Douglas Tallamy might just turn your idea of gardening on its ear. That's because Tallamy judges plants not by how they look, but by how they function in the environment.

Tallamy, a professor of entomology and wildlife ecology at the University of Delaware, has studied the link between native plants and native wildlife. What he's learned is that the loss of native plants results in loss of native insects, which provide food for birds and other animals. In his book, "Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens," he argues that what we grow in our own back yards makes a difference in our world. He'll bring that argument to town next week when he speaks at the Wild Ones conference.

Q You have a unique take on gardens, don't you?

A Most gardeners look at plants as ornaments. I look at what they do. I just want people to realize their gardens have a function. We've designed our landscapes only for aesthetics. We put in pretty plants and if we see an insect, we kill it. That's an extremely artificial environment. We're not looking at our gardens as living, changing ecosystems.

Q What's wrong with looking to plants for pretty?

A There's nothing wrong with it, unless everybody does it. It's imperative that we change the way we treat our landscapes. We have a serious extinction crisis on our hands. Ninety percent of all birds rear their young on insects. If there are no insects, then there will be no birds.

Q Does one yard really make a difference?

A We have this idea that nature is happy somewhere else. But we've taken 95 percent of nature. Fifty-four percent is in cities, 41 percent goes to farms. If nature is going to survive, it's going to be in our yards and parks.

Q You paint a dire picture. Are we that bad off?

A Well, humans need nature. We need a biodiverse ecosystem to live. But we can learn to share. That's my main point: We can coax nature back into our yards -- for our own good.

Q Don't we have nature in our yards already?

A Well, a lawn is a pretty barren place, considering that many of them used to be forests. We've put some of the trees back, but they usually aren't the ones that were there before. Plants provide food and shelter for insects and birds and other wildlife. But when you use plants that are from outside of our food web, they don't participate.

Q Can you give us an example?

A Sure. If you have a typical yard you have a lot of grass and a couple of trees, say they're ginkos. You may have a few birds that fly by, but your yard isn't going to sustain those birds. Ginkos evolved in China, so if you plant one over here, the insects, birds and other animals in your yard don't recognize it. It could just as well be a plastic tree.

Q You don't seem to be a fan of introduced species. You call non-natives "aliens."

A I'm not against them, but from an ecological point of view, aliens are a bad thing. In the U.S., 85 percent of woody invasive plants are escapees from our gardens. And we've got more than 3,400 species of invasive plants.

Q So, is going native the answer?

A It's not just about natives. It's about trying to get more and more different kinds of plants -- true diversity -- even in small spaces.

Woody plants have a much more powerful impact on diversity than perennials because they support a lot more insects, which in turn, support a lot more birds. If you can grow some native woodies and then plant a few alien perennials, you'd be meeting me halfway.

Q Have native plants gotten a bad rap?

A Natives haven't been given a chance. Big growers are out there pushing cultivars, not natives. There's not big money in them, so you don't see splashy ad campaigns promoting natives.

Q You have some radical ideas. Have you gotten push-back from gardeners?

A No. Well, not yet anyway. What I hear people saying is, "Oh, I would never have thought of it that way." I'm not a garden insider, I'm an entomologist, so I can offer a different perspective. If I've gotten a few people to think about the function of their plants, then I've been successful.

Connie Nelson • 612-6763-7087