Lighting is a crucial part of garden and landscape design. Lights are used to extend the hours of use in the garden, light driveways and pathways to make them safe and for general security. However, all artificial lighting has an effect on wildlife and the local ecosystem, so it is important to light gardens responsibly.
"All living things, including animals, plants and microbes, have evolved under a natural rhythm of night and day," says garden designer Rachel Bailey MSGD. "As the world has rapidly become urban and light pollution extends into rural and offshore areas, the distinction between night and day has become blurred."
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Artificial light at night, also known as ALAN, has wide-reaching effects on the organisms around it. DarkSky International, the global organisation combatting light pollution, said in its annual report that "ALAN is one of the most pressing and imminent threats to global biodiversity."
Adding that "studies suggest clear impacts on wildlife populations due to artificial light, even from indirect exposure." Insects and birds are particularly susceptible to the effects of artificial lighting, but the impacts are felt across all types of animal and in plants too.
Artificial lighting affects normal foraging, migration, reproduction and predation. Moths, for example, are drawn to artificial lights, which prevents them from carrying out usual pollination activity at night and often leads them to tire themselves out and perish.
Kate Bradbury, award-winning wildlife writer, echoed Rachel's thoughts, saying: "Artificial lighting can be disastrous for wildlife, from moths and bats that are distracted from feeding and mating, to robins and blackbirds that don't sleep and instead exhaust themselves by singing through the night, to the many insects sheltering in trees and foliage that become disorientated and can't complete their lifecycles."
There are steps that we can take to reduce the impacts of artificial light. In September 2024, Lahiti, a city in Finland, began a trial of pollinator-friendly street lamps which filter out light in the blue spectrum, which pollinators are especially drawn to. Twelve lights have been changed in the trial, and if successful the city will update other areas where pollinator activity is high to try and increase night-time pollination rates. These swaps, if proved successful, could be rolled out across larger areas in cities and adopted by individuals to cause a wide-reaching reduction in the impacts felt by wildlife from artificial lights.
"The more research is done on artificial light, the more we realise how bad it is," says Kate. "Both diurnal and nocturnal wildlife need darkness, and, while cities, streets and other areas are lit up throughout the night, it's up to us gardeners to provide darkness."
Rachel agrees, saying: "Given that gardens make up around double the area of managed nature reserves in England, Wales and Scotland combined, gardens can provide a refuge for wildlife if the inclusion of lights around our houses and gardens is considered carefully."
"People are often surprised when they hear that lighting impacts wildlife," she adds. "We have a long way to go given the conversations I have had with many people who want wildlife-friendly gardens but also ask for lighting. As designers and garden makers, we can do a lot more to inform people of the impacts of lighting on wildlife as well as design the gardens."
Our gardens are spaces that we share with wildlife, so it's important to consider what these creatures need from them. "That's not to say we gardeners can't enjoy our gardens at night, we just need to do so more mindfully," says Kate.
"If you want to light your garden in the evenings, use soft, yellowish light rather than bright white light, as this is thought to be less harmful to wildlife. Turn the lights off when you're not using them and avoid hanging lights from trees or shrubs where insects may be sheltering, and light only the area you're using," she adds.
"Perhaps it's time we humans reconnected with the moon and the stars? Embrace your garden at night, use the least amount of light you need to. What's wrong with a bit of darkness at night time?"
Rachel's tips on lighting the garden responsibly
Consider whether you need lights, and where
"Consider carefully whether you actually need lighting in your garden or in all parts of your garden," says Rachel. "For paths and access to the house the answer is probably yes; and perhaps for where you sit and entertain or hang out in the garden at night. But do you need your garden to be lit up like the Blackpool illuminations or have lights on all night? Probably not." For Rachel, less is more when it comes to creating a mood in the garden.
How do you control your lights
"Avoid PIR motion sensor lights, dawn-to-dusk and lights timed to come on/off every night. Rather group your lights based on their function," says Rachel. "For example driveway and front door lights, pathway lights in back garden, dining area - that way you can switch the lights on when in use and then back off when they are no longer needed, minimising impact of lighting on wildlife."
Light intensity
Rachel recommends only using warm or warm white (2700K and less) lights. "Keep the brightness of the lamp (bulb) to a minimum, for example 75 to 95 lumens would be fine for lighting a feature, whereas way-finder path lights at 2 to 4 lumens each would light the way. Direct light downwards up to the horizontal plane, and never point the light upwards."
Dark areas and buffer zones
Our homes often border areas of habitat and our gardens are habitats too. It's important to make sure, if you do use lights in your space, that they are contained and don't spill into surrounding areas. "If you include some lights, leave as large an area as possible dark and add buffer zones between your garden and neighbouring habitats," advises Rachel.
Video credit: © Getty / Varunee Somwat
