Gardens packed with blooming flowers or adorned with neat insect hotels, are extremely popular. But are these highly curated creations actually helpful

Turning your entire plot into a wildlife garden is a boon for biodiversity, but it’s not an attainable goal for everyone. According to a recently published study Narango co-authored, converting at least 70% still makes a notable difference. It considered the impacts native and non-native landscaping have on food availability for birds (largely insects), and found non-native plants do reduce insect count, which ultimately impacts bird population growth. But there’s a silver lining: “We were able to identify a threshold so that we could provide targeted [non-native plant] goalposts for people to strive for,” says Narango. The researchers found that if more than 70% of your garden’s biomass is native, that allows birds to sustain their populations.

Doing less with your garden and letting things get a little messy, especially during strategic times of year, such as early spring, can help to protect emerging wildlife. For example, the international campaign No Mow May encourages people [in the Northern hemisphere] to stop mowing for the entire month of May, to allow plants to bloom and set seed without being flattened or decapitated.

However, Susannah Lerman, a research ecologist for the United States Department of Agriculture’s Forest Service Northern Research Station and adjunct professor at the University of Massacresetts in Amherst, US, prefers the term “Slow Mow Summer”. Her research on the effects of mowing frequency found that mowing less in general leads to more flowering plants and therefore more bees.

“A lot of [pollinators] are ground-nesting bees, so actually not mowing until April or May is a good thing, because it allows them to come out of their winter nesting grounds. So, there are benefits to a little bit of neglect,” says Miller Helmholdt.

There are benefits and challenges to letting your garden go completely.

For one thing, in the absence of human intervention, the most aggressive, non-native species have an opportunity to take over. “When you have hyper-aggressive plants, that’s the enemy of diversity, because they outcompete a lot of what could have been there,” says Larry Weaner, an ecological landscape designer and founder of Larry Weaner Landscape Associates Designs, based in Pennsylvania. What you’re left with is a more homogenised garden, which is not great for native pollinators who might be struggling to sustain their population. “You might get an overabundance of some weedy species that might look like they’re good for bees, but in reality, are not doing very much,” says Narango.

Shepherd says the result could be a “tangled mess” that “will provide some food and shelter, but I’d expect its overall value for wildlife will be less than if it were a tended plot supporting a greater diversity of native plants.”

However, there are totally neglected landscapes that have seen wildlife proliferation. Some so-called brownfield sites – areas of land that previously had a commercial or industrial use – such as defunct and derelict factory properties, are now home to endangered species in the UK. This includes the distinguished jumping spider, which enjoys salty, sandy environments, and is found at just two locations – both brownfield sites near London.

Though brownfield sites were never managed gardens, they demonstrate how, when properties are just left, “there were lots of opportunities for plant communities to reoccupy the sites,” says Shepherd. Similarly in the US, Detroit’s industrial decline led to a multitude of abandoned sites that now teem with wildlife.

While experts recommend doing a little less mowing and pruning in the spring and summer, it’s also recommended to let some things pile up in the autumn, specifically leaves. The Xerces Society for Invertebrate Conservation, a non-profit organisation focused on the conservation of invertebrates, promotes an initiative called Leave the Leaves that advocates for this to protect insects that overwinter on your property.