I was very young when I first tasted spinach, but I had enough sense to spit it out. In fact, I let it drool down my bib and I threw it off the edge of the high chair so that my mother would fully understand my displeasure. At the time, I was equally distrustful of strained peas.
That’s just about how native insects react to non-native plants, with equal parts of suspicion and revulsion. The more we learn about nature, the more we look back and regret what we used to do. It turns out that our penchant for planting non-native flora has made our backyards both attractive and sterile. Most bugs won’t eat the unfamiliar vegetation. Perhaps that’s a good thing. But if there are no bugs, there are no birds.
Maybe it’s the approach of gardening season that has made me sensitive to the topic. A few weeks ago, Dick Andren of Dixmont sent me a column from the New York Times. Dick is a board member for Hirundo Wildlife Refuge in Old Town. The column was the work of Douglas Tallamy, an entomologist and wildlife ecology professor at the University of Delaware.
Tallamy cited eye-popping research that 96 percent of terrestrial birds in North America feed on insects at some point. Even birds that typically dine on seeds and berries will seek out insects for their young because fledglings need the extra protein to develop. Chickadees are seed-eating champions, but it is estimated that they need 6,000 to 9,000 caterpillars to feed one clutch of nestlings.
That’s the kind of abundance that is not found in exotic gardens. In one backyard, observers counted 410 caterpillars of 19 different species in a native oak tree. A native black cherry harbored 239 caterpillars from 14 different species. A nearby non-native Bradford pear had only one species on it — an inchworm.
A healthy, native tree will contain lots of insects. It’s a natural battle between long-time adversaries that has been going on for eons. Native plants have their own defenses, and they have allies. Yards with insects are yards with birds. They often devour the pests as fast they reproduce. Native insects do not defoliate native plants. Everything is in balance. Nature only gets out of balance when non-native species are introduced. These can be exotic, inedible plants or voracious, not-too-picky Japanese beetles.
This probably wouldn’t be a major problem except for another change that has happened since I started spitting out baby food. In my time on Earth, the U.S. population has doubled. Suburbia has gobbled up woods and fields, and we often view our yards the way most of our immigrant forebears did. It is a European trait, particularly English, to view nature as something that needs taming. We crave the orderliness of manicured lawns.
Furthermore, trimmed grass and neat flower beds were considered signs of wealth and social status. Old cultural habits die hard. If you lined up all of the lawns in America, they would cover eight New Jerseys. Small wonder that the population of bird species is declining about 1 percent per year.
I used to think that humans came to dominate the Earth because of superior intellect. Now I think it is more likely due to having opposable thumbs. We always seem to be in a race to correct our mistakes before they overwhelm the planet. Such is the case with a new trend in gardening called “yardening.”
Gardening is the top outdoor leisure activity in the United States, according to many surveys. A subset of gardeners has taken up the challenge of returning yards to a more natural condition, emphasizing native plantings and habitat diversity. They are being rewarded with the return of birds and wildlife. It turns out that it is not that hard to share the planet with other species.
Some communities are taking the trend to a whole new level. Entire neighborhoods have assumed the challenge of making their yards into a contiguous bird-friendly habitat. When habitat is fragmented into small pieces, nothing good happens. But when full neighborhoods go native, the native birds and butterflies return.
I’ll offer more in a future column, but there is no need to wait. Hirundo has lined up Lisa Coburn for a plant talk 7 p.m. Wednesday, April 29, at the Old Town Museum. Lisa created the Maine Garden Journal and blogs at mainegardenjournal.com.
A yard with flowers is beautiful. A yard with flowers, birds, and butterflies is more beautiful. Now, please pass the spinach.
Bob Duchesne serves as vice president of Maine Audubon’s Penobscot Valley Chapter. Bob developed the Maine Birding Trail, with information at mainebirdingtrail.com. Bob can be reached at duchesne@midmaine.com.