Cactus Terrarium Desk

It was time for a new desk, and I had two things in mind:

» I wanted it to be made out of a single sheet of plywood.

» I wanted it to be a terrarium of some kind as well.

So I created a 750mm high, 800x650mm work area, slatted plywood desk with an acrylic top, so you could see small cacti and other succulents growing as you work. It's a way to incorporate greenery into a space with no footprint whatsoever, which is great for compact living.

I'd been meaning to make a terrarium of some kind, and upon doing some research I stumbled across Paige Russell's Terrarium Table which I liked very much. This became my inspiration, and the form followed the limitations and the intended function coincidentally.

The slatted construction is open, which makes it nice to sit at but also looks quite sharp and geometric. Furthermore, the blank space, as opposed to solid panels, allows light through, which can often help give the illusion of more space in a room.

Having disassembled my old desk, constructed out a sheet of 18mm plywood, I found a good opportunity to recycle a slightly damaged sheet by cutting it into slats and letting the end grain show (a style I like very much). Without further ado, here's how it's made!

» Circular saw, table saw or (possibly) bandsaw

This project involves several long, straight cuts

» Mitre saw

For cutting the strips into blocks and 45 degree cuts

» Wood glue

For the glue ups

» Brad nailer

For supporting the glue joints

And for those of us who don't have a brad nailer:

» Electric drill

For drilling pilot holes, countersinking and screwing

» Screws, length of your choice

For supporting the glue joints

This desk is constructed in two separate parts: open top box for holding plants, and a slatted plywood frame.

Everything mentioned in the next few steps will be our single 18mm thick plywood sheet (choose one without many voids if possible).

As per the cutting list above, you need 24 vertical slats, 3 foot rests, 22 brackets (these hold the enclosure), and 60 spacers for the frame. This may seem like a lot but it will just involve many repetitive cuts on the mitre saw.

Everything in the frame is made from 50mm strips so you can start by cutting length ways along the plywood sheet to give 2440 x 50mm strips. A circular saw with a guide will work nicely here.

You'll need 8 of these long strips for the vertical slats, 2 for the foot rests and a few more for the all the small spacers (cut these last ones after the enclosure is cut).

The second picture, a gif, shows how you should nest each bracket into your 8 strips for the vertical slats. After this, you'll cut the foot rests out.

After these 10 strips are done, cut out the enclosure panels too. Finish by cutting some more 50mm strips as needed (although they needn't be a set length). Then use a stop block to cut these strips into 60 squares of plywood on the mitre.

Phew! Hopefully all this made sense, that's all the cutting done and dusted.

Here's what turned a 1 hour job into a 6 hour job: using a drill to drill pilot holes, countersink them, and insert screws. If you've got a brad nailer, you'll save so much time here!

Slats are affixed at the top and bottom with two spacers and/or brackets between them.

Start by laying out two vertical slats opposite each other so that they are parallel, 800mm apart on the inside and their longest, pointed side is facing inwards. Then put the first foot rest at a set distance from the bottom; I used a block of wood of length 200mm for this (this will be a guide for all other pieces at the bottom to be consistent). Put glue where the slats and foot rest cross at a right angle, and add some nails. Then add a spacer atop each side of the footrest.

At the top, there's always a bracket with a spacer on top. The bracket should point inwards, with its longest side face up. Its point should be 120mm from the top and at a right angle to the slat it sits on. I used another block of wood to get this spacing consistent.

After you've glued all these pieces together, add the next slat and repeat the process. After the three foot rests at the back, you just use two spacers at the bottom, building your desk up in layers.

Starting from the back allowed me to hold the two sides of the frame together by the foot rests for the duration of the glue up but you could reverse this and start from the front so no nails/screws show (I used glue to fix the front slats on).

The enclosure is just open top box. Feel free to add some real carpentry but I'll keep it simple here. You've got the panels cut, so now you just need to glue and screw them together.

I used 40mm screws and a countersink for this.

All the side panels sit on top of the plywood base panel with lap joints. Add supporting screws through the bottom and glue them so that the front and back panels enclose the two side panels within.

Next, install your box in the frame, I used several short screws straight into the brackets but you could make it detachable.

Now you can add a water proofing layer on the inside, but I kept it really simple and used a plastic tarp and a black tape border. It seems to work well so far.

Finish your frame and box assembly by sanding and painting if you wish. I opted out of using an oil due to the surface area of wood I would have to cover and it still looks nice unfinished.

Cut out an 800mm x 650mm acrylic rectangle. I cut it with a circular saw but be careful, it scratches easily. Glass is a better surface for longevity (and it doesn't attract as much dust). I used 5mm acrylic but it does bow slightly under the weight of my monitor. Use wet and dry paper to smooth the edges.

My terrarium is open because cacti like it quite arid - I hid some venting holes in the side for this reason. It would be possible to make this a closed terrarium but a good seal is necessary and more thought is needed for it to sustain itself and maintain a balance of humidity, soil pH etc.

I chose some small cacti and had just enough cacti compost in a 10L bag to cover the clay pellets I put at the bottom for drainage. I took some small potted cacti and planted them in an arrangement such that a small area was left where my keyboard casts a shadow since any plants under here won't get much light.

Two weeks in and the cacti are looking healthy and unchanged. I did experiment with no vents for the first few days, but regular use of the desk late in the day caused the desk to steam up slightly and this was not desirable. This is another reason to keep it open.

Bear in mind you could add lighting, a hinged top, or use other plants or even an aquarium as your enclosure.

Thanks for reading!