Following on from my previous post, this one is about constructing the actual frames and filling them with soil…
With the post holes bored, I started on the frame construction. I used 10 cm ‘bugle batten screws’ to join everything together,, which are self drilling so no need to pre-drill… not in pine anyway. Which was just as well as I used over 100 of them in the tree bed alone! Here are a couple of pictures of the frame being constructed:
The concreting of the posts was back breaking work. I used ‘post hole mix’ which comes with aggregate (gravel) already mixed through, and just needs water to be added. Apparently the way you see them do it on home improvement shows on TV with quick-set cement, i.e. chucking a bag of cement in the hole then spraying a hose down it, doesn’t give the strongest concrete. The drier the mix, the stronger the concrete, and you can’t really control the amount of water if you do it that way. Also, with the post hole mix, as I discovered it’s pretty hard to mix in a bin, never mind in a hole with a post in it.
No point in going to all this effort for crappy weak concrete I thought, but that meant I had to mix 22 x 20 Kg bags of concrete by hand. One by one. With a shovel. In a plastic bin. It was 440 Kg in total: 3 bags per post, plus one extra for a hole that was a bit wider than planned. For my first hole I was a bit gung ho, and tipped all 3 bags into the bin at once and then added the water. Mixing that was seriously hard going, so I learned my lesson and did one bag at a time after that! By the end of it every muscle in my body was aching but I had a nice sense of achievement.
Oh, I have a tendency to over engineer things, and I had a niggling doubt that with posts as tall as mine, even 60cm plus the depth of the soil in the bed might not be enough to hold them firm, so I made my metal bracing bars (see previous post) dual-purpose, by screwing them to the posts as well as the sides of the bed frame. Hopefully between that and the concrete, my posts aren’t going anywhere soon and will support the bountiful crops of fruit in years to come!
Next up were the veggie beds: I built three of them, each one a sleeper long and half a sleeper wide ( 2.4 m x 1.2m), in front of the tree bed. While constructing the tree bed and cutting long thin triangles of wood to fill the gaps, I was reminded how much of a pain it is to cut wood along the grain like that, and also when you cut treated pine, you need to re-treat all of the cut surfaces with a horrible thick green paste. Not very chemical free!
So I decided to take a slightly different approach to the veggie beds: the way I made them level was to dig them into the ground instead. In terms of effort, it was probably harder work, because digging through the well established thick buffalo grass into the heavy clay soil was pretty tough going. Still, it was nice not to have to slather the horrible thick timber treatment everywhere on these ones.
I dug out the grass in the uphill end of the beds, just to create a bit more depth for the soil I was going to add, but I left the grass at the downhill ends. Before filling them with soil, I laid down sheets of brown corrugated cardboard and gave it a good soaking. This will suppress the grass and break down over time, adding organic matter to the soil.
I then spent two weekends carting two separate deliveries of ‘veggie mix’ from a landscape supply place, from the front of our drive uphill to the back of our garden. One painful wheelbarrow at a time. In total, I shifted about 6 cubic metres, which is about 7 tonnes apparently!
This is what 4 cubic metres of soil looks like:
And here are the finished, filled beds:
Next: installing wires for the trees to be trained on, and of course planting the beds! But you’ll be glad to know that’s for another post…