Each fall many gardeners cut down every plant stalk, rake up every leaf and generally make things as tidy outside the house as inside. It seems firmly rooted in our DNA, this autumnal urge to erase all signs of our warm-season garden beds.

This makes gardeners feel virtuous, but all the bees, butterflies, birds and other creatures who relished our plantings throughout the warm months are bereft. They're left with diminished food to eat and fewer places to shelter, just when they need it most.

I'm adding my voice to those who advocate for a change in our garden maintenance schedules, to a more laissez-faire approach in the fall. Let's start thinking of our gardens as four-season landscapes. This means no garden cleanup of healthy plants until the spring, beginning no sooner than late March each year.

There are many good reasons to make this change, one being that our gardens are alive in all seasons of the year, and winter need not be an exception. Think of all the plants in your landscape, working hard to flourish and then go to seed to produce the next generation. Summer's flowers shrivel into seed heads that feed goldfinches, chickadees, nuthatches, downy woodpeckers and sparrows in autumn and winter. Plant stalks and grasses make for a pleasing sight in winter, too, adding color and structure to the landscape (as opposed to an unbroken sheet of snow). Those same stalks and grasses provide mini-havens for hibernating bees and butterflies, as well.

Do minimal maintenance in the fall and you may increase the diversity of your avian visitors: As the Cornell Lab of Ornithology's Yard Map site states, "The average yard can easily attract at least 50 kinds of beautiful, interesting birds with the right planning."

A winter's feast

A single bergamot (monarda fistulosa) head holds between 80 and 110 energy-packed seeds for backyard birds and mammals (I know because I counted them). Each oxeye sunflower (heliopsis helianthoides) is now a dried seed head with an average of 65 seeds. Other plants, like goldenrod (solidago), asters (asteraceae), coneflowers (echinacea) and black-eyed Susan (rudbeckia) produce abundant seeds relished by backyard creatures.

Even plants valued more for their foliage, like hostas, are seed producers: I once watched a cardinal in autumn flutter like a hummingbird in front of a Frances Williams hosta stalk as he plucked out its big black seeds.

There's growing awareness of the value of insects to our gardens, and it's time we returned the favor with a round-the-calendar outlook. For example, many kinds of native bees, such as bumblebees, mason bees and leafcutter bees, overwinter in our gardens. Some are hiding under piles of leaves, while others nest in plant stem cavities or burrow into the ground, a good argument for leaving well enough alone.

Leave the leaves

We all love to see butterflies fluttering over summer gardens, and many of these benefit from the not-too-neat approach. Mourning cloaks, question marks and Eastern comma butterflies overwinter as adults in sheltering piles of leaf litter or natural cavities. Leaves also hold the chrysalises of swallowtail and sulfur butterflies, and the caterpillars of the handsome red-spotted purple and viceroy butterflies wrap themselves in a leaf to sleep away the winter.

If you've come around to the idea of beneficial insects, you know how they help maintain the natural balance in our garden beds by controlling harmful insects. You'll want to encourage assassin bugs, lacewings, wolf spiders, ground beetles and ladybugs, since they help control garden pests, but they need layers of leaf litter to survive the cold.

"Leave your garden up" is the new mantra for gardeners who take the year-round perspective. There's time enough in spring to do the cutting and clearing that makes way for spring and summer's burst of blooms.

There's even a movement for those of us who let sleeping stalks stand — we can sign up online to Pledge to be a Messy Gardener (https://bit.ly/2C5rqRl). This excellent site clearly makes the case for leaving gardens well enough alone.

Gardens bring so much pleasure to humans, but they also are vital to the survival of birds, bees and butterflies. And in fact, the messier the garden in winter, the more wildlife we'll see come spring and summer.

St. Paul resident Val Cunningham, who volunteers with the St. Paul Audubon Society and writes about nature for local, regional and national newspapers and magazines, can be reached at valwrites@comcast.net.

'Messy' is a good thing

Leave plant stalks standing over the winter (their seeds nourish birds).

Have spaces where leaves can pile up (as shelter for insects).

Allow bunch grasses to go to seed (as food and shelter).

Leave spaces uncovered by mulch (so native bees can burrow in).

Build a brush pile (to shelter birds, bumblebees and other creatures).

Delay garden cleanup until after several 50-degree days in spring (to allow pollinators sleeping in plant stems to awaken and move away).