Raised Garden Beds in the Bush – Growing Your Own Food in Poor Soil Conditions
“We acknowledge and pay respects to the Dhurga people of the Yuin Nation, the traditional custodians of the Country where we live.”
When we moved to our bush property two years ago self-sufficiency was high on the agenda. We wanted to produce our own electricity, collect rainwater and we certainly wanted to grow some or if possible most of our own food. This included an abundance of fresh fruit and vegetables and we both envisaged a fairly large space for vegetables, berries and flowers intermingled in a lush, productive garden. But for the time being, while we were building a house and joinery workshop, we had to be content with a single ‘temporary’ garden bed so we could start growing some fresh greens. The bed was constructed with two curved, 5m long zincalume sheets that were left over from our roof installation. We screwed the two sheets together at the ends to form an elliptical shaped bed 0.9m high. Working the bed at this height – sowing, planting, mulching, harvesting and pest control – has been extremely convenient and the ‘temporary’ bed turned out to be a great success and supplied us with an abundance of food.
The following spring we added a second, rectangular bed made of other scavenged sheets to accommodate some tomato and zucchini plants. Once you have started to grow your own food you never really grow enough or have enough space. There is always another variety that should be added to the mix. The second raised bed planted with zucchini and tomato plants is pictured in the image at the beginning of the article. The long sheets were not supported and the beds started to budge when they were filled with compost.
Once the building of the house was more or less – sometimes more and sometimes less – under control we sat down to figure out the location and design of the ‘proper’ meaning more permanent garden. Our piece of land presents some challenges; there is no flat ground near the house, in fact there is hardly any flat ground on the property, wildlife roams the land and I won’t go into details as I’ve had a whinge about it in our orchard update (link to article https://permaculturenews.org/2017/02/16/second-steps-food-forest-southern-tablelands-update-2011/), and the soil is rather poor for vegetable growing consisting of loamy clay and shale rocks. When we discussed our dilemma with a friend, she promptly replied “You have basically no top soil, you might as well grow your food above the ground”. So after much discussion and advice from seasoned gardener friends we decided to design the vegetable garden as a series of raised garden beds. The main advantages for us were: no effort and time spent on improving/’de-rocking’ the soil on the ground, which would have meant tons and tons of organic matter worked into the soil and hours spent collecting rocks; no money and time spent on building a ‘bullet-proof’ enclosure to keep the roos, wallabies, wombats and rabbits out; easy access and no crouching or crawling around on hands and knees to work the beds. On the other hand, the disadvantages were: time and money spent on building of the beds including levelling of the ground; larger area required due to allocation of paths; potentially increased evaporation and soil temperature in raised beds compared to ground level; and saying good bye to the dream of a flourishing, productive garden and hello to rows of giant planter boxes instead.
We decided the beds should go next to the solar panels close to the house. As we liked the height of the temporary beds and we wanted to optimise the space available for growing, we decided to build the new, raised beds based on our own design using metal sheeting again. Timber would have been too costly to build 0.9m high beds and we were offered a stack of second-hand roof sheeting for $250, which allowed us make twelve 3m x 1m x 0.9m beds in total.
We wanted the beds to be more solid and look more attractive. To have a nicer finish, we screwed the sheets together at the four corners using 2mm thick galvanised metal angles 40mm wide. Depending on the profile of the sheet metal used, raised beds up to 1m high can lose their shape and bulge once they are filled with soil. We therefore also used 10mm galvanised metal rods to connect and stabilise the long sides of the beds internally. The rods were fixed to the sheeting with bolds and washers on either side, which held a 4mm thick metal flat bar in place. Instead of the flat bar one could also use, for example, star pickets to brace the walls. In total, we used 4 rods and flat bars for each bed. We had to purchase the rods, angles and flat bars for a total of $750, but one can certainly improvise in regards to the metal used and build the beds cheaper.
We did not want to buy soil to fill the beds and we had previously made large quantities of compost so we could half-fill the beds. The bottom half of the beds was filled with timber logs that we had cut from fallen trees. The logs provide drainage, decompose slowly, and provide nutrients for the plants above. Rocks, sand or any other material, that is available for free and provides drainage, would also be fine. As our compost is sawdust heavy and not fully composted yet, we added horse manure for additional nutrients, some commercial compost from a facility nearby for additional microbes and some sieved soil and dolomite lime for minerals. We had noticed that the compost-based, temporary beds had a calcium deficiency because some of the tomatoes had blossom end rot. Building the beds wasn’t as time-consuming as half-filling them with the logs, which we had to do by hand. The filling of the beds afterwards with compost was done with a tractor and therefore relatively quick and easy.
Then it was planting time! We quickly filled the beds with brassicas, spinach, lettuces, beetroot, carrots and parsnips. As I mentioned before – there is never enough space for everything. But we managed to plant a lot and are eagerly waiting to harvest our first crops. This morning, like most mornings for the last three weeks, I wandered to our new, raised garden beds to admire the beautifully growing winter vegetables that we planted 25 days ago. When I looked at the little plants I noticed that some of the brassicas had holy leaves. Closer inspection revealed that cabbage white butterfly caterpillars were the culprits, hungrily consuming the juicy leaves. After I had removed the caterpillars and tiny eggs I realised how easy it had been to spot them thanks to the very convenient height of the beds. Raised garden beds can never replace a beautiful conventional garden, but I’m convinced we will have an abundance of fresh food growing in our raised beds, and the addition of flowers will continue to bring insects to our garden, too.
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