The Atlanta Journal-Constitution
Your yard needs a smarter fall cleanup
Leaving some leaves is best for insects and, therefore, birds.
In the fall, it used to be you cleaned up every last leaf like mad. Itwas considered good garden sanitation. But nowwe know otherwise: That’s bad for the environment, killing beneficial insects that love all the leaf litter, which keeps them warm during the winter, and interrupting the food web.
Ifwe arm ourselves with power tools and aim to skip no section of the garden and leave no debris behind, we risk making a place that’s too tidy for the good of its inhabitants. Part of the environmental benefit of making the landscape in the first place could be erased. Except in the vegetable beds, where pest and disease pressures call for a more forceful hand — orwhere the remains of a sickly ornamental plantmay need teasing out here and there — when it comes to cleanup, less is often more effective.
So howdo you make a responsible plan that acknowledges both ecology and your horticultural goals? Maybe it’s better to think of fall garden cleanup as an editing job — not some wholesale, wall- to- wall regimen like vacuuming the living room.
Becca Rodomsky- Bish, of the Cornell Lab of Ornithology, and
Margaret McGrath, a Cornell plant pathologist ( both serious home gardeners beyond their day jobs), shared advice about how to proceed.
The case for a messier cleanup
Within or below the leaf litter that accumulates in the autumn, somuch unseen life exists. Given the chance, it will weather the offseason there.
“If you clean up every leaf pile in the landscape, you’re not only removing or destroying overwintering insects,” said RodomskyBish, the projectmanager for the annual citizen- science project Great Backyard Bird Count and a
passionate habitat- style backyard gardener. “You're also removinginsulationforinsects burrowed in the ground that rely on the leaf litter to survive harsh winter temperatures — like so many species of ground- nesting bees.”
Instead, she suggested, “Let's be a little bit messier.”
Messier, because the litter is critical habitat for various insectsandother anthropods, like bumblebees that provide pollination services. It offers pupation sites for caterpillars of many moth species that birds rely on to feed their young. Detritivores— likemillipedesthatrecycleplantdebris — shelter beneath it for the duration, as do some spiders that contribute extensive pest control to our environments.
Whenwemowover, shred or vacuum up leaves, or rake them away fromthe tree they fell from, we diminish the potential good that the leaves and their various inhabitants — all essential players in the food web — can do.
Fadedplantsleftstandingall winter can play a critical role, too. They may contain seed or fruit, or offer hiding places for spending the offseason or reproducing, asthepithystems of goldenrod, blackberry and elderberry ( favored by some masonandcarpenterbees) do.
This year, in particular, it's urgent, Rodomsky- Bish said, as droughts, wildfires and other climate- related events are believed to have driven migratory birds off course, beforetheyhadtimetoreplenish their fat stores, and even to their deaths.
Identify where things can ( and can’t) remain looser
Nature's example— letting everything lie where it falls, orwhere the wind blows it— is the inspiration, but it may not prove feasible for every square foot of the garden.
Whilemanygardenershave reduced mowed turf in the name of biodiversity, most still have some lawn. Allowing leaves to mat it down all winter risks damaging the grass. Either mow over the leaves ( if there's just a thin layer), returning their organic matter to the soil, or rake and move them to the garden's perimeter or to vegetable beds where they can serve as mulch.
Youmay want to be tidiest along the frontwalkway and other high- trafficspotswhere slick leaf buildup isn't practical or looks too messy.
Other little nods to horticulture: In bedswhere early blooming minor bulbs like winteraconite( Eranthis), crocus or snowdrops might not be able to push up through heavyleaves, rakethosespots now; in the spring, youwon't be able to do any raking until after the bulbs flower. And leave little pockets of open soil beneath the spotswhere you hope biennials and selfsowing annuals will grow; mulch will stifle their success.
Aroundornamental plants with a reputation for harboring diseases that can survive in fallen debris — think peonies, rosesor fruit trees showing signs of trouble — move spore- filled material away from the immediate area.
Oneworry voicedbysome gardeners, Rodomsky- Bish said, is that less scrupulous cleanup creates a habitat for ticks, creatures of the leaf litter. So here's a compromise: Don'tcartawaybaggedleaves; instead, move them away from areas near the house thatyoufrequentmost. Establish looser outer spaces that can accommodate leaf litter, a small brush pile and a gentleroverallmanagementstyle.
In the vegetable garden, use a firm hand
Knowyourenemy, advised McGrath, anassociate professor at Cornell's Long Island Horticultural Research and
Extension Center, in Riverhead, New York. That's the first tactical step toward vegetablegarden health.
When she talks to gardeners about disease management, she stresses the importance of removing diseased crop debris when the disease is caused by a pathogen that can survive winter in it. Not all can.
“Iamespeciallyconcerned about fungal tomato pathogens such as anthracnose, Septoria leaf spot or early blight surviving,” McGrath said, “along with various bacterial diseases. So that debris goes out to themunicipal compost with other yard wastemyhusbandandIdon't want to compost or chip.”
Although she has the ability to distinguish one pathogen from another ( if you don't, her webpage for gardeners can help), McGrath's practice in herownvegetable plot is a thorough cleanup. “Personally, I like a clean vegetable garden, so I remove everything in fall,” she said. “By the next season, youwill want a clean planting area anyway, unlike in your ornamental beds.”
Best practice: Remove diseased or fallen foliage as it occurs throughout the season — and also any tomato, eggplant or pepper fruit showing signs of anthracnose fruit rot.
“Those fruits, or affected tissue removed from a salvageableone, reallyshouldn't go in the compost unless a gardener knows they have a good and long compost process,” she said.
In some cases — with certain bacterial speck, spot or canker of tomatoes, for instance — pathogens can survive the winter on stakes and cages.
“Hose them off to remove debris and soil, then disinfect with a bleach- andwater solution of 1: 9 dilution,” McGrath said. The gear needs to soak in disinfectant for 10 to 30 minutes.