Leave the leaves
Polyphemus moth (left) cocoon on oak leaf in September, (right) adult in June.
I love anything nature. And so, as I watch the seasons change and the butterflies and bees disappear during the cooler weather, I wonder – where do they go?! For some people, fall cleanup means cutting tops off flowers and raking up the leaves with the goal of a tidy yard. The tidiness might look appealing to some, but for small creatures that live in and around your yard a tidy yard offers no shelter to survive the winter. Not only do leaves provide excellent nitrogen and organic matter that your winter grass will love, leaves also protect root systems and preserve soil moisture. Nature is highly intelligent and interconnected.
Many species rely on those fallen leaves for cover. Doug Tallamy says “the best place to leave the leaves is under the trees that grew them.” That's especially helpful for insects like luna moths that are found in the canopy of trees, then drop to the ground to overwinter as larvae cocoons curled up in oak leaves. Some butterflies and moths find their way as eggs, caterpillars, or pupae into leaf litter or compost piles.
The long journey of a monarch butterfly is unusual. Monarchs are the only pollinator that travels great distances. Even though I’ve stood at the foot of the Mexican fir trees in awe of 10,000’s of overwintering monarchs, it’s still unbelievable that those delicate butterflies can survive that long journey. The rest of the pollinators don’t go far, in fact most stay right in your back yard over winter.
Leafcutter bee nursery in stiff stem, October
Some small bees such as long-horned or cellophane bees hunker down inside hollow plant stems such as joe pye, bee balm, stiff goldenrod and purple cone flower.
“Just like with people, we should be celebrating diversity with bees. Each species is a very important piece of the puzzle that is ecosystem stability. Understanding their life cycles, and how they make it through the most tumultuous time of year is just one step toward improving local habitat for these essential critters. Most bees have a much longer history with this land than any human!” Beeandbloom.com
Most bees in North America are solitary. During the warm season, a single, mated female will tend a nest in a ground tunnel. She will work through an active season until her death, leaving behind several offspring with enough food to help them develop properly through the rest of the warm season.
During cold months, dead plant stems, old bark, cane, leaves, and undisturbed soil are the secret winter homes of pollinators. Leaving piles of leaves, compost or wood help all manner of creatures including salamanders, beneficial insects, and pollinators. Many solitary bees like mason bees burrow under tree bark or wood piles. Some have gorged like bears to make it through the winter; others wait in suspended animation as larvae, pupae, or eggs.
Something you should be aware of as you begin to tidy up your garden for winter - especially burning or removing the plant stems, you may be destroying hibernating bees or bee nurseries. So, it’s important to leave plants standing until late spring when temperatures rise and nectar and pollen is available.
Bumble bee queen burrowing underground in the fall
In the winter, bumblebee queens live as solitary individuals. Without the help of a colony, a mated queen survives winter in a little underground burrow such as an abandoned mouse nest and remains dormant for months until spring (May) when she emerges, builds a nest, lays eggs and feeds the young until they become a new colony of adult bumble bees.
So, now that you know many species are counting on you to leave soil undisturbed, piles of leaves untouched, and shrubbery unpruned over winter, you can feel good about being the untidy gardener! And if you’d like to fashion some homes for bees, that’s entirely possible. Find out more here about nesting habitat here: https://xerces.org/blog/5-ways-to-increase-nesting-habitat-for-bees
READ MORE ON WINTER HABITAT: https://xerces.org/blog/leave-the-leaves
LEARN MORE ABOUT BACKYARD HABITAT: https://www.pollinatorfriendly.org/habitat