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Garden and landscaping books are a dime a dozen, but critics took special notice of Thomas Rainer's 2015 book "Planting in a Post-Wild World." The book, which he co-wrote with Claudia West, was called groundbreaking, masterful and "as practical as it is poetic."

Rainer, a landscape architect who has designed plantings for the U.S. Capitol grounds and the Rev. Martin Luther King Jr. Memorial, recently spoke at the Minnesota Landscape Arboretum. Some listeners were moved almost to tears by his talk on the importance of creating ecologically responsible gardens that bring the wild back into an increasingly urban world.

Yet Rainer isn't a pedant. There's room for fun in his landscapes, and his own yard in Virginia has old-fashioned annuals and a patch of lawn where he can toss a ball with his son. Our gardens should bring us pleasure, he says, and if we look to nature for guidance, we will have less work and enjoy our yards more.

Rainer, who blogs at ­thomasrainer.com, took a few minutes to talk about his work, the urgency of urban gardening and Americans' obsession with mulch:

Q: You say wildness matters more now. Why?

A: Half of the world's population lives in cities. We're urbanizing at a pace unprecedented in human history. That increases desire for experiences of the wild — moments of sunset, moments of seeing grasses backlit, watching a caterpillar emerge from a chrysalis. All of these things are things our grandparents experienced on a daily basis. Now these are things I show my 6-year-old son on ­YouTube.

As we urbanize, having our memory of the wild tickled will be more pleasurable. I think this is why the High Line in Manhattan (an abandoned elevated rail line that is now a park with prairie plants) is the most visited site in all of New York City. What does it say that what urban dwellers want to see more than anything else is the imitation of a meadow?

Q: Yet you don't argue for using only native plants in landscapes.

A: Conservation and restoration don't make any sense on the highly disturbed urban sites I deal with every day. There's pressure for them to be beautiful; there's pressure for them to be ecologically functional, and there's pressure to look good in four seasons. … To combat environmental problems, we need to start looking at the places around us — the parking-lot islands, the drainage ditches, the sides of the road, the backyards — as places where nature can be.

Nature is not apart from us, nature is us. And it means working with some of the invasives we have that we won't be able to totally eradicate. The goal is to get as much native biodiversity as possible, but we have to make compromises when resources aren't endless.

Q: What does that mean for gardeners?

A: There is a huge opportunity in looking at gardens and finding places to add more native biodiversity, and that's possible to do without having to rip out your foundation plants, without having to abolish your lawn.

We have this particular American habit of adding 2 to 4 inches of mulch in our yards, which you don't see in Europe or Asia. When you see their gardens, they are chock full of plants. What you see in our gardens are plants swimming in a sea of mulch.

So for us the big shift is to think of plants not as individual objects but as dynamic systems. Gardeners can look at their existing plantings, find the places where there is bare mulch, and add plants. Because if you look at how plants grow in the wild, plants cover soil. Plants want to be green mulch. As you replace mulch with native groundcovers, you can include lots of flowering plants. The labor goes way, way down, and biodiversity goes up. And I think the look is better, too.

Q: You speak of going from maintenance to management.

A: When you think about plants as individual objects, maintenance needs to be individualized. Certain plants need to be staked, need to be deadheaded; some need more water, others need less. When you start planting as a community, you do everything at once.

Plants are social creatures. Most of a plant's shape and behavior is a reaction to growing among other plants. Butterfly weed is exactly the same height as surrounding grasses; it helps the pollinators find it. The fact that it has almost no leaves is a way for it to move through that matrix. It has a taproot to drill through the fibrous roots of grasses.

We understand a plant best when we understand how it has evolved to grow among its companions.

Q: Yet native plants are still underused in landscapes.

A: We think the aesthetics of natives have not been fully tapped. The best North American native plant gardens are in Europe. And that's because the Dutch and the Germans and the English are geeked out on our native flora, not because they're good for bees and pollinators but because they think our flora is some of the most gorgeous flora anywhere in the world.

A state like Minnesota probably has five times the native plant diversity of the whole British Isles. We're spoiled for choice. But the nursery trade does not propagate enough of the right plants, and we're not understanding how to combine them for the best aesthetic effect.

We believe in natives … but you have to think about plant performance and maximizing bloom. A well-behaved exotic may increase ornamental value and can make plantings more acceptable.

Q: Is our idea of what makes a garden too rigid?

A: I think so. If you look at the American suburban yard, they're not landscapes of pleasure, they're landscapes of labor. The pruning, the lawns — we do these things because we want things that are low-maintenance and we don't want to tick off our neighbors. We don't typically have gardens we love.

But for me, as a gardener, what I want to communicate is the pleasure. The most pleasurable part of the garden is to go out and watch not only seasonal change, but change day by day. Watch the pollinators, watch the plants. To watch life day by day.

Q: What about gardeners who love peonies or roses?

A: Keep those beloved garden plants. But intermingle them with beautiful salvias and low blue sedges or put them in combinations so their ornamental qualities are amplified. Layering compatible plants is really useful, just as we do in container arrangements.

The thing we want to do more than anything else is to encourage people to get pleasure out of their plantings. It is not about plants being good or bad. We're trying to talk about how to get more tools based on the way plants grow. It's a tool for lower maintenance, more biodiversity, more pleasure and squeezing more color out of small spaces.

Mary Jane Smetanka is a Minneapolis freelance writer, a Hennepin County master gardener and a tree care adviser.