Study: Small Gardens Are Just As Crucial for Bee Conservation As Big Ones

Whether it’s leaving hollow plant stems as nesting sites or making a watering hole for native bees, Treehugger is not short of tips and tricks for more pollinator-friendly gardening practices. Yet if you have only a small, urban garden to tend, it can sometimes be tempting to wish for a lot more space with which to help our furry, flying friends. It turns out, however, that size doesn’t matter all that much. 

At least, that’s the findings of a paper, titled "Turnover in floral composition explains species diversity and temporal stability in the nectar supply of urban residential gardens," recently published in the Journal of Applied Ecology. Nicholas E. Tew of the University of Bristol and his team found—based on a survey of 59 urban gardens in Bristol, England—that while the amount of nectar produced by urban gardens varies widely, the variation has little to do with the size of a garden. Instead, factors like gardening practices and, interestingly, the relative wealth of a neighborhood were much more closely correlated.

The study also found that not only are urban gardens a critical source of food and habitat for pollinators but that no single garden is a haven by itself. Instead, they are best seen as a patchwork of resources which, when combined together, become more than a sum of their parts. 

Tew, the lead author, told The Guardian one of the main reasons why size is less important than management practices is simply that the vast majority of nectar production occurs around the edges of gardens, in the form of shrubs and other landscaping plants. Because the majority of British gardens big and small are made up of lawns and/or hardscaping, the size of the plot itself is unlikely to have a huge impact on nectar supply. 

Does this equation change when lawns are managed differently? Tew told Treehugger via email:

“Lawns can provide a lot of food if they are managed to be very flower rich (cut less frequently and soil not fertilised). We found very few gardens where lawn flowers made up a large proportion of nectar resources partly because so few were flower-rich (huge room for improvement), but also because shrubs can have so many more flowers in a small space. Replacing lawns with more borders and flowering shrubs would increase the food supply, but letting lawns grow long and flowery can be great for nectar and other resources (e.g. bumblebee nest sites and caterpillar foodplants).”

The study was conducted in Bristol, England, which raises the question of whether its findings can be applied across the globe. Tew explained to Treehugger that, while certain specifics may differ, the broad principles likely apply.

“While the precise shape of the seasonal nectar supply curve and the contributions of specific plant taxa will differ in other cities and years," said Tew, "the general findings of extreme variability and turnover among single gardens but temporal stability across multiple gardens are very likely to apply in other cities because the principle that gardens comprise many small habitat patches which differ independently in their management remains true wherever they are located.”

As for what gardeners can specifically do, Tew suggested prioritizing shrubs, climbers, and trees—these made up for the majority of nectar supply in the study. He also encouraged the planting of deep, tubular, open flowers that become important later in the year for hoverflies and solitary bees. And he recommended ensuring both year-round flowering and a variety of different habitats to support pollinators at different stages of their lifecycles. 

Unsurprisingly, the research backs up much of what Treehugger permaculture expert Elizabeth Waddington has been advising in her articles. Whether it’s choosing bee-friendly plants, designing and maintaining a garden for bumblebees, or letting your lawn become a little less manicured (and a lot more interesting!), the general principles appear to encourage diversity, be OK with a little mess, and plant a whole bunch of flowers. 

Seems easy. And now that we know that we can do it on any scale and actually make a difference, there’s even more reason to get started next spring.