Putting the toothpaste back in the tube

At a time when we’re wondering whether what’s broken can ever be fixed, it’s nice to hear some good news about planting for pollinators. A team of scientists in Munich recently published results of their study of urban flower strips, 1,000-square-meter wildflower gardens planted in the city as part of the European Union’s initiative to improve foraging opportunities for bees and other flower-visiting insects. They found these plantings surprisingly effective.

Urban flower strip, Fockenstinstrasse, Munich

    The team undertook their study when the flower strips, sown with a mix of locally native flowering plants, were only a year old. They hypothesized that these mini-meadows would draw mostly bees that are common in Munich and can gather pollen from a broad range of flowers. They didn’t expect these beds to be much of a resource for oligolectic bees, ones that need food from a few native plants. They got a surprise. 

Dogwood andrena bee specializes on dogwood flowers-photo Beatriz Moisset

    In the first year, 61 percent of the bee species known to live in Munich found the flower strips. Most were the common polylectic types, the bees that aren’t picky foragers. But the proportion of specialist  bees that needed particular flowers was nearly the same as in Munich's general insect population. They also found that the urban flower strips increased bee populations in surrounding areas, as far as 1500 meters away.

European dark bee-photo SJ Richards

    By the way, were any bees killed in the process? I was glad to hear that this was a catch and release program. The scientists swept the air with insect nets, put the bees on ice for 10 minutes, and when the bees entered “cold rigor,” they measured and photographed them on site. Within two to three minutes, when the bees had warmed up and awakened, they released them to continue foraging.

    As I prepare to plant native perennials to attract pollinators, this study gives me confidence that my efforts can be effective. Germany’s situation is a lot like ours. The scientists noted that Germany had lost about 10 percent of its meadows between 1991 and 2019. We too are losing open space at a great rate, estimated by the US Forest Service at 6,000 acres every day, or 4 acres per minute. 

Goldenrod provides insect forage in a Maine meadow

     What’s left may be so altered by human activity that it doesn’t offer much of what native insects need. We know that insect populations are plunging. Our government lags behind the European Union’s in addressing this. That’s why there’s such an urgent need for home gardeners to plant for flower-visiting insects.

Pollinator garden at the Smithsonian's National Museum of Natural History

    But can we really replace the rich biodiversity of what’s lost?  I worry that my small effort will offer too little too late. This study suggests that our pollinator gardens can make a meaningful contribution toward rehabilitating impoverished landscapes. I’m hoping my new bed of native pollinator plants will be attractive and full of insect life. It would be nice if it also drew not just the toughest survivors, but also the insect species that need the most help.

Spotted beebalm in my pollinator bed should support native insects-photo Judy Gallagher