Image of American bumblebee2

These Animals Are Made Possible by Fallen Leaves

You can have all the native plants you want, but you won’t have nearly as many wild visitors unless you also leave the leaves

I opened the October issue of Consumer Reports with a feeling of mild dread. Every autumn, the magazine publishes an article extolling the virtues of leaf blowers, mowers, and other tools of destruction. This year was no different. A piece debating the pros and cons of vacuum functionality warned that leaf blowers might damage plants. But not to worry, the writer noted in the online version of the article: You can always switch to the vacuum mode instead! “If you have a small yard and are diligent about keeping up with leaves as they fall, or if you want to surgically suck up leaves from around bushes and flower beds, the vacuum mode on your leaf blower can save you time and effort.”

Time, effort, money—these are the shortsighted reasons often cited for deploying weapons against nature. I could list dozens of reasons why leaf blowers and vacuums are counterproductive to all three of those goals. But that would be beside the point. In an era of compounding losses, we need to focus not on saving ourselves from inconvenience but on saving lives instead.

As I watch plants go to sleep for the winter, I think of all the animals who are doing so too, especially the ones who’ve been able to make a life here because we have enough leaves to help them through every season. From the luna moth to the wood frog, many of our wild residents need the ground layers that so many of our human neighbors are intent on blowing away. Some of the species featured here were new to our habitat this year—a testament to what can happen when we adopt an ethos of minimal disturbance to the land.

The Luna Moth

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“What’s this?” my husband, Will, texted me from outside one late July night. He’d been taking out the recycling when he happened upon this luna moth perched on a hickory tree near the driveway. We’d seen these beauties before, but not yet in our own little habitat. Over the years we’ve planted and nurtured many of the luna moth’s host plants: hickories, walnuts, sumacs, sweetgums and persimmons. But just as importantly, we’ve left the leaves to fall where they may underneath those trees. Like most other moths, luna moths overwinter in a cocoon in that leafy ground layer. (Moths are also in trouble because of light pollution, so our efforts to keep outdoor lights off at night—and to close the curtains inside—are likely making a difference too.)

The Wood Frogs and American Toads

Image of wood frogletImage of American toadSometimes it’s hard to stay on task here for all the frogs and toads living in every nook and cranny. I call it being Thwarted by the Warted. This summer as I was pulling remaining bits of Japanese stiltgrass in a spot that’s now mostly covered in native plants, a young American toad (right) popped out of the decaying leaves nearby. A couple minutes later, the smallest wood frog (top) I’ve ever seen surfaced too. Both made their escapes into the leaves of a fallen tulip tree branch.

American toads and wood frogs both find refuge in leaves and dense vegetation during the hot days of summer. In winter they have different strategies; toads burrow underground, while wood frogs take shelter in fallen leaves and produce an antifreeze substance to survive the cold.

The American Bumblebees

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Image of American bumblebee

Once among the most abundant bumblebee species in North America, the American bumblebee (Bombus pensylvanicus) is now highly threatened by the usual suspects: habitat destruction, pesticides, modern agricultural methods, and climate change. I spotted one of these little guys for the first time on ironweed flowers in late August; for the next couple of weeks I also saw them on wild bergamot blooms.

These bees make their nests on the ground or below ground in grasslands. They also nest in old rodent burrows (one of many reasons not to use rodenticides), abandoned birdhouses, and even cinderblocks or buckets. As with other bumblebee species, overwintering habitat is critical for the queens, who are the only ones left to start new colonies once spring arrives. Burrowing just below the soil surface, they wait out the cold season under the protection of fallen leaves and other decaying plant matter.

The Ringneck Snake

The floor under my bookcase isn’t the preferred habitat of ringneck snakes, but that’s where the poodle I was petsitting sniffed one out this summer. The snake was so wiggly and small that I worried about hurting her if I tried to scoop her up too quickly. An envelope and a glass did the trick.

Once outside, I found a rich spot of fallen leaves by the patio for her entry back into the wild. She had a little lint on her, but nothing a slide through the damp organic matter wouldn’t quickly wipe clean. Home at last from her basement adventure, she could now start the business of being a snake, eating earthworms, slugs and salamanders while trying to avoid being eaten by raccoons, owls, and even frogs, who can be both predators and prey of ringnecks.

These snakes are woodland dwellers, so their presence would not have been likely when this land was all turfgrass 20 years ago. During the winter, they hunker down in fallen leaves, rotting logs, stone walls or old mammal burrows—all of which are plentiful here.

The Meadow Fritillary and Silvery Checkerspot Butterflies

image of Meadow Fritillary closeup

Image of silvery checkerspot2These two little butterflies, the meadow fritillary (above) and the silvery checkerspot (right), are uncommon in my community and across the state of Maryland. Though I may have spotted them from a distance over the last couple of years, this summer they indulged me by showing up for some closeups in a planting right next to the driveway. They live here in part because we have plenty of host plants for their young: Meadow fritillary caterpillars eat violets exclusively, and silvery checkerspots lay eggs on wingstem (Verbesina alternifolia), native sunflowers (Helianthus spp.), and reportedly purple coneflowers (Echinacea purpurea) and some black-eyed Susans (Rudbeckia spp.).

But equally important to sustaining these butterflies’ life cycles are leaves and other decaying matter. Both species overwinter as caterpillars, with the meadow fritillaries waiting out the cold in violet habitat and the silvery checkerspots hibernating at the base of their host plants.

Unlike monarch butterflies, these creatures aren’t snowbirds flying south for the winter. Overwintering animals rely on us to protect leafy blankets and cozy stems and insulating stumps that make the lands outside our houses their permanent homes. It’s so easy to do, and so life-giving. And if we all did it, could it even be species-saving?

Photos: Luna moth by Will Heinz; all others by Nancy Lawson.

RELATED STORIES:

See my latest column in All Animals magazine: What Do Wildlife Need in Winter? Plants!

Learn more about life in the decay: Life After Death: Nurture the Decay

Leaves help restore microscopic life in the soil, too! Read a recent post by my friend and colleague, wildlife biologist John Hadidian, about soil organisms and health: Ground-Truthing

 

31 thoughts on “These Animals Are Made Possible by Fallen Leaves”

  1. Hey there. Thanks again for teaching me a new thing or two. This season, winter came a pasar a surprise while the leaves are still hanging mostly on their branches.

    I took your advice last year and left most of the leaves in place on the native beds but had a huge amount of work in Spring.

    This year I have no choice but to leave them where they fall, along with several plants and bushes that were never pruned.

    When Spring rolls around, will I be upsetting the critter’s habitat when I begin raking? When is it safe? I have numerous ground tulips and other early plantings that need to find their way to the light. Your thoughts?

    1. Hi Jaime!

      It’s a good question and a frequent one, and here really isn’t any one set answer to it, but I can give you some general guidelines. First, in areas with native plants under trees and shrubs, those plants are usually going to be woodland plants. So they are used to coming up through the leaves, and you wouldn’t usually have to worry about removing leaves at all from those spots.

      Different types of leaves break down more quickly, so that is a variable to think about. But I find that there are few areas where plants don’t come up among the leaves — sometimes I have started to worry about the Virginia bluebells, for example, because at first they seem sort of fragile, and I scoot the leaves to the side of some of them. But then I realize that it didn’t matter, because many others are coming up right through those leaves.

      I don’t really have much experience with tulips, though generally I’ve seen them come right through the leaves here too, beneath walnut trees.

      Animals live in leaves all year, so it’s really hard to say when a good time is. But your choice of tool — a rake — is definitely the best bet! If you need to rake some leaves but want to do the least damage to animals who might be in there, you can just move the leaves under bushes or to their own pile. I do worry about queen bumblebees, as this process could wake them up prematurely, so if you wait until the temperatures are warm enough for them to fly and find food, that would help prevent that.

      1. Thanks for the quick response. Yes, I use a “lady’s” rake with metal tines. Unfortunately, the critters replant a lot of my spring bulbs so ya never know. I like the idea of gently swooping up gobs (my words) of leaves in hopes of not disrupting the natural insect growth cycle. (Though not thrilled with Japanese beetles) I’m happy to see large numbers of bumble bees in my yard along with monarchs.

        I’m not concerned with my woodland gardens for the reasons you stated but I started planting over 20 years ago so my sunny areas are a jumble of natives and other varieties of imports.

        Thanks again. Love your site!

        1. I always leave the leaves from previous year as a protection from late frosts. The tulips and other bulb plants easily pierce though the old leaves without any problem. It actually gives a funny sight…

  2. Fully agree with this message. Up here in South west Nova Scotia more and more TV guests that discuss gardening topics are begging homeowners to leave the gardens alone. However, many home owners in the large cities don’t want a ‘messy’ neighbourhod and insist on the cleaning regimen. With continued articles, Face book notices, and TV appearances let’s hope there will be a marked change soon.

    1. Hi Dolores!

      It’s great to see so many organizations actively educating about this issue! Maybe with time more and more of the neatniks will hear the message. It’s encouraging that so many people respond positively once they learn just a little bit about this.

  3. I so agree with this in body, mind, and spirit. Our problem is the fever pitch concern over fire danger here in northern California. Everyone is bring pressured to remove big trees, shrubs, and dry leaves. We have nurtured our woodland and wetlands habitat over 20 years, including allowing most of the zillions of oak leaves to stay and decompose. Our insurance premium was doubled this year and many people in our area are having their policies cancelled. It’s a real crisis. We want to sell and move to WA but fear not getting a buyer unless we sterilize our land, with fire prevention being on everyone’s mind. Even if we have to stay, what if our insurance is cancelled?? It’s an untenable situation for many thousands of people here. I see heartbreak in our near future. Any words of wisdom would be most appreciated.

    1. What if the person who decides to buy thinks exactly as you do? You could hold off cleaning just in case you do not sell or seller is on your nature path. If a buyer wants it clean, hire a company to do that near the end of your stay. Perhaps less painful. Signing off as another person planting native and leaving the leaves.

    2. This makes me so sad. Your habitat sounds amazing. We are in a very different environment here, but the first thing that strikes me is that the type of woodland/wetland environment you’ve created probably retains a lot of moisture and therefore might be considered more fire-resistant, wouldn’t it?

      I’m not as knowledgeable as you about this, being in a very different environment here in Maryland. But I’ve been reading and learning a little about firescaping, and it seems like the one-size-fits-all solution of removal that you describe as being promoted is not what the experts there are really recommending. Jennifer Jewell has a new podcast about this on Cultivating Place, and the Butte County Fire Council recommends native plants and talks a lot about the importance of gardening in the region. One of Jennifer’s questions to them is about how to retain a natural garden: https://www.cultivatingplace.com/single-post/2019/11/07/FIRESCAPING-IN-HONOR-OF-THE-ONE-YEAR-ANNIVERSARY-OF-THE-CAMPFIRE-with-DOUGLAS-KENT-CALLI-JANE-DE-ANDA-BEN-TESTHART.

      It seems to me that raking up leaves that are up against the house is very different from raking up leaves in the woodland behind it, where they help to retain more moisture in the ground layer. But it sounds like the insurance companies don’t recognize those kinds of differences.

      This reminds me of recommendations here to remove all habitat because of ticks. In the end, removing habitat only further disrupts the balance by making an area even less inviting to wildlife who eat ticks and to predators of wildlife who carry ticks. We need that habitat for foxes, hawks and others who eat the mice carrying the ticks. And we need it for opossums and birds and others who eat ticks directly.

      I wonder if you could talk to the people who were interviewed in Jennifer’s podcast for recommendations? I don’t think they touched in the insurance issue, but maybe they would have some advice offline. I’m so sorry that you are experiencing this.

      1. Thank you so much, Nancy! I’ll listen to this and reach out to them. All insurance companies are losing money in CA so they’re not in a mood for nuance. Some are requiring inspections before policy renewal, which gives a chance for discussion, but others are cancelling outright. Homebuyers are turning away. The fear is palpable here, and where fear rules, logic loses.

  4. Nancy, Another great article ! On the subject of the importance of Leaf Litter, I would like to add that here in Southwest Ohio, our woodlands are being overwhelmed by Asian Bush Honeysuckle (Amur & Morrows). This plant is choking the life out of everything. One odd thing about it is that when it finally drops it’s leaves, they break down extremely fast, leaving behind NO precious leaf litter.

    1. Hi Terry,

      Thanks! Regarding the honeysuckle, we have quite a bit of that here, too. I hadn’t thought about its effect on the ground layer, but that’s a really good point. Yet another reason to try to get it out and replace it.

  5. Hi Nancy! We wanted the leaves and branches to be scattered on the ground for what you taught us on “The Humane Gardener”. One day, Patricio, the garderner, made a huge pile out them! I think he did it so it looked “cleaner”. So, now I’m putting them back where they were. But then again, there must be quite a few little animals living and sleeping under it.

    1. Hi Soledad! At least he kept them! A big pile is also good for wildlife. But having the leaves spread out will help the ground-foraging birds and others who like to just peck around for food there.

  6. I usually rake up, and mulch most of my leaves. I eliminated my lawn years ago. Now, after I mulch, I put the leaves right back in the spots I raked them from. Since the shredded leaves take up so much less space than whole leaves, I started taking leaves from my adjacent neighbors to fill in the bare spots. I have them blow the leaves they were going to bag, onto my property. I know they think I’m crazy, but it’s so obvious that this is the right thing to do. Changing the mindset of generations of this groupthink is impossible.

    1. Hi Mike, it sounds like you probably have some pretty amazing soil from all of those years of leaf mulch! You never know — sometimes the neighbors and others do come around a bit once they spot a certain thing that they happen to like in your garden, whether it’s a plant or a butterfly. Any time someone asks or comments on something growing or someone visiting, I tell them what exactly prompted that seedling to grow or animal to take up residence — whether it’s leaves or stumps or having the plants they need. … But yes, it can feel like quite an uphill battle sometimes for sure.

    2. I should also add here that, where you can, it’s best to not shred the leaves when you are trying to create habitat. Often a lot of these little creatures I’m highlighting here are already in the leaves; some are so small that we wouldn’t see them. I know that every property is different, and that some small properties have so many leaves on driveways and other hardscaping that it would be hard to find a place for all of them. And I know that vegetable gardeners find that shredded leaves are a great way to build soil naturally.

      But wherever possible, leaves left where they fall are going to be the richest habitat of all — and though people are often afraid of their plants not finding their way through the leaves, that’s usually not an issue if you’re gardening with native plants. They’re used to leaffall, especially woodland plants that grow naturally under tree canopy and shrubs and such.

      There’s been some confusion in social media about whether it’s good to mulch-mow lawns. For people trying to maintain lawns, it’s certainly better than blowing leaves away or bagging them up and sending them to the landfill. And it enriches the soil. But it doesn’t help those little insects and others who are already in the leaves. So that’s why I recommend getting rid of lawn altogether (as you did, Mike) even if you have to do it gradually. That way you can just leave the leaves everywhere. (And we use the leaves to keep killing whatever old/turf lawn is left here … it’s a long process due to the size of the place!)

  7. Thank you for the great article that I will share on our Garden Club’s FB page and in our newsletter. I too see many more species in my yard every year including American bumblebee (Bombus pensylvanicus) a first for me this year. If you build it they will come….”leave the mess!” is my mantra. Looking forward to many more sightings. Thanks for well written wonderful messages for all.

    1. Thanks, Cathy! And thanks for sharing with your garden club. That’s fantastic that you saw the American bumblebee too! He was so distinctive because of his large size and yellowness. It’s exciting that we can help them by making these simple changes. 🙂

  8. I’ve done a lot of things in my life that were less than perfect, but I got at least two things right. In the 25 years I have lived in my Maryland home, I have *never* raked the leaves. Also, I have used Roundup only once: On a stubborn patch of poison ivy a few years back. We don’t have a great garden in our half acre yard, but at least it has been a relatively safe haven for the critters.

  9. Thanks for this informative post. We also leave the leaves in our garden. I love the phrases that you use – life-giving and species-saving – to describe some of the benefits of leaving fallen leaves. Hopefully more people will respond positively to this message as time goes on.
    It is sobering to hear about the fire danger concerns in California that are threatening trees and wild habitats.

  10. There are orange salamanders all crawling around in the leaves, on the wooded mountain behind me in PA.

    I dug up some leafy mulch from the forest, for a basket where I was planting seeds, a few weeks ago. (I’m experimenting with planting a bunch of stuff in baskets this year. So far, they’re working well. I just happened to have a ton of baskets my dad was getting rid of.) All the other baskets were frozen solid that day, and I couldn’t break in to their soil to plant the additional seeds there. These baskets are exposed, sitting on open ground in the cold. So I went to the woods to gather more new soil.

    But on that same day, at the same temperature, all the forest floor was still thawed, all the leaves and rotten wood on the ground. Under the trees, where maybe the wind doesn’t blow as much, and maybe where microbes create heat, and because it’s a large thick layer without exposed objects sticking up like the baskets on the flat ground of my lawn, everything was warmer and there were even some live bugs still active in the soil. Bare dirt on open fields was hard as a rock on that cold day.

    1. Hi Nicole, yes, it’s quite amazing how protective that leafy layer is! How neat that you are able to see the salamanders there too. It’ll be neat to see what grows in your baskets and how it compares to the way things grow in the forest.

  11. I have a tiny lakeside yard with three enormous oaks and a huge maple. The leaves are overwhelmingly abundant. The oak leaves don’t really break down. AND the neighbor’s tiny yard is right next to mine without a fence and they are total neatnicks. I want to do the right thing for the creatures but it is kind of hard. I am slowly reducing the grass, seeding it with clover, etc. A mulching lawnmower is a bad idea, right? Should I rake onto my gardens to help ease the leaves blowing onto my neighbor? But I have to rake it up in spring, because nothing grows under thick layers of oak leaves, not even the tulips come through until I rake.

    1. Hi Nancy, I’m sorry I didn’t see this sooner. I think if I were you, I might try a few experiments. One way to easily reduce grass is to make new beds using piles of leaves, topped with twigs and branches to hold them down. You can smother the grass this way. The leaves will break down eventually, even if it is a slower process with certain species. As they break down, they’ll kill the grass and create rich soil for you. Then you can begin to plant in those areas — wildflowers, shrubs, a tree, native groundcovers.

      I don’t like mowing over anything because there are always creatures living in the fallen leaves and underneath. But if you want to keep some lawn, a mulching mower at least lets you break up the leaves into something smaller that will then add nutrients to your lawn without smothering it. It’s not my favorite option, but for people who want to keep lawns, it’s not the worst option. It at least keeps you from sending leaves to a landfill and helps you regenerate them back into the earth.

      When I have leaves fall on hardscaping, like the driveway and next to the house foundation and on the patio, I do need to move those leaves, so I put them under and around the trees and shrubs. You are right that some plants won’t come up through leaves — but most natives, especially the woodland natives, are used to having leaves on them and actually prefer it so they can have a blanket through the winter.

      I think you could try various things in different spots and then watch over time to see what happens. There is no one right way to do it because it depends on so many factors of your individual space — but the main thing to remember is that the more leaves you can leave in place and the more things you can leave undisturbed, the more wildlife, including bees and birds and butterfly and moth caterpillars, you will help. Hope that helps! 🙂

  12. I left my leaves alone, and my plant stalks alone, for the first time just last autumn and this past spring all my gardens went crazy with flowers. And these were oak leaves, they broke down very slowly. But that seemed to make it better for the plants, which were just covered in bees and butterflies. And there were birds everywhere, because they had so much to eat. I just keep a few walking paths mowed, everything else is now native gardens, and they’re so wild and beautiful and fragrant and mysterious, it’s become a little paradise.

  13. I have had the same effect here in southwest Nova Scotia, Canada…haven’t touched the garden in the last two years due to severe arthritis and it’s growing just fine without my interference. Enjoy all your articles. Thank you.

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