Part 3 of our 3-part series “How Can We Landscape More Sustainably?”

  • organic and inorganic mulches
  • growing fruits and vegetables in public places

In the first part of this series, we talked about how we can conserve water during the dry months. Part two looked at how we can save water in the rainy season and mitigate the risk of flooding. Mulches also play their part in water retention, but they are also a key contributor to sustainable landscaping. Let’s take a closer look.


Organic mulches

In landscape design, the most commonly-used organic mulches include bark or wood chippings, chopped straw and fallen leaves. Other examples of organic mulch are fresh or old hay, wood shavings, fresh-cut forage and other crop residues.

The advantages of organic mulches are that they are an excellent way of repurposing natural by-products, often created in or near the garden. Grass cuttings, shredded foliage and chipped wood can be utilised as a free source of mulch.

They also often include nutrients which will enrich the soil and may provide habitats for beneficial worms, bacteria and fungi. Ironically, the downside of organic mulches is that they may harbour bacteria, fungi and insects that are damaging to plants.


Inorganic mulches

An inorganic mulch is made from anything that hasn’t previously lived. Most common examples are rubber chips, non-woven geotextiles, gravel, stones and rocks.

While inorganic mulches are unable to enrich the soil with nutrients, they can perform many of the duties carried out by organic mulches and are less likely to contain harmful organisms. While they are largely non-degradable (often a minus point when we’re talking about sustainability) this also plays in their favour: they are slower to break down, meaning they will perform for longer and require replacement less frequently.

It’s a good idea to lay a geotextile underneath inorganic mulches such as rubber chips and gravel, as this allows easy removal of the mulch and prevents it from being absorbed into the soil.


Keeping mulches in their place

Mulches should be treated like a loose aggregate to prevent them from spreading to adjacent areas where they will be unsightly and unwelcome. Once again, metal landscape edging can play an important role here, particularly if the mulch level is higher than that of surrounding lawns or paths.


Fruit and vegetables in the urban landscape

One important feature of sustainability is reducing the distance that fresh food has to travel to our plates. And while the average town garden or city roof terrace is too small to support self-sufficiency, it’s remarkable how much can be grown in a relatively small space.

Nor does the garden need to resemble a scene from ‘The Good Life’. Fruit trees and bushes can be trained into espaliers against walls or screens, while planting flowers and vegetables together is beneficial to both, according to gardening experts. The result can be a delightful (and fruitful) combination of textures and colours that changes with the seasons.

Growing vegetables on a roof garden or terrace might be regarded as a bit of a challenge, but is quite viable and all that extra sunlight will be invaluable for plants that like their vitamin D. You will need to ensure that plants – particularly those growing up canes or on trellises – are sufficiently protected from the higher winds they are likely to experience at this altitude and you will need a good depth of earth for roots to take hold and flourish.

RoofEdge, the innovative steel edge restraint we mentioned in the previous post, is manufactured in a range of edge depths up to 250 mm which – provided you aren’t planning on growing potatoes – will be more than sufficient for most plants. If you are contemplating fruit bushes or small trees on the roof, however, you probably need to be looking at planters as they will give far greater root depth and will retain more water.


This is the third in a three-part series on sustainable landscape design. Other posts in the series are:

We hope you have found this information helpful and interesting, and if you would like to find out more about aluminium and steel landscape edging, call the friendly team of experts at Kinley on 01580 830688 or email