gardeninacity

Is gardening a crusade or a hobby? This question occurred to me after reading a New York Times article about a symposium featuring Douglas Tallamy, Chair of Entomology and Wildlife Ecology at the University of Delaware. Tallamy is also the author of “Bringing Nature Home”, in which he argues for the environmental importance of using native plants in home landscapes.

In his presentation, Tallamy maintains that gardens should not be judged on beauty alone: Gardens should, among other things, help sustain the diversity of life.

Tallamy’s argument is all about insects. His research shows that native plants support way more insects than exotics. To give just one example, native oaks support 537 species of caterpillar, as opposed to a Japanese elm (Zelkova serrata), which supports none. This is because most insects are specialists able to digest the foliage of only a very limited number of plants (Monarch butterflies, whose caterpillars eat only Milkweed (Asclepias) plants, are a well-known example.)

You may like the idea of fewer insects, but fewer insects means fewer birds, amphibians, and many other animals. Without insects, the food chain collapses. And in fact the number of birds has declined by half over the last forty years.

But should gardeners be expected to take on these dire problems? Doesn’t this approach detract from gardening as a means of relaxation, of simply taking pleasure in the beauty of plants? Also, can gardeners even make a difference?

Tallamy makes a pretty good argument that gardeners could help mitigate the loss of natural habitat if they wanted to. In the USA there are 40 million acres of lawn, an area about six times the size of the State of New Jersey. It would be significant if even a fraction of that lawn were converted to native plant gardens.

But let’s be honest. The real purpose of a garden is to make the gardener happy. If a gardener can’t be happy without tulips, or lilacs, or some other exotic plant, he or she should not be asked to go without (leaving aside the issue of invasives). Native plant advocates will win few converts if they insist on purity. And some exotic plants have wildlife value, for example by providing nectar for pollinators – though not forage for caterpillars.

In my own garden, I’d guess that about 2/3 of the species are native to the region, but these are mixed with exotics that I love.

Even so, there are a large number of beautiful and underused native plants capable of giving most gardeners a great deal of pleasure. And a garden full of insects and birds is a more lively, interesting, and enjoyable place.

Tallamy has written a new book with Rick Darke called “The Living Landscape: Gardening for Beauty and Biodiversity in the Home Garden.” The idea is that we don’t have to sacrifice pleasure while gardening with the environment in mind. I read and was much influenced by Tallamy’s last book. I’m looking forward to reading “The Living Landscape”.

So, to answer my own question – hobby or crusade? I’d say the two are not mutually exclusive.