Eugene Weekly : Gardening : 7.16.2009


Back to Nature
Converting gardens to native plants over time
by Rachel Foster

This past Mother’s Day, at least 500 people attended Eugene’s first native plant garden tour. Organized by the Native Gardening Awareness Program (NGAP, a committee of the Emerald Chapter Native Plant Society of Oregon), the tour gave native plant enthusiasts and curious gardeners an opportunity to visit four public and eight private gardens where native plants play an important role. The private gardens varied greatly in age, setting, style and strategy, making for an interesting tour. 

Aryana Ferguson and Bart Johnson’s yard adjoining Tugman Park is about 80 percent native and relatively mature: The formative “big push” came in 2003. Now salamanders make a home here, sapsuckers nest and chickadees and flickers squabble over a snag. Hummingbirds abound, and a scarce hairstreak butterfly has laid eggs on the checker mallow. The day of the tour, the sunny front yard was ablaze with a pink froth of annual rosy plectritis intermingled with native buttercups, all busy with insect pollinators. I returned at the end of June to talk with the owners about their garden and the makeover experience, and was greeted by a whole new crop of flowers.  

These people are pros. Ferguson has worked in resource management for 19 years and currently owns Madrona Consulting, working as project manager for a variety of restoration projects. Johnson, a professor at the UO, is an ecologist and landscape architect who works to merge ecological function with form and beauty. We talked on a deck overlooking the back yard, where they’ve kept a number of mature non-native plants — trees, mostly, and a few shrubs, which contribute both shade and structure. 

When I toured this garden in May, I was struck by its use of sedges and grasses, so prevalent in nature but often omitted from native gardens. A central feature of the back yard is a swale designed to take runoff from the roof. Sedges flourish here. Slough sedge (Carex obnupta) seems to be the most satisfactory — it likes semi-shade and stands up well. Uphill from the slough, in dappled shade, is a soft, bluish green lawn consisting mostly of Roemer’s fescue. “We mow every two weeks to keep the fescue from shading itself out,” said Johnson, “and we have to weed out exotic forbs and grasses.” Still, he’s surprised how little work it’s been. 

As we toured the garden, Ferguson indicated a taller grass: “California fescue is a good bunch grass, especially in winter, when it looks really pretty,” she said. Johnson commented on big chunks of logs scattered here and there among the plantings. “Put out some large wood out for salamanders and snakes. They love it.” We passed a sizable patch of camas (“it seeded in here on its own”) prompting the comment that camas is one of the easier plants to grow. Once it dies down, you can mulch over it. Oregon iris is another winner. It is easy to weed around the clumps and, unlike camas, it stays green all summer.  

Although their own garden was a radical makeover, Ferguson and Johnson now advise people to start small. “Don’t try to convert everything to natives all at once,” Johnson suggested. “Start from less diversity and add more as you can handle it,” he said, “and plant clumping things you can mulch around,” he emphasizes. “The easiest native garden to manage is one of shrubs, sedges and ferns, in shade.” You can’t mulch prairie because you want things to self sow, so weeds are a bigger problem. Establish patches of easy perennials first, and mulch to reduce weeding. Fill in with annuals later. 

In their sunny front yard, the couple removed weed cloth, bark mulch and the standard issue landscape shrubs, then sheet mulched with cardboard and two inches of mycorrhizal soil from Lane Forest Products to get a fresh start. Now a mix of prairie species with some from bright woodland, this area is still a work in progress. “We began by throwing out a lot of seed to create high diversity mixes of species,” said Ferguson, “and it didn’t work. We redid it with an effort at an aesthetic people are more used to.” Grasses are allowed only in clumps; perennial forbs are corralled in well-defined groups.  “Each year we bring a little more order to it,” she said.

NGAP and The Native Plant Society of Oregon are a tremendous resource for native plant gardeners. Visit for a list of native plant nurseries and informative booklets and checklists. 

Rachel Foster of Eugene is a writer and garden consultant. She can be reached at