Low-Carbon Landscaping

Over the last year, we Heronswood gardeners turned landscapers; fixing, realigning and redesigning paths, walls, ponds and beds.

These works were undertaken with the motto of the house’s architect, Edward La Trobe Bateman, in mind – “There’s no excuse for ugliness, as beauty properly understood was cheap” or, as we put it, “Diggers can’t be choosers”

What became clear was the landscape we produced as gardeners was quite different from the work produced by the usual landscaper of retaining walls, decks and pergolas, or the high design and high input gardens you might see on TV.

Our gardeners’ landscape maximised plants and our wonky walls and raked paths seemed to grow out of the garden itself. 

Landfill, then fill the land

The contrast was brought home to me when I was working on another, conventional garden rebuild. Skip after skip was loaded with moss rocks, paving stones, plant material and topsoil, then driven away to landfill. The site was scraped clean, then new manufactured materials were brought in, I noted from the packaging some from as far as China. The hardscaping began, the garden beds shrank, gravel paths were replaced with exposed aggregate concrete, six-inch pots of grasses replaced mature trees and shrubs.

At the same time the Glasgow summit was happening, with its goal building a net zero carbon-emitting society by 2050. What hope have we, if even our gardening contributes to, rather than mitigates, our emissions? What does low-carbon landscaping look like? My research revealed a few common principles of low-carbon landscaping that minimise emissions and lead to landscapes that absorb carbon from the atmosphere. These were: use local materials, maximise vegetation cover and reuse, recycle and retain material on site. At Heronswood I was delighted to discover our love of plants and thrifty reuse had made us incidentally ethical in terms of carbon use.

Use local materials

Making it local is not just good in terms of energy reduction, it also makes for a garden that respects its spirit of place. For us in Dromana, the product we brought in the most was local granite dust for the paths and mulching of beds in the gravel garden. Stone dust or crusher dust is itself a waste or by-product from the crushing of other quarried products, in our case produced and transported less than 5km. It compacts well, but lets water infiltrate, rather than run off.

The other advantage is it is very DIY friendly and easily moved and reused to make way for more plants. There would be similar types of crusher dust products available near you.

Work with existing plantings

Maintaining vegetation cover is important to us. Many bushes and trees, like people, can look tired as they age. Unlike people, they can be restored through regenerative pruning. To some it appeared as if we had removed much of the garden, but we had just hard pruned many of our overgrown hedges. Other plants we shifted. Maintaining and working with as much of the mature planting as possible is vital to keeping both the essence and carbon of a garden, which cannot be replaced with tiny buy-ins. Clean slate gardening is easy – what takes skill and time is working with what you have. Some plants may not be your favourites, but with effort you can transform them into something you love.

Reinventing existing materials

The greatest environmental positive of our landscaping was reusing and recycling the materials we had at hand, not throwing out or buying in. Seeing the potential to reinvent existing materials is key to low-carbon landscaping.

We had a series of rather ugly, unsympathetic stone walls that were built in the sixties. What made them undesirable was not what they were, but how they had been made and used. After dismantling the walls, we instantly had a huge supply of granite to repurpose in a way more sympathetic to the Victorian house. We dry stacked this material to make low retaining walls, no need for carbon-heavy concrete.

All our walling and levels were created to be DIY friendly, with nothing over a metre. Where a planted slope would work, we chose that over a terraced retaining wall. All the concrete we pulled up we used as back fill, incorporated into the walls or stored for future use as crazy paving. Aged concrete has a beautiful patina that is of the place, it certainly is not a second-rate substitute. If you do not have access to these materials on site, local classifieds are full of these materials, and often they are happy for you to ‘pick up only’.

With climate change comes storms. Many large cypress and oak trees lost limbs, but all this became material for our landscaping.

One of the most noticeable features of our landscape are our log walls constructed by Rupert, our apprentice. They were inspired by Hügelkultur, the art of creating garden beds of soil over logs and woody material. This is an efficient way of sequestering carbon into the soil profile. They look great freshly laid, with the intention they will slowly break down, melding with the new planting to stabilise the bank. They are a feature that would be costly to buy in and construct, but to us, apart from our labour, they were free. The smaller branches we chip and use for mulch. All our other mulching is either our own compost, wood chips from our arborist or broken slate from our roof.

I hope this article empowers you to use some of these ideas in your own landscaping adventures and to become part of the climate solution, not the problem. We found it a creative process – certainly no easier than conventional landscaping, but more fun!