’s instructions. You will want to use a pH meter to make sure your water is between 5.5 and 6.5.

You might have to go back and forth a bit to get the pH correct.

Next, add your growing medium and plant or seeds into the net pot and add to the cover of the container.

If you start with seeds, the water should touch the bottom of the net pot with the growing medium.

If you have a plant with toots already, let some roots rest in the water and some tucked in the growing medium.

Finally, watch your garden grow.

Factoring in Potential Issues for the Kratky Method and Solutions

As easy as the Kratky method is, you still must note some potential issues.

Bugs

One issue with the Kratky method is that standing water attracts mosquitos. Mosquitos reproduce at an alarming rate, and they love standing water. However, you have options to prevent this pest from becoming a part of your gardening.

Use a cover and eliminate any extra holes in your gardening setup. Your first step is to prevent their entry in the first place. Some growers use mosquito traps around the system to catch pests.

However, one safe option is to have your garden staged indoors or use a fiberglass window screen.

Big or small

If you have a small Kratky method garden, the labor is relatively small. However, if you have a more extensive growing system, you must be aware of the time you spend.

For instance, if you have several tanks or containers, be sure to measure your nutrient solution and pH levels all at once. Otherwise, you face having to go back and forth to get the levels just right in each individual container.

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Also, be aware the tanks must be cleaned after each growing cycle. An extensive setup equals plenty of labor. On the other hand, a small indoor garden is easier to manage, especially in the beginning.

For some, the extra time is worth it in the end. Others might consider starting smaller and working their way up to elaborate Kratky hydroponic gardens.

Temperature

The ideal temperature range for this method of growing is between 65 and 80 degrees Farenheight.

If you have your hydroponics set up inside, the temperature is probably not an issue.

However, temperature variables may matter in an outdoor setup where there are swinging temperatures during the growing season.

Ready, Set, Grow

The Kratky method is an excellent option for those who wish to garden but do not want to deal with all that comes with gardening in the dirt.

With the Kratky method, gardeners set up a container filled with water. The water has a specific level of nutrients added, and the plants feed off the water as they grow.

The plants or seeds go in a growing medium inside net pots. The net pots are then fitted in a hole in the lid of the reservoir.

Once it is all ready, gardeners leave it alone and let the garden grow.

Recommended Read: How to Grow Hydroponic Strawberries | Planting From Seeds or Seedlings Indoors

As the plants use the water, the water level decreases. As the water level decreases, the roots continue to reach for the water, but there is now an oxygen-rich air gap that creates healthy roots.

When the growing cycle is over, gardeners harvest the food and start the growing process over again.

Typically, green leafy vegetables and some herbs grow best in this type of hydroponic gardening. However, other plants do well, too.

There are very few hassles with the Kratky method, but there are some. The temperature needs consistency, and hydroponic gardeners must take time to avoid mosquitos.

However, overall this method of hydroponic gardening is easy even for a beginner.

What does your Kratky method garden look like? Let us know in the comments.


A teacher by trade, Victoria Caine splits her free time between freelance writing, her camping blog, and (frantically) guiding her teenagers into becoming functional adults. Get more gardening and growing advice from Victoria at Grow Wherever.

Last update on 2021-06-15 at 20:03 / Affiliate links / Images from Amazon Product Advertising API