Looking for a very low cost, low maintenance hydroponics method? The Kratky method is about as simple as it gets for aspiring hydroponic enthusiasts.
The Kratky Method
The Kratky method is a passive hydroponic system which means that it doesn’t require any electricity or pumps to operate.
A Kratky setup consists of the following:
- A suitable container, such as a mason jar
- Nutrient solution for the plant (water with a plant fertilizer)
- A net pot (a small pot to support plant roots) that will hold the plant suspended above the nutrient solution.
- Growing medium where the plant will grow, such as clay pebbles or coco coir
Notice in the picture of the jar that as the plant grows, its roots reach down into the solution to absorb the nutrients and water needed to thrive.
Also note that although you don’t necessarily require a net pot, you’ll need something to support the plant when it is small and as it matures.
I prefer using a 3 inch net pot which fits perfectly into the top of wide mouth Ball Mason Jars. 3 inch net pots only cost a dollar or so each.
There are numerous household options available if you don’t want to buy net pots, such as store-bought leftover yogurt containers or Styrofoam cups.
Sometimes with leggy houseplants, I will even let the foliage support itself on the edge of the jar.
Looking to learn about other hydroponics systems. Click here!
Key Features of the Kratky Method
The key feature of the Kratky method is that the amount of nutrient solution you start with should be adequate for the life of the plant. With Kratky, the solution level decreases as the plant absorbs the nutrients thereby creating an air gap between the solution and the bottom of the net pot.
This air gap provides the plant with the oxygen it needs to survive. You can see this at work in the picture above.
And, if you’ve read our other article linked just above on the different types of hydroponic systems, you’ll recall most other systems require water pumps, air pumps, and/or timers.
Kratky Container Options
You can choose from a variety of options for containers. I’ve experimented with cola cans, mason jars, and vases.
Many people use 5-gallon buckets for supporting larger plants, such as peppers. I’ve even seen someone using an aquarium!
When choosing a container for the Kratky method, it is important to ensure that it’s food safe. In other words, don’t use a container that has held chemicals or other potentially toxic materials!
It’s also a good idea to choose a container with a lid as this can help to reduce evaporation and keep the nutrient solution clean. Obviously, you’ll need to cut a hole in the top of the lid for the net pot and plant.
The size of the container you require will depend on the plants you’ll grow. You’ll want to use a container that can comfortably hold the roots of the plant and nutrient solution.
Give the roots plenty of room to grow without being constrained.
Types of Plants for Kratky
The Kratky method is ideal for growing small plants with short growth cycles, such as lettuce and herbs. I also personally use it for growing houseplants, such as Golden Pothos.
I’ve included a picture of one of my houseplants. Growing in water really adds visual interest to any room!
However, bear in mind if you use Kratky for larger plants, or plants with longer growth cycles, you will likely have to replace the nutrient solution as it is consumed by the plant as it matures. Some larger plants are very thirsty!
Comparing Kratky to Deep Water Culture (DWC)
Deep Water Culture (DWC) is another popular hydroponic system.
The primary difference between Kratky and DWC is that a DWC system includes an air pump and air stone to oxygenate the water. Roots of plants grown in Kratky receive oxygen via the exposed roots that hang down into the nutrient solution.
The fact DWC includes the air pump which constantly runs makes it slightly more complicated.
Summary
Overall, the Kratky method is a great option for hobbyists and small-scale growers who want to experiment with hydroponic gardening without investing in expensive equipment.
Its cost, ease of setup, and low maintenance really can’t be beaten. Give it a try, and comment below to tell us how it went!
Ready to increase your knowledge of hydroponics? Be sure to check out our other articles on managing pH and the best produce to grow hydroponically.
