Four Important Facts You Should Know About the Kratky Growing Method!

By Robert C. Newkirk, Jr.

December 30, 2020

Herbs and Leafy greens grow well with Kratky method hydroponics.

Using the Kratky Gro method, herbs and Leafy greens are some of the best plants to grow. Most herbs and leafy greens are tiny plants that grow extremely fast using this hydroponic method. Due to its fast growth rate and high yield, Romaine Lettuce is one of the easiest plants to grow with Kratky hydroponics. Spinach and Basil are other leafy greens that grow exceptionally well in a simple Kratky Gro setup. Kratky Gro recommends starting with leafy greens and herbs when starting with the Kratky method. Once you see how well this method works for you, we suggest it is time to move on to other plants.

Setting Up Your System is Essential to Block Out the Light.

Keeping the light out of your reservoir is one of the most critical steps. Light and heat can cause algae to grow in nutrients. Algae in your reservoir become a nuisance in high quantities as it reduces the available oxygen in the water and utilizes the nutrients in the solution. Algae will affect the growth of your plants. It is also unsightly ugly. Keep your reservoir blackout or covered to prevent unattractive algae growth.

The Kratky Gro Method is Considered a Passive Form of Hydroponics.

You should consider a passive way to grow because it doesn't require pumps to circulate water and nutrients. Kratky Gro method of hydroponics relies on a container of hydroponic nutrients and air. Electricity, pumps, air stones, and wicks are not required. It is not necessary to change the nutrients weekly, nor is there a concern about rejuvenating oxygen for the plants.

As the plant grows, the water level drops, creating air space for the roots to receive oxygen. By the time the plant is ready for harvest, the water that has the nutrient solution is nearly used up. No need for you to replenish your nutrient solution, but it is essential that you choose the right size container that will be big enough to handle the whole growing process from beginning to end. Usually, a one-gallon container will be efficient enough to handle a leafy green like romaine lettuce or spinach. You only need to calculate the amount of nutrient solution the plants require to fill the container only once.

After the plant is harvested, you should clean your container so it can be used again for another plant. The passive way to grow your favorite is what I consider to be the set it and forget it way to grow. Because if you have done everything correctly, you should not have to maintain your plant through its growing cycle.

Kratky Hydroponics Requires Eight Basic Supplies, Six if Using a Pool Noodle!

The Kratky Gro method is inexpensive and requires only the following supplies.

A Container: Depending on the size of the plant, you can start with something as small as a one-gallon container minimum. Many people use mason jars, but through my experience, you need to fill the nutrients regularly, which, if not done correctly, can drown your plant. Many gardeners opt for something more significant, such as a 5-gallon bucket. Large-scale production will require more nutrients.

A Lid: The lid is essential in preventing evaporation of the nutrient solution and helps keep light out of your nutrient solution. The lid helps support your net cup or plastic cup with holes drilled in it. The lid helps to support the plant above the water. You can be creative if you do not have a net or a plastic cup. I have used a pool noodle to support the plant. If you use a pool noodle, growing medium or the net cup will not be required because the pool noodle will support your plant.

Net pots. Plastic webbed, shape cups with holes in the bottom and sides allow the nutrients to reach the plant's roots. Some say that net cups are essential to successfully growing plants hydroponically, but as I mentioned above, a pool noodle will do the trick and lower the cost.

Growing medium: There are many growing mediums. Some are better than others. I prefer clay pebbles, which are round pieces of heat-expanded clay that give your plant the needed support; it helps to give your plant the oxygen it needs and are reusable. You can use any type you want, like coconut fiber (a sustainable, organic, biodegradable medium made from shredding the inner pith of coconut husks), Rockwool (or stone wool, which is a porous material made of spun basalt rock fibers), or perlite (a lightweight volcanic rock).

Hydroponic fertilizer: Nutrients are needed for the Kratky method or any hydroponic. Nutrients are the same as fertilizer, which comes in liquid or powder form. Hundreds or even thousands of different brands and types are available. My favorite is General Hydroponic. It was one of the ones I used when starting, and I have had many successful grows over the years. I have tried others, but I always resort back to General Hydroponics.

Water: Some good old H2o for the nutrients. Spring water, Distilled water, or good old Tap Water is all good.

Air: Your plant needs oxygen to breathe.

Light: You can use artificial lighting or natural sunlight. I have had success with both types.