Phil Sterling is a man on a mission – to convert every motorway embankment, every roadside verge, every unloved patch of grass in our under-resourced urban parks, even every golf course, into a flower-rich haven for wildlife – specifically our threatened populations of moths and butterflies.
Phil fell under the spell of Lepidoptera when he was just five years old. He would go moth-hunting with his father, also an enthusiast. By his teens, he was more expert than his dad, and went on to study zoology at Oxford, progressing to a DPhil on the ecology of the brown-tail moth, and a research fellowship at Balliol College.
It’s a bit like Christmas every time you open a moth trap and see how many species there are.
It is always moths that have been his first love, perhaps because they are so widely misunderstood. He regrets the common perception of moths as annoying little grey things that eat our clothes. In fact, there are only four species out of 2,500 that could possibly be culprits, and only two of these are jumper-munchers for certain. And far from being drab, moths – especially the day-flying moths, of which there are many – are often exceptionally beautiful. “It’s a bit like Christmas every time you open a moth trap and see how many species there are, all the different colours and patterns: you’re amazed at what you find.”
In 2018, as he reached his late fifties, Phil landed his dream job – working for the national charity Butterfly Conservation, offering practical advice on how to plan and manage the built environment to support wildlife, particularly butterflies and moths. But in his twenties, a scientist who wanted to work with moths had few choices: most of the job options seemed to involve exterminating them. So Phil took a left turn and became the insect expert on a team engaged in restoring grasslands. This gave him the expertise in habitat creation that stood him in such good stead when he joined Dorset County Council (as it was then) as its principal ecological adviser – a role in which he reformed the management of the county’s public realm over 25 years, enriching nature reserves and country parks, transforming denatured urban areas by planting trees and changing featureless grass areas into wildflower meadows rich in wildlife.
In a world where biodiversity is in crisis, we need to do things in a different way with our amenity landscapes, making them more permeable to wildlife.
It was Phil who designed the wildflower banks on the A354 Weymouth Relief Road (built 2009-11) that wow visitors every year with their glorious displays of blooms – shimmering sheets of yellow in spring (trefoils, hawkbit, cowslips) followed by sumptuous summer purples (including colonies of orchids) dancing with clouds of bees, butterflies and moths. It took him a while to realise that people were stopping their cars in the lay-bys not for any emergencies, but to get out and photograph the flowers. “It’s a very simple formula,” he says. “The less fertile the soil, the more flowers you get, and the more insects you can support. In a world where biodiversity is in crisis, we need to do things in a different way with our amenity landscapes, making them more permeable to wildlife.”
Standard practice in landscaping schemes is to cover the ground with a deep layer of topsoil, sow a grass mix, then plant shrubs and trees, creating a high-maintenance landscape that favours coarse grasses and needs regular mowing. But if instead a wildflower mix is sown directly on to a mineral substrate – mimicking the conditions of our richest grasslands, which always occur on the poorest and thinnest soils (such as limestone and chalk) – not only do wildflowers thrive, but the need for maintenance decreases dramatically: such grass as does arrive doesn’t grow long, and doesn’t need mowing.
“The native wildflowers we cherish – the vetches and scabiouses and knapweeds – really like being stressed: no nutrients, hardly any water. Compare that with the thistles, docks and hogweeds of this world: if you give these competitor plants rich, fertile soils, they grow big and tall, smothering and shading out all the ones that can tolerate stress. The key is to create the right environmental conditions for the stress tolerators to thrive. It won’t stop all the competitors, but they won’t be able to out-compete the others because there aren’t enough nutrients in the soil.”
The key is to create the right environmental conditions for the stress tolerators to thrive.
Some 25 species were sown on the Weymouth road verges, but many of his successful urban schemes use as few as three – bird’s-foot trefoil, ox-eye daisies and common knapweed. In addition, implementing a cut-and-collect regime for mowing existing verges has reduced grass growth, encouraged more flowers, and saved hundreds of thousands of pounds in maintenance. “You win hearts and minds by showing people results – and good results were very quick to arrive,” says Phil. The tally of plants on the banks now exceeds 140, while over 30 species of butterfly – half the total number of species in Britain– have been recorded. National Highways has now adopted his methodology as a template for road-verge design, but Phil is far from thinking his work is done. He would really like a policy role in which he could influence government thinking. “We now have the evidence that reversing biodiversity loss actually saves money: that’s a message that more people need to hear.”
Useful information Butterfly Conservation’s Big Butterfly Count runs from 14 July to 6 August: bigbutterflycount.butterfly-conservation.org