With its unique natural beauty, stone is a favourite of gardeners everywhere. Whether used as steps, paving, retaining walls or buildings, this most original and durable of landscaping materials settles into its surroundings, ageing gracefully with a natural patina that appeals to our primitive aesthetic instincts in the same way as do forests and oceans, writes Helen McKerral
When we moved into our Crafers home (in the Adelaide Hills) three decades ago, one of our first building projects was a slipform stone front wall, using rocks we collected from a nearby quarry, so cheap as to be nearly free. We read up on the technique and, although the wall is now showing a few cracks because we didn’t bother with capping stones, it should nevertheless last long enough to see us out.
Next, I built low curving retaining walls from book leaf slate and, rather to my surprise, they have not budged after more than two decades despite my less-than-perfect building skills (hint: batter is your friend! This is the receding slope with which it leans back into the area you’re retaining).
Today, that slate retails at about $400/tonne and, even for a permanent walling and surfacing solution, that’s a decent hit to anyone’s hip pocket. Of course, book leaf slate is a dream to work with, easy and fast to lay due to its regular sizing and symmetry, which might improve its value for money if you intend to pay someone else by the hour to build your wall
I’d also inherited a quantity of grey paving slate from my grandparents. This was enough to crazy pave our outdoor entertaining area, with generous gaps left for prostrate thyme. This looked great until the Chinese elm completely shaded the area. The thyme became sparse, weeds infiltrated, nothing else I tried thrived, so it was time to rethink the surfacing.
I decided to buy additional slate to re-pave with stones abutting but, at the time, cost was prohibitive. Could I perhaps save money by going direct to the quarry? Indeed, yes, and they had a discard pile I could sort through to handpick the stone I wanted. The pile was enormous, several times the size of my house, and there were pieces of every shape and size, many too large for me to lift. I selected also several rectangular slabs, each with at least one long intact side, that would make perfect steps.
The trailer load of Mintaro slate cost about $60 – now it’s about double that, still a very good price. Unsurprisingly, the pile is a lot smaller nowadays!
When it’s gathered locally, as when I built retaining walls from rock excavated from the same spot, stone blends seamlessly with the landscape
So, after my initial horror at the number of rocks in my new little plot, I soon appreciated them for what they were – a wonderful, free resource that required no transportation, and which would have cost many thousands of dollars had I to buy them. Not only that, but no need to lug each rock sixty metres from the street frontage!
When I ran out of rocks, a neighbour let me collect them from her block in exchange for eggs and produce. Unlike moss rocks, which comprise important habitat best left in situ, most of my neighbour’s had been unearthed from the original house excavation.
You may not have rocks like this to collect, but keep your eyes open for other options. Look for building or demolition sites nearby: most kinds of stone are uneconomical for recyclers to transport and you may be welcome to take them free. Catherine Stewart created cheap walling by recycling concrete – a beautiful and environmentally friendly option which has a very similar effect to stone when recycled.
Many people buy too much rock for projects and are happy for you to come and take the excess away – check adverts on Gumtree. Just remember to be selective – a mishmash of numerous different stones will look terrible in the hands of anyone but an artistic expert so, if you need multiple loads, be patient and stick to the kind that is most readily available in your local area. In my experience, the bigger the rocks, the better, as long as you can handle them (ahem, see below!). They are much faster and easier to lay, and form a more solid and pleasing appearance.
My fourth and finest windfall was from a nearby suburb. A friend’s neighbour was installing a huge underground water tank. The excavation unearthed vast quantities of beautiful flat slabs of stone. My friend took many tonnes for paths and retaining walls, but much more remained. All the rock was going to be bulldozed over the edge of the hill and buried, so Geoff and I were welcome to collect as much as we wanted. After half a dozen muddy and laborious loads over the course of a fortnight
I thanked the owner profusely and raved about how beautiful the material was, how versatile, how easy it was to work with, and how I was going to use it. Perhaps I was a little too enthusiastic because, a few days later, she decided to keep the rest after all, for use on her own property! Oh well, she had been very generous, we’d received a huge quantity of beautiful free stone and we thanked her with a very nice gift basket of most excellent wines and cheeses, supplemented with fresh home-grown produce, jams and sauces and an offer of a free garden consultation!
So what was all this stone for? Well, when we first built, we scored several trailer loads of old red bricks, which we laboriously cleaned by hand, and which surfaced the driveway and various paths. Alas, although these are fine in most of dry South Australia, our first long, damp Adelaide Hills winter caused these bricks to become very slippery, especially wherever the paving wasn’t completely level
Elsewhere, a flight of steps made from concrete pavers was butt ugly, and I’d wanted to replace it for years
Yet another path started off as slate but then strangely morphed into brick, which turned out to be one of those subtle but ongoing annoyances that we all have somewhere in our gardens. And alas, the hand-picked slate windfall turned out not to be the same as that of my grandparents’ naturally split stone. Instead, like the bricks, the sawn Mintaro slate became dangerously slippery, and got me at least twice every winter.
So we decided to lay a path of the new, non-slippery stone through the crazy paving and extend it to replace the Mintaro slate/brick path immediately beyond it to unify the whole area
The Mintaro slate I moved right down the back to a small seating area that is only used in summer and which receives little traffic.
This paving took a long time because the stones were every possible thickness, from 300 mm to 5 mm. Alas, only after I’d laid half of it did I discover the magic of a bolster chisel – a tool I didn’t up until then know existed! – so was able to split many of the stones, almost doubling the useable surface area of the remaining material.
Most recently, I’ve used most of the last stone for a rustic (read: functional but rough and unprofessional!) 30 metre path through the native section of the ‘new’ area
All that’s left are several chunky pieces – ideal for more steps – and a few too-large three-person rocks that Geoff and I were able tip into the ute from a ledge, and tip out at the front of our house, but which we can’t move into the garden without the help of several strong friends!
Nevertheless, these huge pieces will make beautiful seating and won’t be wasted. You may not be able to afford to buy stone, but the foraged alternative is just as beautiful, well worth patient hunting!
About Helen McKerral
Horticultural journalist, photographer, contributor to many garden magazines, and author of ‘Gardening on a Shoestring’. Adelaide Hills, South Australia
This article was originally published on Garden Drum and is republished here under Creative Commons.