How to transfer plants growing in soil to the Kratky Hydroponic Method System?

Robert C. Newkirk, Jr.

April 01, 2021

How to transfer plants growing in soil to the Kratky Hydroponic Method System?

Transfer plants from soil to a hydroponic system is pretty straight and forward. There are a couple of things that you will need to make the transfer go smoothly. First, you need to decide how big of a container you will need to grow your plants successfully. Remember that the Kratky method of hydroponics is you set it and forget it. I mean by this that the container of nutrients should hold enough plant food to take you through the whole growing cycle from start to finish. You should never add or refill nutrients during any part of the growing cycle. The reason for this is that as the roots of your plant grow, they develop air roots. These roots give you plant oxygen as the nutrients in your reservoir begin to deplete. If you add nutrients to your reservoir during the growth cycle, you can drown the plant. For this reason, I do not recommend adding or changing your nutrients during the growth of your plant.

That is why it is crucial to select a container big enough to get you through the growth cycle. One of my rules that I have developed is that you will need one gallon of water with nutrients for every foot your plant grows. For example, if you are growing tomatoes and on the back of the tomato, the seed pack states that your plant will reach five feet in height, then you should use a container that will hold at least five gallons of water with nutrients. Sometimes I will go beyond this rule and add a couple of extra gallons. A five to seven-gallon container would probably be better.

After choosing the right size container with a lid for the job, you will need a net cup or a plastic cup or a yogurt cup with holes drilled in it so that the roots can reach the nutrients in your reservoir. You will need some growing medium to support your plant as it grows. You can use hydroton clay pebbles, Rockwool, coconut coir, sand, peat moss, woodchips, stones, perlite, or anything you would like to use.

Remove the plant that is growing in soil and be careful not to damage the roots. Rinse the roots under running water to remove the soil from the roots. You could also use a bucket filled part-way with water and rinse the dirt off the roots. Once the soil is removed from the plant, the plant is ready to be planted into your net cup or plastic cup with holes drilled into it. Place the plant in the net cup with the roots touching the bottom of the net cup. Carefully add your growing medium around your plant, making sure you are not damaging the roots. Place your net cup into the hole that you drilled into the lid of your container. Fill the container up with water and nutrients. Make sure that the net cup sits into the water approximately sixteen of an inch. Place your plant under a grow light or in a windowsill or outside in the fabulous sunshine. Congratulations, you have just successfully transplanted a plant growing in soil into a Kratky hydroponic system!