The neighbors’ leaf pile looked even bigger than usual this year. And, so, it pained me even more to watch it ignite. Like many in my county, they regularly burn their yard waste.
The wet leaves produce extra-heavy smoke. (They also release loads of carbon monoxide and some known carcinogens, too!)
Other folks bag their leaves. Some bags head to landfills. Others are composted elsewhere. For my part, I used to remove every last stalk and fallen leaf to compost in my own bins.
But, when it comes to the overall health of our landscapes and the productivity of our gardens, none of these practices is exactly ideal.
Turns out, those leaves and plant stalks do a lot more good when left in place—or when they’re only slightly rearranged during garden cleanup. Taking this more relaxed approach helps to provide crucial habitat for overwintering pollinators, mammals and even amphibians.
It also works in our favor by insulating perennial plants’ roots and enriching the soil for next season.
Stalks and Stems
“Depending on where you live, you can easily have 30 to 40 different native [bee] species in your garden,” says Matthew Shepherd, Director of Communications and Outreach for The Xerces Society for Invertebrate Conservation. “People don’t always realize there’s this level of diversity, because, when we think of bees, we think of honeybees or bumblebees.”
But in North America, there are more than 3,600 native bee species. “They’re all facing the same problems with pesticides and lack of habitat,” Shepherd notes.
Many native bees actually live inside hollow plant stems, so leaving these standing can be hugely helpful to these valuable pollinators. “If your stems are 18 inches to two feet tall, you could probably get away with that without your neighbors complaining too much,” he says.
As for taller plants?
“You don’t necessarily have to leave the entire stem,” Shepherd says. You can simply trim these down to the 2-foot level and then loosely pile the cut stalks in an out-of-the-way spot. This enables any native bee occupants to safely remain there all winter and emerge during warm weather.
“They need a full year of stability in their nest,” he explains. “For some of those bees, they won’t be adults until May or June or July. So, if you’re taking those stems out in spring, you’re doing away with any benefit you might’ve created.”
Leaving the Leaves
As with native bees, Shepherd notes, “There are also dozens of butterfly species that are threatened, declining or rare across the country.” Many of these, including some swallowtails and luna moths, overwinter amongst fallen leaves. So, when you remove the leaves—or shred them—you’re doing away with some of next spring’s butterflies.
“With the leaves, the idea is you can leave them in the back of your flower border or at the base of a hedge row or wherever to allow them to rot down,” Shepherd says. “They provide the longer-term cover for the beetles and the caterpillars and other things that might be sheltering in there or they just break down and help the organic matter in your soil.”
He adds, “We’re not saying you have to keep all the leaves. And you don’t have to leave them everywhere. It’s perfectly fine if your grass needs to be raked. Then rake it, but take the leaves, and, if you can put them in a corner somewhere, that’s great.”
If you do pile your leaves inside flower beds during garden cleanup, be sure to leave a little space around the crowns of any delicate perennials to avoid smothering them.
Wondering what the neighbors will think? There are some things you can do to counterbalance the less-than-tidy look.
First, telegraph that the garden cleanup moves you’ve made are intentional by trimming any tall grass along the outer edge of your planting beds. Likewise, neaten any bricks, blocks or other hardscaping features you may have put in place to help delineate the perimeter of your gardens.
You might also install bird feeders, pretty stones or even a solar-heated birdbath to add extra interest inside your overwintering gardens. And, if you chose to trim back extra-tall stalks, consider arranging some of these in a tent- or teepee-like fashion. This can add still more visual interest and provide windbreaks for birds and other small creatures.
Want to go the extra mile? The Wild Seed Project offers an attractive, free “Leave the Leaves” sign. Have it color-printed and laminated—or place it in a protective frame—to display outside for any curious passersby.