Hydroponic Bonsai or Bonchis? Plans for the Net Cups

One issue with growing bonsai’s in Kuwait is sourcing appropriate soil substrates. It’s easy to get normal potting soil, and even perlite, but anything specialty like bonsai requirements gets a bit harder to shop for… After frustrating shopping trip after trip, I gave up… I thought I would never be able to grow bonsai’s. Until my husband asked why not grow bonsais hydroponically?

If you read my blog a lot, you probably realise that I am a big fan of hydroponics. Do you over water or under water your plants a lot? Hydroponics is for you. Do you have issues with bugs and pests? Hydroponics can be good for you. Forgot to add fertiliser every few weeks? Hydroponics is easy! It is honestly easier growing in only water than it is growing plants in soil.

But can bonsai’s be even grown hydroponically? Many bonsai enthusiasts and professionals will balance the growth of leaves and foliage with that of roots. The Nebari or root flare is considered a vital aspect of bonsai growth, getting the base of the tree to match the appearance of the larger trees as much as possible.

Nebari Photo, Courtesy of Bonsai Tree Paradise

Obviously when growing in net cups that becomes a problem; the plastic at the edge of the cup restricts the growth of the plant and forces it downwards. Could we solve that problem?

My first idea was to increase the width of the net cup. Net cups are most common in 2-3inch sizes (5-7.5cm). It is possible to purchase larger cups up to 6inches (15.3cm). However cups at that width also tend to be quite deep. Such a large feature of bonsai’s is that the root base is wide and shallow.

Could I modify a pre-bought net cup to be shallow? I started wandering if I could make my own net cups in some way. I also had the issue of how I would grow these plants long term. My black painted Sortera boxes weren’t that pretty to look at, and were somewhat large for single plants.

Ikea Sockerbit Bucket
Ikea Sockerbit Bucket

Since I am growing quite a number of bonchi’s I want to make sure my pots match (OCD a little?). I have quite a number of Ikea Nypon pots, and they are quite easy to buy.

But the pot doesn’t include a lid that I could attach a net cup to.

Thankfully… my husband and I ordered a 3D printer recently! Basically all my problems solved. Okay so I agreed to order the expensive 3D printer since we have more use cases for it now… or did I ask for it…

Either way, I had to start designing a lid for the pot that could be printed. I had some Wishlist features already. I knew that I wanted:

  • A watering hole, as lifting the plant or lid on a regular basis was risky and annoying. This hole would also need a cover to block light from entering the pot.
  • As wide of a net cup as possible, whilst ideally keeping it somewhat shallow.
  • A net cup that was ideally attached to the lid, to prevent the plant from toppling over because of uneven weight.
  • An optional water level meter – since it won’t be so easy to look inside to see how high or low the water level is.
Mockup Hydroponic Bonsai Lid with Net Cup Design In Blender

Since I am familiar with the 3D program Blender, I immediately started mocking up a basic concept. The giant hole is where the net cup would be (not modelled). The stick/pole in the top right is the water level meter – most 3D printed materials will float, and I could always attach something like foam at the bottom for extra buoyancy. Finally we have the watering hole and it’s own cover.

I wanted the design to look like it was built specifically for this pot (which I guess it is). So I maximised the size of the net cup area by creating it in a C shape. I need space to water the plant, and thus a watering hole, of course. The water hole itself was rather tight, at only about 2cm wide. To increase that space I made it slightly oval shaped. Everything about this design was rounded shapes.

The problem with this design is it’s not very scalable. The Nypon pots are sold in 3 sizes – 12, 15 and 24cm. And what if I wanted to buy other pots? I didn’t want the tedious task of modelling the entire design over and over again. So I needed to learn Parametric Modelling, and a program that handles that well is Autodesk Fusion 360.

Design MK1 in Fusion 360

It’s far from finished, but here is my current mockup in Fusion 360. The benefit is that Fusion 360 can act entirely upon parameters. A user can input that their pot is 12cm in size, or alternatively say their pot is 24cm in size, and everything in the design will change and update appropriately.