Mowing less does more good

            Farmers, gardeners and others whose livelihoods depend on a healthy population of wild bees to pollinate cultivated crops and other plants have become increasingly worried in recent years. The global decline of bees – due to pesticides, climate change and natural parasites and pathogens – has led to reports that the world food supply may be threatened, along with millions of jobs and an unknown number of ecosystems.

            As worrisome as it is, there appears to be little that most of us living regular lives in suburbia can do to improve the situation. Yes, we can plant native pollinator gardens to provide

nectar to bees and butterflies in our yards. And if you haven’t already done so, then I encourage you to take that step. But not everyone has room for a garden or the time and money and physical ability to plant and maintain one.

            But recent research by an urban ecologist in Massachusetts suggests that there is an even easier step we all can take to benefit local bees. And rather than requiring that we do something more, it instead requires that we do less than most of us already do.

            Susannah Lerman at the U.S. Forest Service’s Northern Research Station in Amherst sought to determine whether lawns could somehow provide useful habitat for bees. So she spent two years regularly visiting 16 suburban lawns in Springfield, Mass., some of which were mowed weekly and others every other week or every third week.

What she found was quite surprising.

            During her visits to the lawns – none of which were treated with pesticides or herbicides – she discovered 64 flowering plant species growing among the blades of grass, including dandelions and clovers, of course, but also violets, smartweed, cinquefoil, rockcress and others considered by everyone to be wildflowers. These “spontaneous flowers,” as she called them, were not intentionally planted, but they still provided an abundance of pollen and nectar to bees.

            What was even more surprising is that Lerman and a colleague collected and identified 111 different kinds of bees on the properties. That’s about one quarter of the total number of bee species ever found in Massachusetts. One yard had an amazing 53 species. And even more astonishing than that – the most abundant species of bee was a sweat bee that had not been recorded in the state since the 1920s.

            So how can we do less to help our local bees? By mowing our lawns less often, Lerman said. It turns out that the lawns with the largest number of bees on them were the lawns mowed every two weeks instead of every week. That extra week in between mowing allowed some of the slower-growing spontaneous flowers the time they needed to bloom and provide nectar to the bees.

            Lerman concluded that the best thing most homeowners can do to reverse the decline in bees is to forego the use of chemical lawn treatments, plant a pollinator garden if possible, and only mow the lawn every other week at most.

            Some of the lawn-obsessed among us may find it challenging to follow these suggestions because they see dandelions and clovers as weeds. But Lerman told me that “we need to change their perceptions and show that those plants are really providing wildlife habitat.”

            So do a little less to your lawn this year, and feel good that you’re actually doing a little more for your local bees at the same time.

This article first appeared in the Independent on May 22, 2017.