From Chris and Jim Trevis

Stick to your USDA zone. Unlike some gardeners who push the zone and cross their fingers, Chris buys only plants that are certified hardy for Zone 4. With a large garden like hers, it's important to concentrate on plants most likely to reward the effort. "I can't baby-sit my plants. Life's too short," she said.

Rely on old reliables. Chris recommends identifying several hardy perennials that grow well in your conditions, then making them the foundation of your garden. "I stick with my workhorses -- things that come back faithfully every year," she said. "Make them 80 percent of your garden. Then add something unique" for the remaining 20 percent.

Plant for all seasons. If you love a particular flower but it blooms only briefly, it doesn't add much to your garden's long-term beauty. "Think about plants that give you the most bang for the buck -- that look good in spring, summer and fall," Chris said. She likes lady's mantle, astilbe, cranesbill, phlox and black-eyed Susan, and is cutting back on fleeting flowers. "I'm having second thoughts about iris -- they bloom for a week."

Plant for comfort. The Trevises have learned to avoid "thorny stuff, such as roses and barberry bushes," Jim said. "You don't want your plants to attack you or make you depressed," Chris said.

Double duty. When choosing plants, Chris looks for those that serve two purposes: provide beauty and benefit wildlife in some way. "Like dogwoods," she said. "The birds love them. And they're a nice color, with nice twigs."

Three strikes and you're out. Moving a plant, to find the optimum spot, is good. But not repeatedly. If a plant doesn't thrive in one spot, Chris tries another. But three tries is her maximum, with a few rare exceptions. After that, if a plant still isn't doing well, she figures it's not a good fit for her garden and moves on to something else.