[CHALLENGE] Upcycled sub-irrigation planters for container gardening

##Who are we
Hi! Despite being a science hacker and a biologist, I’m a very bad gardener. I really like the idea of growing vegetables and herbs in containers on my balcony, but I always get too busy and forget to water them. Maybe you also have the same problem. This is a challenge to hack sustainable DIY solutions.

##Short Description
We’re going to design and build sub-irrigation planters (SIPs) for container gardening from recycled trash.

###What is a sub-irrigation planter?
Water is taken up into the soil as needed by wicking capillary action from a reservoir below. The steady supply is better for the plants, AND the bigger the reservoir, the less often you have to water them. There are lots of different designs to be found on the internet (see also the links in the resources section below).

###What do we need?
I’ll bring tools. Instead of buying materials to make these planters we are going to convert existing planters and/or upcycle them from trash. We’ll be looking for things like this:


Different non-biodegradable materials that can create a barrier to hold the soil above the sub-irrigation reservoir. LOTS of plastic bottles, also to make watering tubes:

If you have stuff like this at home, please bring it with you. Otherwise, we will go on a trash-gathering expedition around the neighbourhood (bring a bike!), and maybe also call in at Kunst-Stoffe Materiallager if we get stuck.

To be determined. I’d suggest one of the following (slight preference for Saturday):

  • Saturday, 13:00 Trash expedition, 14:00 visit Kunst-Stoffe (open 14:00-16h), 14:30-15:30 Build
  • Sunday, 10:30 Trash expedition, 11:30 visit Kunst Stoffe (open 11:00-13h), 12:00-13:00 Build

Some of my favourite DIY instruction for SIPs

1 Like

A couple of prototypes :slight_smile:

1 Like

Time for a little write-up… Big thanks to @dax, Ania and Stefan for joining in - it was super fun.

This worked pretty well as a challenge. A few notes:

  • It was good that I had some big containers already (thanks to the Richardplatz Sperrmüllfest) that I brought with me. These aren’t so easy to find spontaneously on the street. But there were plenty of plastic bottles to be had.
  • Hunting useful trash makes you see the city in a different light. The streets of Neukölln are rich with building materials for the right projects. Because we were looking for rather specific stuff I’d recommend taking a bike.
  • melting holes in plastic bottles with a soldering iron is a very relaxing and meditative experience.



THE RESULTS :slight_smile: :

I guess we didn’t do so well with documentation for all the designs… but here’s some more details about the one I made (the blue one). It uses several plastic bottles to save space for the water reservoir. All have lots of holes melted in them. One of them also fits by the neck through a hole in the side of the main container, making an overflow at a reasonable height (you can see it in the picture above).

You’ll need to allow some of the soil to fall down into the water reservoir as a continuous column to allow for water to be sucked up by capillary action, but really you want to minimise this as much as possible. Ania’s discovery was that you can crush the plastic bottles if you need to to help fill up the space.

I planted up some supermarket parsley and added it to our growing roof garden at Lacuna Lab. Fingers crossed it likes its new home :slight_smile:

1 Like

The design reminds me on “Sören” - basically the same idea ? – an irrigation system that was shared a few years back Open Source. Here is their video (german)

And 2 links:

Hey Lars!
Thanks - I had a look through their website and whole project - very nice. Do you know if they’re still active?

For my next project I’m thinking of building this:

It’s really looks like the nicest passive, vertical sub-irrigation concept, with super-standard parts, though unfortunately only partly upcycled. I was thinking a lot about using a ballcock to control water fed from a large reservoir, but this does it in a much simpler way.
Another of the important design features is that all the standing water is enclosed in this system - I’m starting to appreciate how important that is now I’m completely invaded by mosquitos at home. I wonder if that might be a weakness of the Sören system…

To update on the systems from earlier this year that were the inspiration for the challenge at OSCE days - it’s been a shitty summer, but I think they helped optimise the situation. I ended up topping up the systems virtually every day anyway (because it turns out I like gardening haha), but could happily leave them for 3 days with no adverse effects. I’ve been getting the first tomatoes and they’re fantastic :slight_smile:

1 Like

btw, this setup…

ended up growing this…

…and on a shady balcony… crazy. Seems it’s true that tomato plants really don’t need a lot of soil.

I don’t know if Sven is still active with Sören. He used to be more active for sure. But I don’t know if he is out entirely. I’ll send him this thread on FB. Maybe he has time to respond :slight_smile:

1 Like