Every year about this time I used to faithfully practice "fall cleanup." I'd meticulously remove annual flowers and clean up perennial beds, disposing of all twigs, leaves, and dead vegetation. But I soon realized that my overzealous cleaning left less of the natural food and shelter that wildlife needs for the winter. In the fall, some things are just better left undone. Now majestic sunflowers dangle their giant seed-laden heads in my Oregon garden, and the last clusters of autumn grapes remain unharvested. The lawn goes unmowed, and a few tall grasses linger in a corner by a brush pile. As the annuals near the end of their colorful show, I leave the spent flowers on the stalk. Instead of clearing things out of my garden, I add things: trees and shrubs that offer winter berries for birds, mulch and cover crops that shelter amphibians and nourish soil microorganisms, bird feeders for hungry resident songbirds. After all, why provide wildlife habitat only in the spring and summer? By making the following changes in your autumn routine, you can turn your garden into a welcoming place that provides refuge even in winter.

Don't Pick the Flowers
If you're like me, you remove dead flowers during the summer to keep the plants blooming longer. However, once fall has arrived, it's best to let the flowers mature and produce seeds. The deep-red seedheads of some sedums, for instance, not only add color and beauty to the late-fall garden but also food for seed-eating birds like sparrows, grosbeaks, and siskins. The large cone at the center of a purple coneflower turns black as its seeds mature, serving as winter nourishment for goldfinches.

Leave dead vines, too, and the dead stalks of hardy perennial flowers. In my winter yard, a cushion of dry blackberry vines offers cover for a host of birds and even rabbits. Come spring, our two dozen birdhouses attract a large flock of swallows to the garden. I watch as they collect last season's remaining vines and other garden material to make their nests.

 Fall is the time to think of food for next year. Dividing and replanting overcrowded perennials will bring more flowers for you to enjoy in the summer -- and more nectar and pollen for creatures like ladybugs, butterflies, honeybees, and hummingbirds.

Pile it On
If you hate to rake, you can let the leaves fall where they may with a good conscience: They'll form an insulating mat that keeps the soil warmer, feeds beneficial microorganisms, and protects your garden from the pounding rains that winter brings in places like the Pacific Northwest. But if rake you must, go right ahead. Just don't compost all those little piles; leave a few for hibernating lizards, frogs, and toads. They need only "a place that stays at about 35 degrees Fahrenheit," according to Jeff Boundy, a herpetologist with the Louisiana Department of Wildlife and Fisheries. "Even in the South," he says, "reptiles will seek winter refuge in a pile of rocks." In most regions of the country, adult ladybugs overwinter under piles of garden debris and in other protected places, ready to emerge at the first sign of spring. Snakes hide out under boards or in compost piles. In the North, you can insulate a pile of rocks with an armload of leaves to provide a nice winter habitat. 

Reptiles and amphibians also hide in the nooks and crannies of loosely stacked brush piles, which you can make with fallen branches. Start with a two-foot layer of thick branches, and add a few more feet of thinner branches. In colder climates, top it off with a layer of evergreen branches. Birds and hibernating butterflies will duck in and find winter shelter there. Bumblebees, carpenter bees, digger bees, and other bees that don't live in colonies might nest in holes in the wood or in between the branches. 

Piles of firewood work equally well for sheltering wildlife. The ideal log pile is five feet high and six feet long, with logs placed crosswise to create as many open spaces as possible -- and to keep the wood from rotting. When I was growing up in southern California, we always had a huge log pile under an old orange tree. It sheltered plenty of lizards through the mild winter. Now, in the Pacific Northwest, my husband and I have a log pile that is home to several tree frogs croaking their greetings on a sunny winter's day.

Dead or dying trees also have a place in the wildlife landscape; leave them be unless they threaten people or property. Hollow trees give bluebirds, woodpeckers, owls, and other cavity-nesting birds a place to roost at night. The tree's bark usually hides a gold mine of tunneling insects and grubs that can feed hungry sapsuckers, nuthatches, and brown creepers. And dead trees often host beneficial fungi, such as edible mushrooms, and lichens, an important source of food and nesting material for many birds.

Feed the Soil
This time of year it's best to leave weeds and grass alone; they provide instant shelter for butterflies, beetles, and ground-feeding birds. Take advantage of the growing time that's left to reseed bare areas with grass. 

Protect the roots of trees and perennials from heavy freezes with a thick layer of mulch around the base. Mulches of shredded leaves, garden debris, grass clippings, and compost will also provide food for earthworms, microbes, and other beneficial creatures that live in the soil. "One teaspoon of healthy garden soil is alive with more than 600 million bacteria, protozoa, fungi, and beneficial nematodes," points out microbiologist Elaine Ingham, a soil ecologist at Oregon State University. Even woody organic material such as straw, leaves, and bark chips will provide food for carbon-eating fungi and the microorganisms that break down the material, improving soil structure and delivering valuable nutrients to plants. "Since woody material tends to tie up excess nitrogen in the soil, the best time to provide fungal food is in the fall and winter, when plants have stopped growing rapidly," says Ingham. 

Plan to Plant
The more plants you have, the more wildlife you'll have, especially when it comes to birds. You can attract a lot of avian species with a mix of vines, shrubs, and trees of different heights -- a complete package of food, shelter, and nesting sites. Fall is a great time for planting. Create a hedgerow with groups of trees and shrubs, using three to five of a kind. Try plants like witch hazel, holly, mountain ash, trailing blackberry, viburnum, or juniper. These bird-friendly plants and trees provide shelter for most species of birds, as well as food for berry eaters such as thrushes, robins, and waxwings. 

You can also plant cover crops, a living mulch of legumes or other plants that return nitrogen, phosphorus, potassium, and essential trace minerals to the soil. Above ground, the green leafy matter protects the soil from erosion and creates an inviting environment for beneficial insects. (Most insect pests prefer garden crops or flowers.) Come spring, turn the plants under the soil to generate the most nitrogen and to add organic matter, which improves soil texture and feeds beneficial bacteria, fungi, and protozoa. A cover crop such as clover or vetch can be grown in as little as 16 square feet. 

Help the Birds and the Bees
Winter can take its toll on resident birds, which may lose 7 to 15 percent of their body weight just trying to keep warm on extremely cold nights. As the days become shorter, there's less time to forage. As insects hibernate and the growing season comes to an end, there's less food. Bird feeders can help provide the energy birds need to survive through the winter. You can attract a large variety of birds with just a few well-placed feeders. Put them in a sheltered area that's easily accessible to you but within 5 or 10 feet of trees or shrubs, so the birds have a place to hide from neighborhood cats and other predators. 

A tray or platform feeder, one to three feet high, might be visited by ground-feeding birds such as juncos, sparrows, towhees, and mourning doves. Hung from a tree or mounted on a pole, a hopper feeder (with perches, or "hoppers," on the sides) will entice grosbeaks, cardinals, and jays. Suspended tube feeders filled with niger (thistle) seeds are favored by goldfinches, siskins, and redpolls. It's best to keep feeders filled with only one type of seed, to avoid waste. Many of the seeds found in birdseed mixes are not especially popular, and visiting birds will often drop or kick out seeds just to get to their favorite kind. That favorite, according to the Cornell Laboratory of Ornithology, is the black-oil sunflower seed, which is preferred by the widest variety of bird species, from chickadees to cardinals. White millet is popular with ground-feeding birds; scatter it on the ground or in a low platform feeder.

Your wintertime bird-feeding station might also include suet for woodpeckers, titmice, nuthatches, and chickadees. In California and parts of the South, fill hummingbird feeders with one part sugar to four parts water. Even fruit -- bananas, apples, and water-soaked raisins and dates -- can help feed a few species, such as thrushes, robins, waxwings, bluebirds, and mockingbirds. Oranges top the list for orioles. To make a fruit feeder, drive several long nails through a board and attach it to a feeding platform. Then stick the fruit on the nails like shish kebab. Ready-made fruit feeders are also available at many bird stores. 

Birdhouses can be useful during winter as well as spring; chickadees, nuthatches, and bluebirds may occasionally take cover there. And try setting out houses for mason bees, leaf-cutter bees, and sweat bees. Available at full-service gardening centers, these "houses" are weather-resistant wood blocks with predrilled holes of a specific size. If you grow any fruit, you'll want to increase your own population of mason bees, which are very effective fruit pollinators. 

Whether the wildlife you prefer flies the skies, roams the ground, or hides deep within the soil, now is the time to set out the winter welcome mat. Around my house, fall cleanup is no longer a chore but a ritual I look forward to. As I rake the last of autumn's leaves into a pile, a dark-eyed junco looks on from the top of the garden gate, patiently waiting for his next meal of bugs to be exposed. 

Kris Wetherbee, who writes for such magazines as Organic Gardening and Country Journal, has been welcoming wildlife to her yard for the past 10 years.

Sow six to eight weeks before the first hard frost, then turn into the soil the following spring. Some cover crops will die back in winter, leaving a mulch of stubble to till in.