Call of the wild: the path to a nature-friendly garden

From Versailles formality to Derek Jarman’s romantic, rebellious yard in southern England, gardens involve persuading and controlling nature. And as our understanding about climate change grows and we come to accept that insect life may be more important than weed-free borders, and carbon sequestration a higher priority for soil than a rose garden, our changing ways of controlling and persuading our gardens are affecting their appearance. I’m not talking about the professional gardens run by hot-and-cold running gardeners, so much — this all starts in our own backyards. 

There have been moments on my journey to coax various gardens into bio-rich climate-change resilience that I have been tempted to throw in the trowel — or at least reach for chemicals. I have persevered, mostly without chemicals, and the result is a style that can loosely be described as “shaggy”. 

Three years into renovating our current Oxford garden and some visitors assume, wrongly, that I have a devil-may-care approach. Our alleged lawn, for instance, is an abomination by conventional standards.

The philosopher and gardener Francis Bacon observed in 1625, “Nothing is more pleasant to the eye than green grass kept finely shorn.” Far from being “finely shorn” ours is mown high, at about 4-5cm max. As for grass, I reckon it accounts for about 25 per cent, the rest being made up of Bugleweed, dandelion, buttercups (all sorts), daisies, plantain, scarlet pimpernel, Black Medick, clovers, chickweed, silverweed, field woodrush, feral asters, speedwell, cowslips, oxlips, ground ivy, cranesbill, celandine, moss, bluebells and snowdrops. The orchard stays unmown, apart from paths, until late July.

Our polyfloral lawn gets no irrigation, no scarification, no chemical fertiliser, herbicide or pesticide and it supports far more living things than a conventional grass monoculture. Even if our grassland’s carbon sequestration credentials don’t match Montana’s, which cap-and-trade carbon offsets, they offer the benefits of any thoughtfully cultivated lawn, as Stephen Porder, Fulbright scholar and assistant provost for sustainability at Brown University, Providence, explains: “The world is facing a loss of species unprecedented in tens of millions of years, and one of the main drivers of that loss is disappearing habitat. Replacing a lawn, which is a biological desert, with more varied vegetation provides a refuge for myriad species in our increasingly paved over, homogenised, and biologically depauperate hometowns.”

The chemical controls needed to get rid of moss and “weeds” release carbon into the atmosphere during their production, and their application reduces biodiversity. “Perfect” lawns need irrigation. The only time I’ve irrigated is when I’ve reseeded bare patches.

I mow and therefore incur the environmental cost of the mower manufacture and fuel. And as the grass cuttings rot, they release carbon into the atmosphere. On the other hand, compost heaps need nitrogen-rich green material, such as grass cuttings, in order to rot down. And garden compost adds organic matter to the soil which feeds subterranean fungi and microorganisms and increases fertility and water-retaining properties of the soil.

Which brings me on to compost making. It is in line with the UK government’s announcement that it will ban peat from garden compost by 2024. By leaving peat in situ it can continue to store carbon. Peat-free commercial composts have improved since the 1990s, when I started using them. And homemade garden compost is therapeutic for garden and gardener alike. When I need to relax, I close my eyes and think about my compost systems: the wormery slowly and silently transforming our fish skins and cooked vegetable remains into dense nutrient-rich compost. The wormery runoff or “tea” is also an excellent plant feed.

Then there are compost heaps for kitchen and garden waste that do not attract vermin. This year’s, a layered confection of dry leaves, lawn cuttings, egg boxes, non-invasive weeds and vegetable peelings is heating up nicely. It’s twice reached a couple of metres high, only to subside to a metre as composting gets to work, reducing the bulk down to a dark, rich mulch.

A couple of months ago I added mulch from our 2019 heap to the base of a yew and beech hedges, and to the roses, hellebores and delavayi tree peonies which are rewarding us with bursts of small, scented, crimson flowers. They’d have thrived on chemical fertilisers but the long-term side effects would have degraded the soil and reduced its carbon-capturing properties.

On one level this is parochial stuff: activity on our one-and-a-quarter acres in Oxford isn’t going to make much difference either way. But the knock-on effects of what we do and don’t do in our increasingly urbanised global society are incalculable.

Bees and other pollinators support about 35 per cent of agricultural land across the world, according to a 2018 UN report. Our half dozen or so bee species buzzing around the comfrey, fruit blossom, lilac, laburnum, tulip tree, mulberry, bluebells and many of the flowers that bloom in the “lawn” all help.

Then there is the soil. Sceptics who need convincing about the drawbacks of chemical soil conditioning and feeding might look to China. According to a report in The Economist in June 2017, the use of pesticide and fertiliser in China almost doubled from 1991, and that’s on top of pollution from smelting and other industrial processes. The Economist report continues, “a Chinese government soil survey conducted between 2006 and 2011, revealed that one-fifth of Chinese farmland contains higher than permitted levels of pollutants some of which threaten food safety.” This is bad news, it concludes, for a country that has 18 per cent of the world’s population, but only 7 per cent of its arable land. 

Healthy soil is home to roughly one quarter of all species on earth. It is packed with microorganisms as well as invertebrates and insects. The connections between the living parts of the soil are subtle and profound.

On one level this is parochial stuff, but the knock-on effects of what we do and don’t do is incalculable

In his book Entangled Life, mycologist Merlin Sheldrake explores the roles that fungi and mycorrhizae play in plant nutrition, soil biology, soil chemistry and communication between trees. These themes appear in fellow scientist Suzanne Simard’s Finding the Mother Tree published in May this year. She is the heroine of Richard Powers’ novel about trees, Overstory. The first two books celebrate the mystery and importance of soil. A fourth, Dirt to Soil: One Family’s Journey Into Regenerative Agriculture, does the same from a farmer’s perspective as he wrestles his family’s chemically driven 5,000 acres in North Dakota into no-till, organic nirvana. His no-till philosophy has won him a dedicated following in the US and elsewhere.

This focus on soil has inspired communities around the world including Soil for Life, a not-for-profit in Cape Town which trains and supports people from low-income communities to create productive gardens on the sandy soil around the city.

Healthy soil better withstands drought and flooding, a contradiction explained by Mark A Bradford, professor of soils and ecosystem ecology at the Yale School of the Environment:

“Sugars and amino acids that roots and mycorrhizae exude . . . feed the free-living organisms within the soil, whose collective activities form the macroaggregates that give soil the structure of fine and larger pores that retain water in droughts, while providing effective drainage under wetter conditions which helps to ensure oxygen supply by leaving large pores with air.”

When we spoke earlier this week, Bradford celebrated the importance of gardens, especially urban ones, in adapting to climate change. In particular he talked about growing plants appropriate to the area and of keeping “armour”, or a protective layer of living or dead material, on the soil.

In other words, it is sometimes virtuous not to bother to clear leaf litter and other dead plant material. Likewise, fallen branches can be left for insect and mammal shelters. I save my energy for digging out the docks, bindweed, ground elder and other less desirable plants to which I might otherwise have applied herbicide.

Garden resilience needs vigilance on the part of the gardener. Gardens talk. If they come out in a rash of unexpected plants that’s because they enjoy hosting those plants. So, unless the incomers are unpleasant or dangerous, welcome them in. Right now Alliaria petiolata or garlic mustard is taking over our garden and a lot of the Thames Valley. Many regard it as a weed but I like its breezy pale green foliage and white flowers. By filling in gaps left by early-flowering spring bulbs, the garlic mustard protects the soil. And it is edible.

Pest intruders, which used to be seen off by sprays, dustings and pellets, now require more grunt work.

Slugs, for instance, are a constant battle, particularly during this year’s rains. Hollowed out grapefruit halves attract slugs away from slug-attracting feasts such as salad and tender curcubits. Some of the time. The water-on nematode predator is expensive and fairly effective only when used at the correct soil temperature. According to a recent paper in Nature, caffeine kills slugs so I’m chucking my husband’s coffee grounds around the salad garden. And I’m hoping that the newts, frogs, toads, hedgehogs, centipedes and ducks that live in and around our pond are eating the slugs and snails. (Hands up: I occasionally use a few aluminium sulphate slug pellets.)

Aphids are another constant enemy and the battalions of ladybirds who spent the winter in our house seem reluctant to move outside. But birds eat them and I squash them.

As our garden moves towards climate change resilience, it may lack perfect plants, “clean” beds and an emerald green lawn but the butterflies and insects hovering over our long grass, cow parsley, cranesbill, buttercups and blossom are quite as beautiful as colour-co-ordinated herbaceous borders. And they are optimistic harbingers for the future.

Climate-resilient tree species

Mark Gush, leader of the Royal Horticultural Society’s Environmental Horticulture team, has the following suggestions of climate-resilient tree species in the UK and similar climates:

• Crataegus laevigata

• Rhododendron viscosum

• Ligustrum ovalifolium

• Salix myrtilloides

• Chamaecyparis thyoides

More useful guidance can be found here: rhs.org.uk/advice/gardening-for-the-environment

Jane Owen is an FT Weekend contributing editor. Follow her on
Instagram: @janejaneowen.co.uk

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