Soils aint soils

Now that the new fence is up, I’m starting to think about how we will plant along it. I want a little mini grove of fruit trees – I’m hoping for two espalier apples, an apricot, a nectarine and a plum. All either dwarf or pruned to stay reasonably small. I’d like a very small, skinny food forest – underplanted with nasturtiums, comfrey, alpine strawberries and horseradish.

The only problem is the ground along the fence is rubbish. I can’t even call it soil. It is heavily impacted clay (had a concrete slab and shed resting on it for 40-odd years), with bricks and bits of concrete smushed in there. And the clay isĀ clay. We could ditch the music studio and start a pottery workshop. But clay can be broken, as long as it’s the right clay. Sodic clay can be broken with gypsum, but non-sodic clay can’t. Time for some kitchen science!


I got a lump of clay from the backyard and popped it in a glass of water. Now we watch for dispersion. If the soil just sat there, or fell apart, then it would be a stable aggregate that wouldn’t respond to gypsum. But that big cloudy halo means that it’s unstable – and gypsum can help break it up.

So I’m off to Bunnings to get some liquid claybreaker. After the builders have cleared all their stuff from the area, I’ll pop in some sleepers (or maybe use the bricks I unearthed) to raise the soil surface, and then dump a trailerload of compost in there when we fill the veggie beds. Then maybe a summer green manure before the trees go in.