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How to make your own low-tech vertical farm

The ingenious low-cost vertical farms of Willem Van Cotthem are within reach of everybody.

Image: Low-tech vertical farming. Image: Willem Van Cotthem.
Image: Low-tech vertical farming. Image: Willem Van Cotthem.
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Vertical farming has become a popular idea, but what is mostly forgotten is that the energy required for the operation and construction of vertical farms largely negates the ecological advantages. This also applies to small-scale systems, like those of Philips (a concept) or Inka Biospheric Solutions (a product).

A while ago two New Yorkers made headlines with their “Window farms”, described as a kind of low-tech indoor vertical farming system. Upon a closer look, however, I found the method to be rather high-tech and cumbersome, in spite of the use of plastic bottles. A window farm is based on hydroponics, it makes use of lamps, pumps and electricity, it still requires you to buy quite a lot of new stuff, and the whole thing would surely come crashing down if I were to install it.

The Belgian professor Willem Van Cotthem seems to have designed a a-do-it-ourselves-guide vertical kitchen garden system that truly deserves the low-tech label. On his blog, “Container gardening”, he explains how to transform normal plastic bottles into efficient containers (and a container rack) for growing all kinds of plants, even young trees (to be transplanted when reaching sufficient height). The beauty is that the water supply can be automated without the use of electricity, and that his way of installing a vertical garden looks much simpler and sturdier.

Willem Van Cotthem is a researcher specializing in combating desertification, an occupation he describes on his other blog, “Desertification”. Here lies the origin of his low-cost, low-tech methods to grow plants and crops. Van Cotthem manages to grow vegetables and fruits in the middle of the desert with minimal water (pictures). Apart from the methods using plastic bottles described above, he also uses mini-greenhouses made of trash (yoghurt pots, plastic bags) to produce vegetable and (fruit) tree seedlings. All systems can be used both indoors and outdoors.

What all these methods have in common, is that they hardly use any water, basically by minimizing evaporation. Moreover, because of the low cost (using 100 percent trash), the systems can be used even by the poorest of people. Plastic rubbish is, unfortunately, everywhere. Van Cotthem’s blogs can be a bit chaotic to navigate, but his work is definitely worth a look.

Thanks to Theo Lalleman for the tip.


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Charlie Parker

diy, do-it-yourself, gardening, window farms, vertical farmings, vertical farm

“I can’t think of any technology that addresses more urgent issues than Valcent’s vertical farming system”, says RFK Jr


It’s a great concept. However, I can’t find any actual tutorials from Van Cottem for creating a vertical, urban indoor garden.

For apartment renters, we’d need something easy to install in a variety of different wall types, something that would not have floating columns of water (likely to break, ruin the carpet, and take away our entire security deposit), and something easy to install and take down when moving. In first world urban areas, materials and even cost of such a system aren’t the problemit’s time, technology, space, and cleanliness.

Kris De Decker

Interesting blog you have, Mark

levi civita

Plastic containers are problematic due to their chemical make up.

Use earthenware when practical.

Willem Van Cotthem

See - Dear Kris, I just read the article above again : “How to make your own low-tech vertical farm”. Did I miss the word TerraCottem somewhere in the text ? Did you (the author of that text) made any allusion on my former scientific work on soil conditioners ?

Let us not mix apples and lemons. This idea of growing plants in plastic bottles on a vertical rack is only one of the results of my continuous efforts to help hungry people in the drylands to fresh food with a minimum of water.

I remain open to any discussion on TerraCottem, but not in your excellent Low-Tech Magazine, because that soil conditioner is most certainly NOT LOW-TECH.


If you are looking for a source of containers I recommend visiting your local restaurants and ask them for their empty glass jars. Some (such as the ones that hold pickles or sauces) hold more than 3 litres (0.8 Us Gal).

plastic soil?

The containers in Professor Van Cotthem’s may not be low-tech at all but they merit something for the reuse of otherwise harmful trash. That’s the least problem. What’s the story with this trademark TerraCottem soil supplement??? The professor invented it, so his promotion of his proprietary product is understandable, but there’s nothing low-tech about it. This product is described on as “consisting of a proprietary mixture each [sic.] of more than twenty components from different groups…” and the product’s “crosslinked hydroabsorbent polymers of acrylamide and acrylic acid…” that’s before saying anything about this medium’s “carrier materials.”

I don’t understand half of this description. I only understand enough to say this is a high-tech product that one can only buy, not make at home.

Additionally, what with the polymer talk it sounds like plastic soil. Surely that’s far worse and dangerous than the mere containers.

Does this plastic soil degrade? How long does that take? What are the fertilizers in it? More petrochemicals?

kris de decker

“What’s the story with this trademark TerraCottem soil supplement???”

I don’t get that either. That’s why I left it out.

Mark Ridsdill Smith

Really interested to read about this. Is there anyone out there who has built one of these and is using it to grow food? Or plans to build one? If so, I’d love to hear about your experiences.

These bottle containers are clearly designed for food growing in countries with little water and I’d have thought the bottles are rather small (and fiddly) for productive food growing elsewhere? Other ideas like like this look more fit for for purpose:

Mark (

G L Bansal

The idea is great and makes sense for growing freshies and vegies at home scale in little containers. It is more of hype than reality in use of plastics as pointed out. Sometimes ago, there was controversy over use of plastics in microwave ovens and there were divergent views. I think people may be affected more for the want of freshies and nutritional deficiencies than plastics. The produce is well balanced and without pesticides.


A small fish tank air pump could be used to slowly lift the water to the top. Here is an example.


Actually this year starting with window farming, I didn’t get into vertical farming yet, but having some success in sprouting and growing different kinds of peppers (bell, Chinese, lombok). The problem with vertical farming is the noisy aquarium pump and the fact that it wouldn’t do without electricity. The VanCottem setup inspired me to think of a passive pump system, bio clock like. Plants don’t only grow, but do become heavier while growing, and do need more nutrients. Actually the pump should work slow in the beginning and work harder (and make more noise) when it gets more leaf. A classic clockwork has a counter weight that actually makes the clockwork work (timed). A plant with a certain start-up weight could do as a counter weight, driving a clockwork like mechanical pump while growing upwards, becoming heavier and leafier. It would mean having only one plant vertically, and several horizontal. The pump would be a silent one, without the use of electricity.


Actually, the roots are very sensitive to light. So the plastic bootles should be painted black.