Growing food is becoming a priority for more and more people. Homegrown food tastes better, is healthier, and is a lot more affordable. However, you might not be so lucky to own land or the land you own is frozen half of the year. Growing food the Kratky Hydroponics Way is one of many ways to grow food without land. If you are interested in hydroponics but are not ready to invest in a complex setup just yet, then the Kratky method might be the one you want to explore.
What is the Kratky hydroponic method?
B. A. Kratky from the University of Hawaii discovered this non-circulating hydroponic growing method that does not require any pump or air stones and no electricity at all.
A plant needs light, water, nutrients, and oxygen to grow. The Kratky method provides all this in a very simple way. You add water with all the mineral solution needed into a container with a net pot and some rock wool (or any growing medium of your choice), plant your seed, and let it grow. See how to plant a hydroponics garden here.
As the plant grows, it will “drink” the water. The gap will be filled with moist air, providing the roots with oxygen.
By the time the plant used up all the water, it is ready to be harvested. For plants that need longer to mature, just keep the container filled about half full. We will talk about an example later.
What will you need to grow food the Kratky hydroponics way?
-A container to grow in. Any watertight container will do. It is good to choose a container that does not let light through to prevent algae from growing (see picture above, the water is green because of algae).
The container can be of any size for as many plants as you want to grow, meaning if you want to grow a small plant and just one you choose a small container, if you want to grow a dozen plants you obviously will need a bigger container. Also, for the Kratky method, all the plants in one container have to be of the same variety and at the same stage of growth.
For example, one lettuce needs, give or take 1 gallon of water with a nutrient solution in its lifespan. A milk jug would work for it. If you want to grow 3 lettuce plants, set and forget till they are done, you will need a 3-gallon container. Or, as I explain below, you can also use a smaller container and refill it.
Bigger plans will need more nutrient solution, a pail, a rubber box, or whatever you have on hand can be turned into a growing container. It is just like container gardening, except these containers need to be able to hold liquid. I also like to use a nice potting pot, add a lid and grow in there, looks decorative too.
An opening in the plastic lid can easily be cut out to fit the net pot. Alternatively, a lid can be cut out of styrofoam and the bucket wrapped in black material to prevent light to come through (See picture below).
-A Mesh Net Pot. We like the two-inch in diameter, but you can get them in different sizes.
-Growing medium, we use Rockwool.
-A hydroponic solution, we like the General Hydroponics MaxiGro. It is simple to use and works for all kinds of green plants. Read more about it below.
–Ph Control Kit, to ensure the proper balance of nutrient solution.
-Seeds. Read more below on what to grow in the Kratky method.
You can use whatever nutrients brand you want or is available at your local supplier. We prefer dry concentrated nutrients. General Hydroponics MaxiGro is a simple product to start and what we use. The green is for green plants like lettuce and also to start fruit-bearing plants like cucumbers.
General Hydroponics Flora Grow, Bloom, Micro Combo Fertilizer set is a liquid solution for all stages of growth.
General Hydroponics Ph Control Kit helps you to keep the PH at 5.5-6.5.
What to grow the Kratky hydroponics way
The simplest and most effective plant for the Kratky hydroponics method is lettuce. You need one gallon of the solution and can plant and forget it till harvesting time. But lettuce is not the only plant that can be grown. Any above-ground plant can technically be grown the Kratky hydroponics way.
Depending on the size of the container, it might not be all that set and forget. Bigger plants need to be refilled, making sure that the container stays about half full, allowing the roots to have lots of oxygen.
In our experience, the Kratky method works well for fast-growing plants. It works great for cucumbers, they grow fast, produce and die back, now you can start new once. Also if you want to grow tomatoes, choose a determinate, early variety.
Here a Kratky hydroponics cabbage plant in our laundry room window. It was more fun than food, to be honest, but sometimes an experiment is worth it.
Here Kratky method basil in our kitchen window. We started the basil from a cutting, and it grows in a recycled glass jar, that stays in an ornamental hanging pot. Kratky hydroponic can be nice, too ;).
Here a tomato trial. So far we are impressed. However, growing tomatoes might be better in aeroponic than in a non-circulating hydroponic. Still, if that is all you can afford, go for it. In 12 weeks the plant shows remarkable growth and has set fruit, too.
For fruit-bearing plants like tomatoes, you can start with a smaller container and fill it with a solution using the green fertilizer.
Transfer it into a bigger container when the plant outgrows the small one, and start adding the fruit fertilizer. Remember the plant need oxygen, so if you want to keep growing without any electricity just the Kratky way, make sure the roots are half in the air, meaning the container is not filled to the top with the solution water blend.
Keep refilling the container with water or nutrient solution as needed always making sure there is air, and water solution available.
Start growing food the Kratky hydroponics way today! It is a simple and fun container gardening method suited for off-the-grid and water-saving growing. As all growing, it starts with planting, read also Planting a Hydroponic Garden.
Grow an indoor edible garden
Kratky hydroponic is a great way to grow food indoors in any weather. Read more about growing food indoors: