Mason Jar Hydroponics

Hydroponics is a powerful technique for cultivating plants. It is defined by not using soil but suspending the roots of a plant in a nutrient solution which allows for very precise nutrition of the plant and a high uptake through the roots which result in faster growing and higher yield.

One of the big drawbacks of hydroponics is that depending on the selected type of hydroponics, it can get pretty complicated in comparison to planting a plant in a bucket full of soil.

To make it more easy for beginners, I'm going to present the Kratky method, which basically doesn't need anything more than the plant, a container like a mason jar and the nutrient solution.

No pumps, no timers, no moving parts, nothing. Awesome.

Presented in 2009 by Bernard Kratky in the journal Acta Horticulturae, it is a rather new method of hydroponics.

The important aspect is the only the tips of the roots are suspended to allow a proper oxygenation of the upper part of the roots.

The plant uses the water and the nutrients which causes the water level to go down. As the roots grow at the same time, the tips still stay in the water during the whole process. It depends on the plant of course but it takes around a month.

Mason jar: It is better if it is broader, as the water level will lower more slowly but pretty much anything works, as long as the roots fit. A glass jar is perfect, as it allows to inspect the roots.

A clone or a seed: In this example I'm using a basil clone that I did myself (see for example https://www.youtube.com/watch?v=OJrTPkM8rRE). You can also just plant a seed in the package, this will take a little bit longer.

Some medium like coco coir or mineral wool: I love coco coir but both work.

A nutrient solution:This is the only thing where you can't really take shortcuts. The nutrient solution is a science in itself, if you want to know more about it, there are a lot of great resources like https://smartgardenguide.com/hydroponic-nutrient-...

For the beginning I would seriously recommend a premade mixture, as it takes a lot of practice to mix your own.

There mixtures in liquid form and some the come in granulate form and are meant to be dissolved in some water.

Both work just fine. Look at your favourite online or real life retailer for hydroponic nutrient.

One word on measuring the nutrient solutions. As a hobbyist you would only measure pH value, which influences the uptake rates of the roots and the EC or TDS value which measures the nutrient concentration in the fluid.

Stay away from the cheap measuring devices of amazon or ebay, they simply don't work.

You also don't need the expensive electronic ones unless you want to grow something commercially. For the beginning if you use the mixtures according to the manufacturer you should be fine.

I myself am currently using a pH testkit which is used for aquascaping and is pretty precise and cheap. It is a little bit of a hassle, but as long as you're just experimenting its more than enough.

Some paper or aluminum foil to wrap the jar: Roots don't like light.

A net pot: See next step to see how I improvise one, otherwise you'll find them on any major retailer.

First you have to make a package of the clone or the seed and the medium. If you want to get fancy you can use a commercially available net pot, but this is a great chance for upcycling, so I used an empty yoghurt crème fraîche pot which you can cut up using a scissor.

Some people also use textiles like an old sock or something but I never tried this. Again, if you are successful with this, tell us in the comments.

Fill the net pot with your medium of choice and put in the plant/seed.

Prepare the nutrient solution as indicated by the manufacturer. Fill the jar with it so far that it barely touches the bottom of the package. This way it will soak up just a little bit of the solution.

To prevent the water in the nutrient solution to evaporate to fast, you need to seal the opening.

If you want something fancy together with a commercial net pot, just search for aeroponic neoprene collar. Otherwise, just use some cling foil.

The roots don't like light. Some people paint the mason jar, some people wrap aluminum foil around. I just wrap it in thick paper.

This is the result after 10 days. Some part of the nutrient solution was used up and the roots followed it.

This method is perfect for leafy greens like basil or lettuce.

Anything with fruit will prefer other nutrients when blooming. For this you would want another hydroponics technique which would be more suitable.

Basil is one of the easiest plants to grow, after this you should try some lettuce!