Let's take a look at the garden tasks most commonly considered "must-dos" and separate those that are up for discussion from those we just have to buckle down and do.
Our most dreaded fall chore may not be as necessary as you think. For years, northern gardeners -- driven by an urge to clean, a Midwestern work ethic or a desire to control nature -- have felt compelled to tidy up before winter by pulling out annuals and vegetables and cutting perennials to the ground. But is a clear-cut garden a better garden?
Why do it: A big fall cleanup cuts down on the work you'll have to do next spring to get your garden ready. It also can cut down on weeds.
Skip it if: You have healthy plants. "We edit in the fall," said Arla Carmichiel, head gardener at Noerenberg Gardens in Orono. "We cut down things that look crummy, otherwise we leave them standing."
Many experts and everyday gardeners argue that there's no need to remove frost-zapped perennials. In fact, leaving plants in place traps insulating snow, which can help plants survive the winter. Plenty of perennials (such as coneflowers, sedums and ornamental grasses) can stand up to the weather, adding what we've come to call "winter interest." And some folks say letting the garden decline naturally is one way to extend fall.
"It's hard for me to cut the season off like that," said Paige Pelini, co-owner of Mother Earth Gardens in Minneapolis. "I do pull weeds in the fall. I do empty my containers. But I let the perennials do their thing. I like to see them poking through the snow."
Bottom line: "Remove any diseased plants or plants laden with insects," recommends Deb Brown, a local garden writer and former extension horticulturist with the University of Minnesota. Even healthy annuals and some vegetables can be left in place. But Brown draws the line at disease-prone tomatoes. "Tomato plants and any fallen fruit really ought to go, too. By the end of the season, most tomato plants have at least some diseased leaves. And rotten fruit attracts wasps and other insects."
Beyond that, well, "it's a matter of personal preference," said Carmichiel.Just do it
Most of us tend to roll up our hoses and turn off the sprinkling systems when jacket weather comes. But after a dry summer like this one, plants need to be well watered as they head into winter.
Why do it: We're in our second straight summer of drought in the Twin Cities. Some lawns, perennials, shrubs and even mature trees are showing signs of stress. "We're seeing trees dying this fall because people just don't realize mature trees need water," said John Lloyd, director of research and science for Rainbow Treecare.
Skip it if: We start to get regular, abundant rainfall.
Bottom line: Continue to water right up until the ground starts to freeze. And don't overlook the trees. Lloyd recommends wrapping a soaker hose around each tree, about 3 feet out from the base and letting it slowly trickle overnight. Mulching around the base of trees helps conserve water. (For more on watering and mulching trees, go to www. forestry.umn.edu/extension/.)Debatable
Contrary to popular belief, winter mulch doesn't keep the cold out. It's job is to keep the soil evenly cold through winter, avoiding some of the freeze-thaw cycles that can damage plants. It also helps hold soil moisture through winter, keeping shallow plant roots from drying out and dying. And it can keep cold, dry air from penetrating as deeply as it would in bare soil.
Why do it: There's no doubt that insulating mulch can help plants survive winter. In the old days, when we had "real winters," we could count on snow to provide that insulation. But we've had several winters with little, late or inconsistent snowfall.
Skip it if: You don't mind losing a few plants. And lots of gardeners, even pros, don't. Carmichiel doesn't mulch the spectacular beds at Noerenberg. "If there's something I think is really special or was really tiny when we put it in, we'll mulch," she said. "But there are lots of good plants to try. If we lose something, we try something new."
Pelini agrees. "If I had a perfect life, I would mulch my gardens," she said. "But I'm a realistic gardener. Some years I mulch. Some years, I'm in a rush and I don't mulch anything but plants I know to be tender."
Bottom line: Mulch anything you planted this season, tender perennials and much-loved plants. (A tough winter with little or no snow cover can take out even Zone 4 hardy plants.) After the ground starts to freeze, spread a thick layer of mulch around perennials, bulbs, trees and shrubs. Use 4 to 6 inches of straw or marsh hay or at least 6 inches of leaves. "More is better for leaves," said Brown. "They tend to pack down." Just be sure to wait until the ground starts to freeze, usually in mid- to late November in the Twin Cities.Just do it
Raking is about more than just being tidy or giving yourself and excuse to be outside on a beautiful fall day. It helps keep your lawn healthy.
Why do it: A thick layer of leaves can mat down, reduce air circulation and even cause grass to die back.
Skip it if: You have only a thin layer of leaves. Just run the mower over the lawn a couple of times to chop up leaves. The chopped leaves will decompose and filter into the soil, adding organic matter.
Bottom line: Leaves make a good winter mulch and the price can't be beat. So if you have lots of leaves, rake them, bag them and use them to insulate your plants.Just do it
While many other plants shut down in fall, our cool-season lawn grasses perk up. "That's when we want to see them get sufficient moisture and ample nutrients," said Bob Mugaas, University of Minnesota extension educator and turfgrass expert.
Why do it: Feeding in fall is more beneficial than feeding in spring. "In spring, the energy goes into flowering, rather than thickening up and making new rhizomes," said Mugaas. "Having healthy grass in the fall makes for good winter survival and a good start in the spring."
Skip it if: Don't fertilize if your lawn is stressed by drought. Water regularly instead.
Bottom line: Continue to water. (An inch every couple weeks -- from the sky or your sprinkler -- should do.) And put down a final application of fertilizer at the end of October.Just do it
Don't stow that mower yet. A long as your grass continues to grow, you should continue to mow.
Why do it: Leaving grass too long going into winter can cause snow mold, which can damage or kill grass plants.
Skip it if: Your grass is so drought-stressed that it is no longer actively growing.
Bottom line: It's best to leave grass about 2 to 2 1/2 inches long going into winter.
Connie Nelson • 612-673-7087