When I made my first raised beds on my allotment I used cheap softwood, stained and nailed. They rotted in three years and even after the first year the pressure of the soil made the nails fall out. You live and learn I guess.
So this time round I went for quality and build strength. My budget I worked out was about £500. This time I spent time thinking about the project to make them as useable as possible.
The project is still carrying on - you can visit my blog on www.waark.com to see where we're at and any other innovations we're developing.
Step 1: Clearing the Space
We bought a roll of weed suppressant membrane which was about 3 meters wide. Overlapped, it's a pretty impenetrable barrier.
At the end of the allotment area we'd got some IBCs which we're using for watering the plot. 3,000ltrs worth. They used to contain fruit juice from a local supplier and are on a crushed stone base on slabs.
I put down a sprinkling of weed killer as well - this was to kill all the other perennial weeds that can punch through concrete if not treated!
Step 2: Materials
They're actually the same size as scaffold planks - 13.1ft long and 226mm high (to mix a few measurements)
Step 3: Making the Beds
We did have to work round one cherry plum tree.
You need to make sure the space between beds will accommodate the longest legged person kneeling and/or any wheel barrow or lawn mower if you're not paving.
To build the beds I used a self taping coach screw which was M10 in size and added M10 large washers to spread the loading. 2"x2" was used for the down posts which I manually sawed at 45' angle. The first box we attached all of the down posts and hammered them in. It took an awful lot of effort to level it and get in the ground.
On the rest, we used flat posts on the corners and put the box in position. I then hammered in the supporting posts at 1/3 intervals along the sides and then screwed them in. This was much easier and quicker and made leveling the boxes much easier. Most were leveled by eye...
Step 4: And Multiply by How Many You Need
Step 5: Lining the Boxes
A stapler was used to pin the material to the boxes.
Step 6: Filing
It was not fun. We started about 8am and finished about 8pm. We had blisters and soil everywhere.
Step 7: Grow!
Over the past few months they've been used as giant litter trays and been covered in several inches of snow, but they've held up well.
About three weeks ago I planted out sets of heritage seeds - old style seeds which you can't buy from shops but specialist seed suppliers. I've got white beetroot, rare lettuce mixes and strange sounding salad leaves. All are doing well!
My next project will to be to setup the greenhouse and install a drip irrigation system from my IBCs!