by Joel Dunn
Raised beds are great for deep, friable soil and good drainage, and also provide a nice structure for annual veggie rotations. However, the set-up costs for both the raised edging and imported soil to fill the beds can be a turn-off. This little photo journal illustrates a couple of simple cost savers I used for raised beds installed this year.
For raised edging, I used modular rectangular beds made from re-use of “Klip-Lok” roofing by The Green Community Project at Tuncurry Waste Management Centre. These were very affordable, but obviously it would be cheaper still to DIY with some tin snips and and rivet gun if you were able to scavenge the materials. Other options for re-use bed edges include rings of corrugated iron from old water tanks, and large tractor tyres with the sidewalls removed.
Filling raised beds with imported soil can take a lot of cost and effort. Before these beds were installed, I had been throwing — onto the spots they were to occupy — various bits from around the newly developing garden around them, including dug up tree roots, sticks, grass turfs from dug-up edges, etc. The first two beds were largely filled with prunings (leaves and small branches) from ice cream bean and wattle trees brought over from my more established garden. This provided a mixture of nitrogen-rich leaves for rapid decomposition, and woody material for fungal food and good drainage. This was topped by seaweed scavenged from the beach, grass clippings from neighbours’ lawns, and then finally a much reduced quantity of imported soil.
The photo above shows the first two beds with prunings and seaweed. Note the riser pipes for drip irrigation – if you want drip irrigated raised beds, remember to organise this before installing the edging so that the feeder pipe is buried beneath the edging!
The next two modular beds arrived a couple of months later (there was a gap in “Klip-Lok” supplies being dumped at the tip!), so I had more accumulation of “green waste” from around the garden by the time the edging was installed. The next garden bed over at the front of the house supplied masses of green manure for the next two beds – in the form of a very vigorous Lab Lab bean that I had grown up a Lily Pily tree. This plant grows like a marvel where I live, but unfortunately the beans are not very tasty, hence it is often referred to as “poor man’s bean”, and used for green manure and animal forage.
Lab lab bean can be seen almost smothering the poor Lily Pily – ripe for the picking!
Empty, not yet seated bed edges can be glimpsed in the background.
Beds overflowing with nitrogen-rich Lab Lab foliage
Lab Lab was then chopped up with shears
Beds finished off with a layer of imported soil
I wasn’t sure what to expect from my severe scrimping on soil in these raised beds with seeds planted straight away, but my happy past experience with sheet mulching gave me confidence that the buried materials would compost down below the soil layer and give healthy veggies. As you can see from the nice crop of winter annuals I’m picking at present, I’m very pleased with the result.