Last weekend I spent two days building a rolling planter box with my Dad.
The “design phase” of the project was pretty casual and was of little consequence, as we changed my design significantly throughout the build. I had a vague idea to build a table-height planter on stilts with wheels, so that I could put other plants underneath to save space and be able to easily re-use water that ran through the bed. My imagined planter box was also a lot smaller, lighter and more compact than the finished product. The sketches below show the entire extent of the design-phase. The design changed substantially while we were at Bunnings getting the supplies, the dimensions of the available wood meant changes to the dimensions of the box, and the larger box necessitated the placement of the box closer to the ground. It ended up being about 1200mm long and 850mm wide at its widest point, with the actual bed ending up 900mm long, 550mm wide and 300mm deep.
The design was based two different concepts – the first was Stephanie Alexander’s description of her rolling vegetable boxes in The Kitchen Garden Companion – she has a courtyard similar to mine, and she rolls the boxes out of the way when she needs the space back for entertaining. The second was the “No-dig apple crate” garden from The Little Veggie Patch Co’s book How to grow food in small spaces.
Stephanie Alexander describes basically how she had the boxes made, and the no-dig apple crate project gave me a few ideas about how to layer organic material in the box – I ended up using their layering technique and adjusting the layer depths to fit the depth of my own planter box.
I used treated pine because it will last the longest outdoors and it was far cheaper than the other wood varieties available. This is also my first attempt at something like this and I didn’t want to spend a fortune on it. I have read that you shouldn’t have treated pine in contact with soil you are growing food in, so I lined the box with a waterproof liner. Limiting the amount of water that sits against wood on the inside will also help to prolong the life of the planter. The plastic is nailed over the edge of the walls to prevent water trickling down against the wood from the top. The bottom is made from a piece of plastic lattice cut to size, pinned in place, and reinforced with a cross beam. Many planters like this that I have seen online have particleboard bottoms with holes for drainage – but that didn’t make a lot of sense to me. I finished by poking lots of holes into the lining for drainage with a drill.
The layering technique suggested by Fabian and Mat from The Little Veggie Patch Co is alternating layers of slow release organic fertiliser, mushroom compost, lucern hay or pea straw, and worm castings. It’s a “no-dig” technique, which means layering organic matter so that feeds your plants as it decomposes (rather than tilling the soil) – you just top it up at the end of the growing season with another layer to build it up after a season of decomposing. After filling the bed, I let it sit a few days to settle in.
Its just Autumn here now, so I’ve decided to plant some snow peas and some beetroots. I have constructed a bamboo teepee for the snow peas to climb on. Once the seedlings sprout, I will mulch the bed and think about a possum net.
The whole project took two days and cost me just shy of $200. I definitely think it could be done more cheaply with better planning. It could also be done more quickly – my Dad and I definitely took it at a leisurely pace, plus we spent a lot of time rejigging the plan as we discovered new problems and opportunities for improvement.
I am treating this all as a bit of an experiment, I’ll let you know how it goes!