BANK ON IT GARDENING
Mass planting can look fantastic on your garden slope Leigh Bramwell
THINGS CHANGE FREQUENTLY at our place. Yesterday we were talking about how to deal with a bank area we refer to as the Septic Garden. The name refers to the fact that the lid of the septic tank is at the bottom of the bank. This less-than-charming title may be the reason that the area has remained untouched for months, if not years.
About a decade ago there were three Monkey Apple trees planted there but they grew taller than The Landscaper could stand and shaded the car park from the sun. They came out and were replaced by what should probably be called a trash garden – an area you fill up with any old thing that has roots. Then a couple of months ago, in a rush of blood to the head, The Landscaper emptied the trash, so to speak, leaving a bare bank. Oh dear.
Banks have never been my forte. I like flat spaces — possibly as a consequence of growing up in a hill suburb of Dunedin accessed by a set of 284 concrete steps going from the bottom of the hill to the top. Yes, there was also a road, but as a schoolgirl I walked up and down those steps at least four times a day and I could still tell you how many steps were in each flight.
So the Septic Garden has not been on my priority list until recently, when I abandoned an idea I’d had to put the whole thing into ground covers with a few rocks, and decided to pack plant it with shrubs. Nice shrubs, not trash.
I did some homework before racing out to waste a whole heap of money on plants unsuitable for banks. My first lesson was on shallow erosion-prone soils. On these areas water runs downhill before it gets the chance to soak in, and, companionably, it takes the soil along for the ride.
Lawn or pasture helps to bind erosion-prone soil, but who wants a wee paddock right next to their entranceway? Anyway, Auntie Google said low-maintenance shrubs are a more sustainable option.
Mass planting can look fantastic on a slope. Take it from me – I’ve looked at a zillion photos on Pinterest and Houzz and it’s definitely the go. Choose a selection of different plants so if you make some poor choices at least they won’t all kick the bucket at once. The toughies will survive.
I’ve read heaps of advice about planting a native-only garden but I’m going to ignore it (possibly at my peril) because I have certain plants I really love. So I’m choosing the favourites which are already doing well in our other garden areas, as well as a few new ones just to keep me on my toes.
Most of Auntie Google’s friends say to start planting in swathes at the top of the slope and move downhill as each swath is completed across the slope. This sounds very sensible to me and will keep me focused on the job at hand.
There’s a trick to planting trees and shrubs on a slope and luckily it’s an easy one. Make a flat area (like a mini terrace) before digging your hole, either by cutting into the slope or building out using timber to hold the soil in. This will discourage the water from running down the slope before any of it soaks in.
Dig the hole three times as wide as the plant’s root ball and position the shrub so the roots and trunk are vertical. The root ball should be flush with the soil on the downhill side. Remove soil on the uphill side so it is doesn’t pile up around the trunk.
Unless you want to spend much of the summer hosing your bank and watching the water run down to the bottom, consider drip irrigation — the little drops of water don’t run off.
The Landscaper, off to the South Island for a few days, has left me with instructions to have a design and planting plan drawn up by the time he gets back.
And I was going to, honestly, but it suddenly occurred to me when I was squeezing the car into the small parking space abutting the Septic Garden that a minor change of design could kill two birds with one stone.
Imagine if a friend with a wee digger were to level off the top part of the slope and The Landscaper were to build a small retaining wall across the breadth of it. We’d reduce the size of the slope by a third, and increase the size of the carpark area by a considerable amount.