The other week at my ever-challenging and interesting plant design course at Capel Manor, we got to talking about environmentally-friendly gardening.

Now, I’ll nail my colours to the mast here and say I’m not entirely organic – I’ve been known to spray bindweed with glyphosate when nobody’s looking, and my most heinous crime is to Pathclear my patio and driveway every year which I will no doubt have to account for in the afterlife. However – five minutes of talking to my very knowledgeable classmates has made me realise there’s rather more to it than that.

We were talking about gravel. I’ve got loads of the stuff here – on my driveway, on the patio, and under my cold frame. It’s cheap and easy as pie to use, I buy big jiffy bags of the stuff every few years or so to top things up, and until now I’d thought that was a relatively neutral material, insofar as I’d thought about it at all: the RHS promotes it as a good alternative in its “don’t pave your front driveways” campaign, after all, doesn’t it?

Not so. Marine-dredged gravel is the worst of all: “harvested” by something akin to Spanish trawlers only much, much more devastating. They suck everything up off the seabed to a depth of a couple of metres, killing all marine life that happens to be in their way, then they clean, grade and sort the gravel and spit back into the sea what isn’t needed. Incidentally smothering all marine life that happens to have wandered into the area in the meantime.

So – you avoid that like the plague, and source it as land-dredged gravel, right? Well – if you can get companies to specify where they get their gravel from – this is certainly better. But the amount of fuel it takes to suck the stuff out of the ground, sort, grade and then transport it where it’s needed requires a few aircraft-longhaul equivalents of carbon a throw.

This was all getting me in a real gloom. I was already having a conscience about using paving to hard-landscape the area around my shed and greenhouse (the garden makeover is proceeding apace, of which more later). It’s not just the (itself not very eco-friendly) paving: it’s also the sand and the cement-based hardcore I don’t like having to use. Now it turns out the so-called ‘better’ options like gravel actually aren’t.

The ‘green’ alternatives to gravel – bark chips, recycled tyres or bright blue recycled glass bits – are either too hippy or too horrible to contemplate. Or they wouldn’t last five minutes. And then I discovered the wonderful world of recycled aggregates.

This is basically some of our rubbish that would have gone into landfill but is instead crushed down and sold back to us as gravel-like surfaces for pathways and hard standing. Surprisingly, for what might seem like an obvious idea, it seems to be a bit new, so there aren’t that many people doing it yet. Long Rake Spar, in the Peak District, does a gravel made of crushed building materials that looks pretty good (and very like regular gravel), but the one I really like the sound of is sold as Traxmax. It’s ceramics, either tiles or bathroom suites (I wonder if it’s sometimes avocado-coloured?) taken out of the local tip, hopefully cleaned up a bit, smashed up into little bits and delivered in a big bag. The best thing about it is that because the original ceramic was made of clay, once it’s broken up it becomes a little sticky again – so when you put it down on your path and it rains, it bonds to itself and becomes a solid surface.

You get it from this company – the only supplier I could find – and it’s not even very expensive. There may be a catch: but I’m going to give it a go and I’ll let you know what it’s like. And anyway, I kind of like the idea of walking over second-hand loos on my way down the garden.