a saner approach to fall cleanup, with the habitat network’s rhiannon crain
WHEN WE SAY, “fall garden clean-up,” just how clean do we mean? A slightly tongue-in-cheek campaign called “The Pledge to Be a Lazy Gardener,” from the Habitat Network, asks us to think about that in a whole different way than what you might find in the how-to section of ornamental-horticulture books.
Backstory: The Habitat Network collaboration between Cornell Lab of Ornithology and The Nature Conservancy, empowered by a mapping program called YardMap, provides a suite of tools that helps you map, and then manage, your own home landscape ecologically, to be a better habitat style gardener. The information in the maps you create in this citizen-science project helps researchers learn about wildlife interactions in residential landscapes, and more.
I asked Dr. Rhiannon Crain, The Habitat Network project manager, to talk about rethinking fall clean-up from an ecological point of view, and I’ve got some tips of my own as well. Read along as you listen to the Oct. 23, 2017 edition of my public-radio show and podcast using the player below. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).
an ecological fall cleanup, with dr. rhiannon crain
Q. Before we get started being lazy gardeners, let’s give people a little update on the Habitat Network, and the YardMap suite of tools. You and I talked about it around a year ago, but how’s it doing? How many acres are mapped? How many people are participating, and what’s going on?
A. We’ve just surpassed half a million mapped acres, which is a pretty significant number for us; very excited to see that come and go. And we’ve got about 48,000 folks who are a part of the network in various forms or another. Some folks follow along on our e-news [sign up at this link], and try out some of the activities that we suggest. Others are really dedicated mappers [sample map, below], getting in and doing not only their yards, but their favorite nature spaces, where they watch birds, or where they take their walks with their dogs.
So I’d say we’re doing pretty well. We’re in the midst of a massive redesign, which is going to streamline some of our mapping tools, based on the feedback that we’ve collected from our users over the last few years. The group is really excited about that opportunity.
Q. And the Lazy Gardener Pledge—what’s behind that campaign?
A. I think we really recognized that participating in citizen science can be a really heavy lift for some folks. They’re not quite at a place in their lives where they can devote several hours to mapping their yard, and staying on top of that map. We wanted to find a way to connect with people that didn’t necessarily require that big of a commitment, so we thought of this pledge idea.
We know pledges are sort of something that you see around on the internet sometimes, but they really are an interesting way to create a connection with folks, and get them to think a little deeper about the kinds of practices that they’re engaging in.
So we set out on this pledge. We’re doing pretty well for the short amount of time that we’ve done, and folks are really expressing a lot of pleasure in the tongue-in-cheek nature of this, and reporting that there’s some really cool conversations that they’re having around the idea of lazy gardening—which you and I know nobody who’s doing wildlife gardening is lazy at all.
Q. No, no, no, no. And I always wince when I see, “Easy! No Care! Instant! Year-round color!” All these promises which are just so silly, because of course gardening is hard work.
So, for context, before we dig into the campaign—the pledge—and the principles behind it, I’m in the Northeast in Zone 5b and we can have frost by late September, but usually in recent years it’s more like mid-October. And you are in?
A. I’m the Coastal California ecoregion; I think 9b is my actual planting Zone, USDA-wise.
Q. Right. And so, how cold do you think you get in the winter?
A. We get a few days a year where it will get below freezing, but it is not the norm.
Q. O.K., I bring that up just so that people know, if you and I are trading some anecdotes along the way, that they know where we’re at. And also that this is for everybody; it’s not about one region or another, this is for everybody, The Habitat Network.
A. Yeah, absolutely.
Q. So our garden clean-ups probably involve different timing, and different chores, I suspect. Right now it’s the beginning of October, while we’re taping this, and I’m kind of waiting for the trigger, the nature triggers, to start to collapse some of the big amounts of foliage and for the leaves to fall. I’m waiting for the cold triggers, right?
What are some of the first things you do in garden clean-up out there? What are some of the earliest things?
A. Well, we certainly keep horticultural plants in my garden. When you called up to start this interview I was actually out pulling some pumpkin vines that didn’t have actual fruit on them. So I’ve got a couple of those regular things that still happen here.
My wildflowers are looking pretty shabby at this point, most of the seeds have been stripped out of most of them, because winter is just not the same here. We’re actually heading into our growing season. So I’m going to cheat a little bit on this fall pledge, living out here in California, and I’ll likely do some pruning here in the next month. It’s the same kind of pruning that I would expect someone in the Northeast to be doing in March if they took The Lazy Gardener Pledge.
Q. Right, good; that just helps people, as I said, with a little context.
When people sign The Lazy Gardener Pledge on your Facebook page or website it says; “By submitting this survey you pledge to leave your garden messy for wildlife.” [Laughter.] So what are some of the messes we want to encourage? Let’s go through some of the principles. [The link to take the pledge at Habitat Network.]
A. The one that I had never thought about before getting involved in this project was the leaf litter. I think that the ecology of leaf litter is surprising, and engaging, in a way that you might not think. A lot of species of Lepidoptera, so these caterpillars, they will leave their larvae and their eggs on leaves from trees, from their host species, in the fall months, September or August. [Above, giant leopard moth caterpillar on a fallen maple leaf at Margaret’s.]
And those caterpillars will either grow up and eat some of the leaves, and then roll up and pupate in the leaf over the winter, and those leaves will fall to the ground. In a normal forest setting you would expect those leaves to still be on the ground, maybe be compressed and smushed and buried a little bit, but those emergent insects would still be near their host tree when they emerged.
So we have a practice in most residential yards of scooping up the leaves and, at worst, bagging them up in plastic sacks and sending them off.[More on the benefits of “messy,” and on how to make “messy” look good.]
Q. Oh, I know.
A. A lot of people will mulch them, which you can imagine there’s high mortality for caterpillars in those sorts of cases, too. Or there’s other people who will leave them, or brush them under their perennials, and flower beds, and stuff. So you can imagine that some of those caterpillars are never going to emerge. Some of them are going to emerge and be quite far from the host species plants that they need to eat, or lay their eggs on. And some of them are going to find that they’re not too far away.
So that would be a really interesting example for “The Lazy Gardener Pledge:” Leave those leaves alone. Let those caterpillars, that are there, be at home when they emerge in spring.
Q. So obviously if you have giant oak trees, like I have at the perimeter of my property, very, very, very old oak trees, and a lot of maples and so forth. Tons of leaves, the whole place is covered.
Maybe I can move them to the edge—nicely move some of the leaves, you know what I’m saying? We don’t want to suffocate the entire place. Thick layers of leaves can be slippery, can be a mess, can kill whatever is underneath. All gardens are kind of a contrivance obviously, so we want to, I don’t mean to say err—but we don’t want to go too far in one direction and also have a mess on our hands.
So maybe we find places where those leaves can lie where they fell. For instance, I can think in my own yard at the fringe of the property, I could let the leaf litter be as deep, for as many years, as I want, because there’s all these old trees. And they’d be really happy to have that on their feet, on their roots, and the caterpillars would be happy. Maybe in the middle of my front lawn right by the house I’m going to rake the leaves and move them to somewhere more appropriate. So that’s O.K.?
A. Exactly. That kind of moderation, leave them when it makes sense, there are some places that need to be cleaned up. I have big, non-native, sweetgum trees [Liquidambar styraciflua] that I inherited when we purchased our house, and we put in an impervious driveway of decomposed granite. I can’t leave the sweet gum leaves on there all winter, through our rainy season. It would turn my DG into soil, and then I would no longer have a driveway I’d have a new meadow. [Laughter.] So I move those off into areas where I don’t mind leaf litter piling up. And I don’t have any problem with that.
Q. Right. I did read the tenets of the pledge, so I’m going to skip ahead for a second in this comment. Leaving the leaves reminds me of one of the other principles that comes later in this pledge, which is to leave snags, or wildlife trees standing—dead and dying trees standing. It’s about biomass, it’s about that this is all this biomass, this living material or formerly living material, from this miniature version of this ecosystem. It grew up there, it was produced there, and it should decompose there too, right? That’s an overriding principle.
A. Yeah, I think that would be a wonderful guiding sentiment. The snags, people don’t think of those necessarily as fall garden clean-up, and it’s a little bit of a stretch for this particular pledge. But the value of them, there’s so many kinds of wildlife, it just can’t be ignored. Many people will trim up trees during the fall, so we put it on there for that exact reason. [More about snags, from The Habitat Network.]
Q. To really think of the word “sustainable,” if you were a sustainable farm, let’s say, you would try to bring in as few inputs, as few materials in bags—like you talked to me before about carting away the leaves in bags, which is bad—you’d try to bring in as few and take away as few. In other words: be sustainable. Not in other words; that’s the word. [Laughter.]
So you’re encouraging us to think that way about our gardens, and about the benefit that gives to wildlife. I had a dying birch tree. Very, very old, twin-trunk, birch tree; very, very big. And it was dropping its top, big pieces at a time. So I topped it, made it stable, but left up most of the trunk, and I even dropped the rest of the trunk beside it, and I’m letting it decay there over the years because it’s full of food for so many creatures, isn’t it? [About Margaret’s birch “snag” shown above.]
A. Yeah, it’s absolutely full. So many insects will get in there, live their entire lives on that decomposing log, and then become food sources for all kinds of little critters, depending on where you live. Little mammals, birds—everyone is looking under the bark when they’re hungry.
Q. I know, it’s incredible. And it’s become this like outpost, this command center. Everybody is like, “Let’s see what’s going on.” It’s a perch, and the pileated woodpeckers are carving out the back of it; everybody’s busy in there. So it’s kind of fun.
So what else about the pledge? What other things? We’re leaving our leaves, we talked a little bit about snags …
A. There’s obvious ones like leaving those flower heads on, that the seeds that they produce are available for wildlife. This is really important, especially in places where you get a snow cover, a blanket of snow, because a lot of the foraging opportunities are then hidden under that snow for birds. The little critters are better at tunneling round under the snow, but the birds they really do need stuff that’s above the snow.
So when you get, especially Joe-pye weed, stuff that will have structural integrity, and leave those seedheads thrust up through the snow, those are incredibly valuable resources for birds during the winter months. And they’re kind of cool, too, when you get to look out across your snowy landscapes and see those stark, black, structural elements still there. I, at least, enjoyed it when I lived in the Northeast, being able to gaze out and see that contrast.
Q. A lot of the daisy family plants really do this in the garden, they have that kind of persistent wildlife value, and birds will use … the obvious ones are coneflowers, that people think of, although where I live those are not native particularly. But the sunflowers and so forth, those are the things the birds will pick over month, after month, after month.
A. Because they can become home for insects too, that are also in there, eating the seeds, and the decomposing … especially the big fleshy ones like sunflowers, so it becomes a protein source, too. [Above, insects on fading sunflower.]
Another interesting one, people have goldenrod. The flowers on goldenrod are great, and the seeds are great, you’ve got goldfinches that are relying on those during their nesting season, even to feed their young. You’ve probably walked through a field of goldenrod and seen those galls, that are really commonplace on goldenrod plants, those all contain beautifully preserved little protein snacks for birds. Birds will actually seek out those galls during the deep winter months, when they are hungry and could use a good meal, they’ll bore into them and take out the little larvae over winter. And so if you’re chopping down those goldenrod plants, mowing that meadow in October, you’re removing that opportunity for a pretty nutritious meal. [On goldenrod galls, and the benefits of a “messy” fall-into-winter garden; fall and winter gall photos above from The Habitat Network.]
Q. So what I’m hearing you say, and something that I often say when I lecture to gardeners and so forth is, “Don’t clean up too soon, and don’t clean up like you’re vacuuming the living room.” In other words, cleaning from one corner to the opposite corner, every square inch. You’re telling us, “Tease it apart, leaving any high-value materials up for as many months as you can.” Yes?
A. Yeah, I think that’s a great bit of advice.
Q. So, we’re leaving our leaves. Dried flower heads–and they’re beautiful frankly, like you said, that visual out the window of them jutting through the snow, but they have that sustenance value. And what other things are we doing?
A. Once you’re starting to think about this, another interesting thing to do once you leave your messy garden, is to look around and look at what kinds of persistent berries you have available in your yard. Fall is great time to take stock, to see if you’ve got some fruits that are persisting into October, December, January.
One of the things we recommend you do is to take our principal planting palette that we created. That helps you to identify the plants in your yard, and to figure out when those fruits are available in your area, and then let you take counts so you can see if you’ve got what we call “functional redundancy” in your garden.
You can look across every month, and look down and see, “O.K., I have three berry sources in June; five in August. Woops, only two in September, zero in October.” And you can start to pick plants then that will fill out those fall and winter months with some species of berries that we know persist longer into the cold months. [More on the palette, and a downloadable blank calendar (above) to use to chart your garden assets.]
Q. “Functional redundancy?”
A. So, “function” of providing food, and “redundancy” in that you have more than one source. So you’re looking to make sure that, if you’re an advanced habitat gardener especially, that’s a really great goal to aim for.
Q. And I often say, again to gardeners when I’m giving a talk, “Hey, you’re shopping in the shrub aisle at the garden center next year, and even it was all alphabetized and you were under “V” for viburnum, not even all viburnums fruit at the same time.” I have viburnums that fruit in July and August and are gone—the fruit’s gone—and I have some that hold on until January. It’s like the persistence of fruit, and making those observations is so important, I think. Because of what you’re saying—we don’t want to have, “Hey, come to the buffet!” And then it’s like, “And now there’s nothing here for 11 months of the year after that.” [Laughter.] That’s no good, right?
A. No, that’s no good. Birds do migrate locally, but boy, it is a lot easier on any resident birds that have taken up in your particular yard, if they do not have to wander too far to forage, especially during cold days. When you’ve got a chickadee that will burn up 60 percent of its body fat on a cold night, and it needs to build that back up every single day. The farther it has to fly to do that, the less likely you’ll be to see that bird survive the winter. And birds can, and do, die in the winter when it’s cold, if they can’t find enough food.
Migration is a risk, and so is staying around for the winter where food sources are scarce. So the more you can build up that functional redundancy in a yard, the more likely any given organism is, that chooses you, will make it through.
Q. O.K., I’ve made a big asterisk on my notepad here, “functional redundancy.” I think I have a lot of it going on, but I’ve got to really look that up and learn more about it. I love the idea. What other things? What about brush piles? I always see that listed; is that in part of the pledge?
A. It is. If you do have fallen branches, we recommend stacking them up, and making a brush pile, probably off to the side, away from the main areas of the yard you use. Do you have a brush pile? [About making brush piles, and why to have one.]
Q. I have so many brush piles I’m just turning into one big brush pile! [Laughter.] I have a 2-point-something acre garden, and I’m surrounded by very old woodland, a state park, so we’ve got a lot of woody debris. And it’s a windy site too, so stuff’s blowing in, so I always have a brush pile that I’m not removing. Obviously I have to remove some debris, but not all.
A. It sort of swings back around to what we were talking about earlier with your birch tree, and being able to leave it where it falls, that is something that someone with a really large yard, and a really convenient tree that fell in a convenient location, can do. But that’s not always the case. Sometimes something will fall right next to your house, or in the middle of the area that you keep as lawn, and you need to do something with that wood. And we think rather than chopping it up and sending it away, or chipping it, a brush pile is a great alternative.
And so you get to keep that wood on site. You get those sustainable benefits that we were chatting about. And you also create a kind of interesting little micro-habitat, where the wood is both decomposing, but also creating structures for birds to forage underneath. So, a pretty safe place to forage. You can’t get caught by a hawk when you’re digging around under a brush pile.
You’ll get other cool things happening around a brush pile, too. They’re really great for insects, and some of the salamander species that might be endemic to your area. They’re pretty valuable, they’ll act as hibernaculums, so places where things will hibernate.
Q. Yes! I always think of that word as relating to snakes, going into their winter residence. But at any rate … also on the list …
A. You don’t want to talk about snakes? [Laughter.]
Q. Well, I like snakes so I don’t mind talking about them, but every time I talk about them everybody’s like, “Aaahhh!” [Laughter.] So, it’s one of those tricky subjects.
A. It sure is.
Q. But they’re good pest control; they’re wonderful animals. I do like them.
Obviously in The Lazy Gardener Pledge it tells us not to use chemicals, and I feel like this is an organic gardening radio program, and we’re talking about habitat gardening. We don’t want to kill soil life, we don’t want to kill insect life, which is what sustains birds. We don’t want to be spraying chemicals. But the thing that was on the list, that I want to take some time in these last few minutes to talk about, there was one item that said, “Wait until after several 50-degree-Fahrenheit spring days to clean up again.” Tell me about that; that was something new to me.
A. I think that’s mostly related to some of the insects that are overwintering. A lot of them are going to be pollinators so you’ve got your bees, and we talked a little bit about the Lepidoptera earlier. They’re all going to be triggered by something to wake up in the spring, and that something appears to be a steady stream of 50-degree days … “wake up” is not quite right, but I think it’s adequate here …and they go about the beginning of their life cycle. So they become mobile, they’re no longer as vulnerable to lots of the spring cleaning actions that would either kill them, or move them some place that they don’t necessarily want to be.
That’s exactly where that idea of waiting until those 50-degree days comes from. So you’ve got bees that are underground that will wake up and emerge—something like a native cellophane bee. Lots of things will be waiting for those warm cues, and then emerge. Under the tree bark, the galls in the goldenrod—almost everything is waiting to emerge until you get some sort of weather cue. [More on making native pollinators at home.]
Q. So again, we’re going to be a little lazy and not clean up too soon at the other end also, and that kind of completes the cycle of this Lazy Gardener Pledge [laughter] that the Habitat Network is promoting this fall. It kind of goes into the spring as well really.
A. Yeah, until you’re getting deep into spring; then it’s warm enough.
Q. Well, I love it. And I love that you’re always educating. It’s not just where we come as gardeners, and we map our gardens, and we use the tools and so forth, and that’s it. But you’re always educating us, and in this way, a little bit of a playful way, with this pledge–upping our game, adding knowledge. And that’s what I especially love about the Habitat Network, and YardMap. I’m so glad to speak to you again, and happy garden clean-up over there … or not. [Laughter.]
A. I’m awaiting. [Laughter.] I’m very excited to do my perennial trimming up here.
more from the habitat network
- My previous interview with Rhiannon Crain about mapping your yard
- The benefits of “messy,” and on how to make “messy” landscaping look good
- Tools to develop a supportive planting palette
- Take the Lazy Gardeners Pledge
- The Habitat Network website
- Subscribe to The Habitat Network’s e-newsletter
cleaning up diseased or infested plants
AN EXCEPTION I make to being generally nature-focused when I clean up the fall garden is with diseased plants, and those with a serious insect infestation–or prone to insect pests, like Brassicas are to cabbage worms. Good garden sanitation in the fall to remove delicious overwintering places can help, so I don’t just leave spent troubled plants standing. More on special cleanup tactics for my key pests, from squash bugs and cucumber beetles to those cabbage worms and more. Had any serious fungal diseases, such as with peonies, or roses? I’d clean up extra-carefully under those and discard the spore-covered debris, too.
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MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its seventh year in March 2016. In 2016, the show won three silver medals for excellence from the Garden Writers Association. It’s produced at Robin Hood Radio, the smallest NPR station in the nation. Listen locally in the Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) Mondays at 8:30 AM Eastern, rerun at 8:30 Saturdays. Or play the Oct. 23, 2017 show using the player near the top of this transcript. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).