The Kratky Method – The Pros, The Cons, and The Lettuce

Facebook is a crazy place!

Recently a good friend of mine decided to try his hand at gardening and reached out to me on Facebook to ask me for advice. While I’m glad he’s joining our side, it surprised me. A couple of years ago he was the typical beer-toting man’s man who would scoff at my gardenias. But he has since changed his tune!

He proudly claims he saw a video of a girl making a pizza from scratch with home-made ingredients and is going to do the same. I applaud his ambition. I guess it’s a change. It’s a nice change, actually!

I sat down with him and we began talking. We quickly began talking about hydroponics. I began raving on about lettuce and the Kratky method.

So, what is The Kratky Method?

The Kratky method is the simplest and easiest way to grow more leafy greens than you and an army of rabbits can handle. It’s simple to set up. It’ll teach you the basics. You can even make your builds out of things lying around the house. Best of all, after you have it set up, you won’t have to touch it again until you’re ready to harvest.

In other words, it’s the best way to get started in hydroponics. And a certain someone understood that very well.

The Man Behind The Lettuce: B.A. Kratky

Source: The Prepared Page

The year is 1993. The sun is shining, the air is dry, the lettuce is growing, and the waves are roaring. At the University of Hawaii, a young researcher named B.A. Kratky makes a great discovery. It turns out, you don’t need an air pump to make a hydroponic system work. 

In fact, you don’t even need to check on it.

The roots do all the work here. In a typical hydroponic system, there needs to be a source of oxygen for the plant to stay healthy as it grows. This is usually an air pump. What Kratky found out was that if you suspend the roots in the right mineral solution and leave it alone, the air pump was not necessary.

It goes like this, as the plant consumes the water and the water levels begin to decrease. A pocket of air begins to form between the surface of the water and the nest of the plant. The roots will begin to extract oxygen from the pocket of air while the tips submerged in the water send the nutrients up to the plant. This is the key idea. This is what separates Kratky from the Deep Water Culture (DWC) method. 

Cool, right?

So cool he went on to secure 2 patents.

Did I mention it also yielded 24% more growth on his crops?

Let’s get a little more in-depth on that…

What’s Happening Inside?

It all starts with a baby seedling. Maybe about 2-3 weeks old. You put him in a net pot or any container with enough space for the roots to grow out. You fill the container with water until the net pot is submerged by around 2 inches of water. Add the appropriate nutrient solutions to the water for each plant and close the system.

You have to cover the container so light doesn’t get in, otherwise, algae will begin to grow on the roots. While they don’t directly affect the roots themselves, they do compete for the nutrients and oxygen in the system and can hinder plant growth. Thus, a sheet of aluminum is usually used to surround the container. You can also spray paint the container black, wrap it in newspaper, etc. Anything that blocks the light from your reservoir.

And thus, the plant begins to grow. The Kratky method is probably the simplest out there, although it does have its ups and downs like any other.

The Pros

Just as Effective – Test after test has been conducted on the efficacy of different hydroponic builds and Kratky is always on top in crop yield.

Dead Simple to Maintain – It’s as simple as it gets. Make sure you get the nutrient solution right and you’re good to go. You might want to test the waters around the second week to make sure everything is fine but that’s just good fortune.

Easy and Cheap to Set Up – Due to the flexible nature of the idea, it can be made with materials lying around the house. Just make sure the seedling has lots of room for the roots to grow. Get a dark material so light doesn’t seep through. No algae allowed!

Excellent Gifts – There’s something incredibly personal about gifting a plant. The hands-off nature makes it perfect for busy people.

Good for Beginners – The Kratky method will have you go through the essentials of a good hydroponic build.

Good for The Kids – Since it’s so simple, you can build it for your kids or a classroom in a single day and let the kids watch the plant grow! They will grow especially fond of it knowing they helped put it together.

Great for hobbyists with little time – Let’s face it. Gardening can be a time-consuming task. Electronic failure or a missed watering day could mean the end of your little plant. And when work is always getting in the way, the fruits of labor seem near unattainable. The Kratky Method is great as it doesn’t need to be checked often.

Make Some Extra Cash – Once you have a setup going, you can expand and sell your crops to local restaurants and farmers’ markets. Anything home-grown (and especially organic) will usually fetch a premium.

YOU GET TO SEE ROOTS IN THE AIR – Probably one of my favorite things about The Kratky Method affords you the ability to actually see the beautiful root system that usually lies hidden in the dirt.

Source: Uponics

The Cons

Not That Great for Larger Plants – While the system is great due to how low maintenance it is, bigger plants need much bigger containers.

Needs to Be Surrounded by Aluminum Foil (or some other covering) – I know, I just got done talking about the beautiful root system. The issue at play here is that the roots’ exposure to light promotes the growth of algae which can “hog” the nutrients from your liquid plant food. You want all of that goodness to promote your plant’s growth – not the algae.

Make Sure That Lid Is On Tight – You fought long and hard to make sure the water inside the container is just perfect for your new crop. It’d be a shame if it were to rain and all that contaminated water got inside your container, now wouldn’t it? Or if an insect managed to crawl inside and wreaked your delicate root system.

You got one shot to do it right – So get it right – If you don’t get the pH right the first time and don’t check on the system afterward, you could be dooming your plant from the beginning. 

Individual testing is required, thus large-scale production can get tiresome. Testing the water for each container becomes inefficient at larger scales. While some farmers have managed to make larger systems profitable, most tend to switch to electric systems for more control.

In Conclusion

All in all, The Kratky method will always be the first thing I recommend to new people interested in gardening. It’s very simple but can feel incredibly rewarding for someone just starting off. It’s one of my favorites and it’s a nice little gift when I have a 4-liter bottle laying around. If you like this, you’re gonna have a blast with everything else there is to know.