We often feel helpless in the face of huge, global conservation issues such as climate change, tropical deforestation or the demise of polar bears as the ice melts. Any individual actions we might take seem trivial, too diffuse to make any appreciable difference, and the events are often unfolding in faraway places where we cannot imagine having any direct influence. Thankfully, conserving our insects is something with which everyone can get directly involved, and feel they are making a tangible difference.
Unlike polar bears, insects live all around us, in our gardens, city parks, allotments, cemeteries, on road verges, railway cuttings and roundabouts, and these are places that are relatively easy to make more insect-friendly. Gardens alone cover about half a million hectares of the UK, a bigger area than all of our nature reserves, and one that will only expand with proposed house building in the coming years. Our gardens are linked together by these urban green spaces, and our villages, towns and cities are linked by road verges, railway cuttings and embankments. The UK alone has a quarter of a million miles of road verges. There is an opportunity to swiftly turn our cities, towns, villages and gardens into a buzzing network of insect-friendly habitats.
The most obvious step that gardeners might take is to plant some pollinator-friendly flowers. It is very easy, and there is an abundance of advice available, albeit not always 100 percent reliable. Many lists of pollinator-friendly plants have been published. In the UK, for instance, the advice published by the Royal Horticultural Society, available online, is among the most exhaustive and reliable.
Garden centers often flag up pollinator-friendly plants with labels, usually adorned with a cartoon bee logo. Broadly, in the temperate northern hemisphere, you won’t go far wrong if you fill your garden with old-fashioned cottage-garden plants and herbs, such as lavender, rosemary, marjoram, comfrey, catmint, thyme and hardy geraniums (do not confuse the latter with the related Pelargonium, which are useless for our native insects, being adapted for pollination by long-tongued flies found in southern Africa).
Squeeze in some native wildflowers too if you have room; in Western Europe, foxgloves, viper’s bugloss, or white deadnettle are great choices, but there are many more. Some native plants produce beautiful flowers, and are also the food plant for caterpillars of butterflies: in the UK, bird’s foot trefoil and lady’s smock, for example, provide food for the caterpillars of common blue and orange tip butterflies, respectively.
Avoid annual bedding plants such as busy-lizzies, begonias, petunias and pansies: these plants have been intensively bred to produce large and colorful blooms, but in the process they have often lost their scent or nectar, or the flower shape has been so altered that insects cannot enter, so they tend to be pretty hopeless for insects. Also steer clear of double varieties of flowers such as roses, cherries, hollyhocks and aquilegia, since these are mutants which produce extra petals instead of pollen.
If you only have a tiny garden do not despair, for even a balcony or roof terrace can provide food for pollinators like bees and hoverflies; on the tenth floor of a city-center building I have seen bumblebees turning up, regular as clockwork, ferrying food back to their nest hidden somewhere in the urban jungle. A few herbs such as marjoram or chives in pots will draw them in, with the added bonus of providing a tasty addition to your cooking.
If you have a lawn, a second, simple step to making your garden into an insect paradise is simply to mow a little less often, saving petrol and your own time. You might be surprised by how many flowers pop up: buttercups, daisies, dandelions, clovers, selfheal and bird’s foot trefoil are all commonly found in lawns, but with regular mowing they never get to flower. Ease off for a couple of weeks and flower buds will soon pop up and open, drawing in a crowd of insects.
Of course, to some tidy-minded gardeners these lawn flowers are “weeds,” to be grubbed out manually or sprayed off with herbicide. I have never grasped why some folk are so desperate to have a perfectly uniform, green lawn, unmarred by pretty flowers. The concept of a “weed” is entirely within our heads; one man’s weed is another’s beautiful wildflower. If we could somehow engineer a shift in attitude, so that “weeds” such as daisies or clovers were seen as desirable additions to a lawn, rather than enemies to be battled against, we would save ourselves an awful lot of time, money and stress, while helping nature into the bargain.
Relating to this, you could also make your garden a pesticide-free zone. There is simply no need for pesticides in the garden, and why would you want to bring poisons into the place where your children play? I speak from experience, for I am lucky enough to have a two-acre garden full of flowers, fruit, vegetables and wildlife, all living in approximate harmony without any artificial chemicals. If you discover a few aphids or whitefly, leave them be, for they are food for lacewings, ladybirds, earwigs, hoverflies and blue tits. Probably they will be eaten soon enough, and if not, it is unlikely they will do too much harm. If you have a plant that is routinely infested with pests then it is a certain sign that the plant is not happy; simply try growing something more suited to the conditions in your garden.
If you would like your garden to be pesticide-free, you should also be wary of the pretty flowers on sale in your local nursery. Sadly, the large majority of garden centre plants, including those labelled as “bee-friendly,” have been treated with insecticides and other pesticides, and the residues are often still present. We discovered this in my lab in 2017 when we screened a selection of UK garden centre plants for pesticides. Ninety-seven per cent of the plants labeled as bee-friendly contained at least one pesticide, with 70 per cent containing neonicotinoid insecticides. The latter are now mostly banned, but I’d be willing to bet that they have been replaced with other insecticides. Far better to buy from an organic nursery (you can find some online), or grow your plants from seed, or plant-swap with friends and neighbors. These options also avoid the environmental cost associated with the peat-based compost that many ornamental plants are grown in, the fertilizers used on them, and the plastic pots they are sold in (most of which are never used again).
While you are at it, you might also write to your local council and ask them to stop spraying pesticides in your local park, and along the road verges and pavements. You might even urge them to phase out pesticides entirely. Thirty years ago, the small town of Hudson in Quebec, Canada (population 5,135), became the first place to ban pesticides. The ban came about thanks to the dedicated efforts of a local doctor named June Irwin, who became convinced that health problems she was seeing in her patients were linked to heavy pesticide use in gardens. She attended every town council meeting for six years to raise this issue, and her dogged determination eventually paid off, with the council introducing a bye-law banning all chemical pesticides within the town limits.
Hudson has since been followed by 170 towns across Canada, including major cities such as Toronto and Vancouver, while eight of the ten Canadian provinces have banned all cosmetic use of pesticides. Thanks to June Irwin, 30 million Canadians now live in pesticide-free areas. Towns elsewhere in the world have followed, from Japan to Belgium and the USA. France has taken the concept to heart, with 900 towns declaring themselves “villes sans pesticides.” That then prompted the government to ban all non-agricultural uses of pesticides nationwide from 2020. Only registered farmers are now allowed to buy them. The UK has been somewhat slower to pick up on this movement.
A number of UK towns and cities have pledged to phase out pesticide use by their local authority, including Brighton, Bristol, Glastonbury and Lewes, and also the London borough of Hammersmith & Fulham, but there seems to be no appetite to restrict domestic use. Surely if the entirety of France can manage without any pesticides in urban areas, we can follow suit? It seems to me that there is little or no downside to doing so, unless you are a manufacturer of pesticides or sell them from your superstore. The upsides, of course, would be more urban biodiversity, and no chance that we or our children would be exposed to these toxins—which include suspected carcinogens—when playing in the garden or in the local park.
There are many other small steps the gardener can take to make their plot a little wilder and a little richer in life. Ponds are wonderful, attracting all sorts of insects such as dragonflies, pond skaters and whirligig beetles, along with amphibians like newts, frogs and toads if you are lucky. Even tiny ponds seethe with life, and provide a place for birds to drink and bathe. Create a compost heap to recycle your own organic waste and you will be giving a home to a myriad tiny creatures, from springtails to tardigrades, millipedes and woodlice, as well as producing your own beautiful rich compost, negating the need to buy compost in plastic sacks from the garden centre. If you have room, sow a wildflower meadow of your own, or plant a flowering tree like an apple, cherry, willow or lime.
Finally, you might try providing homes for some types of insects in your garden. A lot of fairly useless “bug hotels” are sold in garden centers: for example, butterfly hibernation boxes are commonly sold, but field tests of 40 such boxes over two years by scientists at Penn State University in the USA found zero occupancy by butterflies (though quite a few contained spiders). On the other hand, “bee hotels” that aim to provide homes for solitary bee species often work remarkably well. Bees like red mason bees and leafcutter bees simply need horizontal holes to nest in. You can easily make a hotel for them yourself, by drilling holes of between 6 and 10 millimeters diameter into a block of wood, or by tying bundles of bamboo together.
Some fancy commercial designs have windows that allow you to peek inside to see what is happening in the hotels, which is fascinating for adults and a great way of getting children interested. Occupancy of bee hotels is a bit hit-and-miss, depending on whether you have the right species of bee nearby, but it can be high; I often get 100 per cent of the holes occupied. You might also provide a “hoverfly lagoon,” a miniature pond in an old plastic milk bottle or similar: fill it with water and a handful of lawn clippings or leaves, and hopefully it will attract some beautiful hoverflies to lay their eggs.
Of course, in our crowded and urbanized modern world, many people don’t have any kind of outdoor space to call their own. If so, you might be feeling frustrated by all this talk of gardening, but you can still get involved. You could follow the example of a group of weekend conservationists based in Stirling, Scotland, who call themselves On the Verge. They spend their weekends digging over any piece of mown, boring grass they can get their hands on, and sowing it with wildflowers—with the permission of the owner, of course. There are now 82 patches of wildflowers dotted around Stirling and the neighboring county of Clackmannanshire, on road verges, roundabouts, parks, school fields, and even one in a prison yard. I had a keen undergraduate student named Lorna Blackmore survey these wildflower plots, comparing them to neighboring patches of mown grass. Lorna found that the sown patches had 25 times more flowers, 50 times more bumblebees, and 13 times more hoverflies than the mown grass they had replaced. Wouldn’t it be amazing if every city and town had a similar scheme, so that all our urban areas were peppered with wildflower patches?
More generally, most local authorities manage an awful lot of land that could be rich in wildlife, but is currently not. If we can persuade them to come on board, there is vast potential. Our parks could have meadow areas, beds planted with pollinator-friendly flowers, wildlife ponds, flowering and fruiting trees, bee hotels and hoverfly lagoons. Every roundabout could become a glorious riot of wildflowers. Cemeteries can be hugely rich in wildlife if they are managed sensitively; some older ones have a diversity of flowers to rival an ancient wildflower meadow, while in contrast others have been strimmed, mown and herbicided into tedious, neat submission.
Local authorities have it within their power to stipulate that all new developments include places for nature, to promote green roofs and tree-planting, and they could protect those brownfield sites that have become rich in wildlife. Our urban areas are often fringed by golf courses, which cover about 2,600 hectares of the UK (Surrey alone has 142). Most golf courses are approximately 50 percent fairway and green, and 50 per cent rough grassland and woodland, the latter with huge potential for wildlife. Some already support considerable biodiversity, but many are poor, planted with non-native trees and subject to heavy use of pesticides and fertilizers.
When granting permission for a new course, local authorities could stipulate that they must be pesticide-free, and that all rough areas must be managed for wildlife, with wildflower meadows and copses of native trees or other native vegetation as befitting the location. Perhaps we could also gently rewild our existing golf courses, taking them back to something more like the ancient golf courses used when golf was first invented in the 16th century.
Greening our urban areas would have obvious benefits for insects, for wildflowers, and for the many animals that feed upon insects, but what is perhaps less well understood is how beneficial this might be for us humans. More than a hundred years ago Octavia Hill, one of the founders of the National Trust in the UK, said that “The sight of sky and things growing are fundamental needs, common to all men.” In his book Biophilia (1984), the famous American biologist E. O. Wilson argued that humans have an innate instinct to connect emotionally with nature, and that being unable to satisfy that instinct may impact on our well-being.
Not long after, a new field of psychological research began to emerge, coined “ecopsychology” by Californian academic Theodore Roszak, which explores the effect that our ever-diminishing interactions with wild nature have upon our psychological development and well-being. A common contention is that if society is disconnected from nature, then various aspects of an individual’s life will be negatively impacted, even to the extent of leading to delusions and insanity.
Subsequently, the American author Richard Louv argued in his book Last Child in the Woods (2005) that many children growing up in gray, urban environments suffer from “nature deficit disorder,” a suite of behavioral problems brought on by lack of opportunity to play outdoors, in nature. He claims that these problems include attention deficit disorder, anxiety, depression, and a lack of respect for the environment and other life forms. Echoes of these arguments can be found in Feral (2013), by the British environmentalist George Monbiot, which promotes the idea that humans have a primal need to experience wild nature.
This all sounds very interesting, and seems like a powerful argument for looking after nature, but where is the evidence? Will we really be anxious, depressed, deluded and insane if we don’t get a regular dose of nature, or is this just wishful thinking by environmentalists keen to bolster their cause? Alternatively, is it possible that humans could live perfectly happy, contented lives without ever seeing a blade of grass or hearing the sound of birdsong?
While not every claim made for the benefits of encountering nature stands up to scrutiny, many empirical studies have now been performed, variously by medical researchers, psychologists, social scientists and ecologists, which demonstrate beyond doubt that contact with nature does indeed broadly do us good. Just 15 minutes spent walking in nature has been found to leave subjects with improved attention and sense of well-being, compared to subjects asked to walk in heavily urbanized areas. Even watching a video of nature gave significant benefits, though not as much as experiencing the real thing.
Other studies have found that stress levels of Scottish city dwellers were lower in those living near green space, while in the Netherlands anxiety disorders and depression are less common in those living in urban areas with more parks. In California, people living in areas with more urban tree cover tend to be less fat, and less likely to have diabetes and asthma, having controlled for other factors such as wealth. Expectant mothers living in more green neighborhoods tend to give birth to heavier infants. Hospital patients with a view of greenery get well more quickly than those with a view of a brick wall. Having a green view from home improves the cognitive functioning of children and the mental well-being of adults. A simulated drive to work through a rural landscape left people better able to cope with subsequent stress in the workplace, compared to those that drove through a virtual urban landscape.
Various studies have found that gardeners and allotmenters have a higher level of satisfaction with life, higher self-esteem, better physical and mental health, and less depression and fatigue, compared to non-gardeners. Going on expeditions or camps to wilderness increases multiple measures of mental well-being and connectedness to nature. There are many more, similar studies, but I think I have probably bombarded you with enough examples to make the point: we humans seem to be healthier if we have access to, or sight of, greenery.
As a result of this growing body of evidence, doctors in New Zealand and Australia, and recently in the UK, have started giving “green prescriptions” to some patients instead of the more traditional drugs. A green prescription usually takes the form of prescribing a regular walk in a park or the countryside, or sometimes taking part in a tree-planting scheme or other outdoor activity. Of course, the exercise itself provides a large portion of the benefit, but the combination with going out into nature appears to be most effective, and more likely to be stuck to by the patient than simply telling them to go to the gym. In Japan, “forest bathing” (simply spending time in woodland, with no swimming required!) is commonly recommended by doctors, and appears to have multiple health benefits including boosting immune function.
You might have spotted a flaw in this argument so far. The evidence links human well-being to access to green space, but there is not much known about the quality of that space. Perhaps a boring mown lawn and a Leylandii hedge would be enough? Maybe Astroturf and plastic flowers would do the job? Does it soothe our soul and reduce our blood pressure more if there are wildflowers, butterflies or birds? There have been remarkably few studies that have attempted to test whether the quality of green spaces, in terms of their biodiversity, positively affects human health, but those few that have been carried out mostly found that more biodiversity is indeed good for us. Both plant and butterfly diversity of green spaces have been found to have positive effects on measures of human well-being, but bird diversity seems to be the aspect of biodiversity most strongly linked to human health, especially that of songbirds. Intriguingly, one UK study found that observers got more pleasure from watching the birds in their garden if they could name them, reinforcing the argument that people are more likely to care for and empathize with nature if they can recognize it.
One interesting idea is that exposure to a biodiverse environment inoculates us with a more diverse and healthy microbiome, as we call the flora of microbes that live on and in us. Exposure to beneficial microbes during early life has powerful effects on the development of the immune system and reduces the prevalence of chronic inflammatory diseases. Urban dwellers have, on average, a less diverse microbiome, so there does seem to be a plausible link between human health and exposure to microbially diverse environments. There is also some evidence that a high diversity of trees and shrubs provides a more dense canopy, which is better at filtering out air pollution.
Overall, there seem to be immense health benefits associated with providing people with access to green space, and it is likely that these benefits are greater if the area is rich in biodiversity, while knowledge about nature may increase the benefits even further. Inviting nature into our cities and towns would seem to be a simple win-win: good for nature, and good for us. Imagine if every garden was brimming with pollinator-friendly flowers, including native wildflowers, with a mini-meadow, flowering shrubs, a pond, compost heap, bee hotel and a hoverfly lagoon tucked in the corner. This would provide a mosaic of tiny insect nature reserves, which if local councils came on board could be linked by flower-rich road verges and roundabouts, by lines of flowering trees in the streets, by flowering railway embankments, city nature reserves, nature areas in school grounds, city parks and so on, providing a network of interlinked habitats stretching across our crowded country.
All new developments would be designed from scratch to maximize biodiversity and public access to green spaces. It seems to me that this is easily within our reach; some of it is happening already, with councils and local authorities banning pesticides and developing plans for helping pollinators, and many a gardener quietly turning their patch into a mini-nature reserve.
Our urban areas could soon become, not just places for people, but places where people and nature live happily and healthily alongside one another, where green leaves and flowers are visible in all directions, where children can grow up surrounded by the familiar buzzing of bumblebees, and where they could learn the names of birds and bees and admire the flashing colors of a butterfly’s wings.
Excerpted from Silent Earth by Dave Goulson. Reprinted with permission by the publisher, Harper. Copyright © 2021 by Dave Goulson.