I wrote this article 8 years ago and to this day I have found it to be the best and less expensive way to make and grow in a raised garden.
Extract from my original article:
I wanted a raised garden that could be worked without bending down and the cheapest way for that would be to use roofing iron.
Three new sheets of galvanized iron 1.8 metres long and two 100 x 100 fence posts were also purchased the length of which was half the width of the of the sheets of iron.
When you cut the fence post in half and no wastage.
The fence posts are treated with chemicals so to overcome that problem a couple of coats of acrylic paint was applied all over the wood surface after cutting them in half..
The posts are not going to be dug into the ground and the whole raised bed will sit in the ground on concrete.
(Now this is very important that you have a concrete pad to sit the raised garden on.
If not robber roots from plants, shrubs and trees will find your garden and fill it nearly to the top of the soil with feeder roots.
After one season the raised garden will be useless and will grow nothing.)
Construction was simple; lay the two painted fence posts on the ground and place one sheet of iron over the posts to completely cover the two posts.
Check to make sure its square fitting and then drill holes of suitable diameter to take the roofing screws.
On a roof you would fasten the ridge part of the iron sheet so water would flow down the gully part.
For your raised garden the reverse applies. Screw in the roofing screws at both ends of the sheet.
The reason for using screws as opposed to roofing nails is they are easy to unscrew if you want to move the raised garden or extend it.
The same is done on the other long length of iron. You now have two sides so next the ends.
The final sheet of iron is cut in half making it 90cm long, a nice width to work on from one side or both. The posts are going to be inside the bed.
The two ends are screwed to the fence posts. It is best to assemble where its going to sit which ideally one long side should be facing in a northerly direction..
One very important aspect about where you are going to place the garden and that is as far away from trees, shrubs or other plants as possible. (Unless it is on a concrete pad)
If anywhere near say a tree or too close to a drip line, the tree will send out feeder roots to your raised garden and then upwards to take all the goodness out.
The garden becomes a dense mesh of feeder roots over a couple of seasons and nothing will grow in it.
I found this out the hard way as my first raised garden was about a metre away from a fence that had a cocktail kiwi fruit growing on it.
Within two seasons it had become a mass of fibrous roots and resulting in a very big vine on the fence.
If your raised garden is sitting on concrete no problems.
Now you have the raised garden ready to fill.
Any trimmings of trees and shrubs goes in onto the pad along with any organic material which can be grass clippings (not sprayed with herbicide for over 18 months) sawdust, newspaper, old spent compost, old potting mixes and even some top soil (which is likely to have weed seeds in it.)
Filling the raised garden to about half the depth. You can even trample it down and add more to about half-full.
Over this you put several layers of newspaper. Cover this with purchased compost that is NOT made from green waste.
Daltons & Oderings Composts are two safe ones along with straight mushroom compost.
The fill will take it to about 35cm from the top of the raised garden.
Now you spread some goodies such as Blood & Bone, sheep manure pellets, Neem Tree Granules, Wallys Unlocking your soil, Ocean Solids, chicken manure and the cover these with another layer of purchased compost about 5cm deep.
This should then be about 20 to 30 cm from the top of the raised garden and ready for you to sow seeds or plant seedlings.
After planting you can stretch some netting or crop cover across the bed and holding secure with a nail in each corner post.
This will stop birds and cats from getting in and destroying your plantings and if crop cover is used it will stop most insect pests as well including butterflies.
Having one long side facing north will heat up the contents through the iron; warming nicely the mix.
The gap between the mix and the top creates a wind break and so you have your own special micro-climate and plants will grow twice as fast compared to if they were in open ground.
When a crop is harvested just place more goodies into the bed and cover with more compost.
You will get years of pleasure and nutrition dense vegetables for your health.
You can easily extend the raised garden with two more 1.8 sheets and one more post cut in half.
Unscrew one end that you want to extend, removing the end section. Unscrew the sides at that end so your new sheets will overlap onto the existing and be screwed on together.
Posts at other end will take the end half sheet and now you have 3.6 metres of raised garden.
Fill this as previously. You may need to place a brace across the middle posts to prevent it bowing outwards.
Happy Raised Gardening.
Mentioned previously in several articles about a pending food shortage I see this week that The UN has announced a catastrophic world-wide food shortage pending.
I also see that, ‘Farmers in England have been given taxpayers’ cash to rewild their land, under plans for large-scale nature recovery projects announced by the government.
These will lead to vast tracts of land being newly managed to conserve species, provide habitats for wildlife and restore health to rivers and streams (6/01/2022).
The ambition at Rewilding Britain is to see nature recovering across 30% of Britain’s land area by 2030.
That’s equivalent to approximately 7 million hectares.
In NZ we also see Government encouraging tree planting and conservation programs to reduce the land that is farmed.
There are moves to apparently introduce Frankenfood: (Perjorative term for genetically modified food whether it be derived from genetically engineered plants or animals).
All sounds like conspiracy stuff but if the arable food growing land is reduced and major food suppliers like Russia and Ukraine no longer exporting food stuffs from crops there is a problem.
Best you grow as much as you can and also stock up with essentials like flour, rice, pasta and tins of food.
Remember money is only as good as what it can buy and if there is nothing available to purchase money is useless.
Food then becomes very valuable along with fuels.
Also other bits if you email me.