Reasons NOT to clean up the garden this fall

by Jessica Walliser: Twenty-some years ago, fresh out of college with a horticulture degree in-hand, I started teaching adult education classes at a local botanic garden. For many years, I taught a class called Preparing Your Garden for the Winter. I would show slides (remember those?) of how well-kept gardens should look in January. In the images, every plant was cut to the nub, except for the ornamental grasses and butterfly bushes, and the whole garden was snug under a thick layer of mushroom soil mulch. The roses were neatly trimmed to two feet and wrapped in a blanket of burlap, folded and stapled closed to keep them protected from freezing winds. There was nary a fallen leaf in sight; everything was raked up and hauled off.

You see, that’s how we gardeners used to roll in the early ’90s, before we knew better. Before we knew all the reasons NOT to clean up the garden. We’d cut everything down and “clean up” the garden until there was no shred of nature left behind. We’d turn the place into a tidied, controlled, and only slightly dirtier version of our living room. Everything was tucked and trimmed and in its place. Most of us weren’t interested in supporting wildlife much beyond hanging up a bird feeder, and the phrase “wildlife habitat” was only used in places like zoos and national parks.

Unfortunately, many gardeners still think of this kind of hack-it-all-down and rake-it-all-up fall clean up as good gardening, but in case you haven’t already noticed, I’m here to tell you times have changed. Preparing Your Garden for the Winter is a completely different class these days. We now understand how our yards can become havens for creatures, large and small, depending on what we plant in them and how we tend to our cultivated spaces. Thanks to books like Doug Tallamy’s Bringing Nature Home, we now know how important native plants are for insects, birds, amphibians, and even people. Our gardens play an important role in supporting wildlife and what we do in them every autumn can either enhance or inhibit that role.

To that end, I offer you these six very important reasons NOT to clean up the garden in the fall.
1. The Native Bees: Many of North America’s 3500-plus species of native bees need a place to spend the winter that’s protected from cold and predators. They may hunker down under a piece of peeling tree bark, or they may stay tucked away in the hollow stem of a bee balm plant or an ornamental grass. Some spend the winter as an egg or larvae in a burrow in the ground. All native bees are important pollinators, and when we remove every last overwintering site by cutting everything down, we’re doing ourselves no favor. We need these bees, and our gardens can provide them with much-needed winter habitat.

Related post: Supporting native bees

2. The Butterflies: While the monarch flies south to overwinter in Mexico, most other butterflies stay put and take shelter somewhere dry and safe until spring. Some butterflies, like the mourning cloak, comma, question mark, and Milbert’s tortoise shell, overwinter as adults. They nestle into rock fissures, under tree bark, or in leaf litter until the days grow longer again and spring arrives. Butterflies that overwinter in a chrysalis include the swallowtail family, the cabbage whites and the sulphurs. Many of these chrysalises can be found either hanging from dead plant stems or tucked into the soil or leaf litter. And still other butterfly species, such as the red-spotted purple, the viceroy, and the meadow fritillary, spend the winter as a caterpillar rolled into a fallen leaf or inside the seed pod of a host plant. If we cut down and clean up our gardens, we are quite possibly eliminating overwintering sites for many of these beautiful pollinators (and perhaps even eliminating the insects themselves!). Declining butterfly populations are one of the best reasons not to clean up the garden.

Related post: Plant extra dill for the swallowtail butterflies

3. The Ladybugs: North America is home to over 400 different ladybug species, many of which are not red with black polka-dots. While the introduced Asian multicolored ladybug comes into our homes for the winter and becomes quite a nuisance, none of our native ladybug species have any interest in spending the winter inside of your house. Most of them enter the insect world’s version of hibernation soon after the temperatures drop and spend the colder months tucked under a pile of leaves, nestled at the base of a plant, or hidden under a rock. Most overwinter in groups of anywhere from a few individuals to thousands of adults. Ladybugs are notorious pest eaters, each one consuming dozens of soft-bodied pest insects and insect eggs every day. Leaving the garden intact for the winter means you’ll get a jump start on controlling pests in the spring.

Related post: Lost ladybugs

4. The Birds: Insect-eating birds, like chickadees, wrens, titmice, nuthatches, pheobes, and bluebirds, are very welcome in the garden because they consume thousands of caterpillars and other pest insects as they raise their young every gardening season. Leaving the garden intact through the winter months means there will be more protein-rich insects available to them during the coldest part of the year – yet another of the great reasons not to clean up the garden! These birds are quite good at gleaning “hibernating” insects off of dead plant stems and branches, and out of leaf litter. The more insect-nurturing habitat you have, the greater the bird population will be. Your feathered friends will also appreciate feasting on the seeds and berries they can collect from intact perennial, annual, and shrub stems.

Related post: Berries for the birds

5. The Predatory Insects: Ladybugs aren’t the only predatory insects who spend the winter in an intact garden. Assassin bugs, lacewings, big-eyed bugs, minute pirate bugs, damsel bugs, ground beetles, and scores of other pest-munching predatory insects spend the winter “sleeping” in your garden as either adults, eggs, or pupae. They’re one of the best reasons not to clean up the garden in the fall because they help you control pests. To have a balanced population of these predatory insects, you have to have winter habitat; when spring arrives, they’ll be better able to keep early-emerging pests in check if they’ve spent the winter on-site, instead of over in the neighbor’s yard.

Related post: Lacewings

6. The People: If the previous five reasons aren’t enough to inspire you to hold off on cleaning up the garden, I’ll add one final reason to the list: You. There is so much beauty to be found in a winter garden. Snow resting on dried seed pods, berries clinging to bare branches, goldfinches flitting around spent sunflowers, juncos hopping beneath old goldenrod fronds, frost kissing the autumn leaves collected at the base of a plant, and ice collected on blades of ornamental grasses. At first, you might not consider yourself to be one of the reasons not to clean up the garden, but winter is a lovely time out there, if you let it be so.

Delaying your garden’s clean up until the spring is a boon for all the creatures living there. Instead of heading out to the garden with a pair of pruning shears and a rake this fall, wait until next April. By then, all the critters living there will be emerging from their long winter nap. And even if they haven’t managed to get out of bed by the time you head out to the garden, most of them will still manage to find their way out of a loosely layered compost pile before it begins to decompose.Reasons NOT to clean up the garden this fall