November 19, 2024 | By Cassy Hallman, Conservation Ecologist at DSBG
As you stroll through Holidays at the Garden this winter and reach our Piedmont Prairie, you might find it looks a little more wild than other areas of the Garden. The natural sprawling grass intermingles beautifully with the holiday light displays, but you might be wondering why we don’t mow the Prairie to make room for more light displays.
Grasslands such as our Piedmont Prairie Habitats at DSBG are dynamic environments that thrive on disturbance. Historically, wildfires and the grazing of large mammals such as bison kept these once-common landscapes free of trees and woody species, providing ample sun for our light-loving wildflowers. These wildflowers in turn provide nectar, pollen, fruits, seeds, and habitat for our most charismatic fauna – like songbirds, butterflies, bumblebees, fireflies, ladybugs, tree frogs, and small mammals.
Mowing and burning these prairies is crucial for keeping woody vegetation at bay and allowing a diversity of grasses and wildflowers to thrive. However, resources are scarce in the winter months, and local wildlife needs the seeds, fruits, and cover from predators that these grasslands provide. In previous years, these prairies were mowed to make way for Christmas lights. This year, lights and life coexist in harmony, as large swaths of vegetation will stand through the coldest months.
An often-overlooked role of many native species is their ability to be host plants. Many insects, especially butterflies rely on one or a few specific plant species to lay their eggs on. These larvae are adapted to feed on the vegetation of only these so-called host plants. When these plants become less common in our landscape due to the lack of wildfires and roaming large mammals, increased development, and the use of herbicides, butterflies can’t lay as many eggs and their populations decline. Properly managing and expanding species-rich grasslands can help these pollinators thrive.
By not mowing this winter, our Piedmont Prairie Habitats allow the next generation of butterflies to overwinter as eggs or as caterpillars. They are currently hiding in host plants such as the hollow spaces of flower stalks, in leaves on the ground, or in silk-tents and chrysalises. Other insects, such as wild bees and beetles also find space in stalks, leaf litter, and undisturbed soil. These pollinators will emerge in the spring to a world once again filled with nectar and pollen, helping to pollinate our gardens and crops and acting as food themselves for birds, amphibians, reptiles, and mammals. Skipping mowing this winter ensures this prairie ecosystem will continue thriving in the years to come. Check out the images below to discover some of the creatures who call the Piedmont Prairie home this winter!
Butterflies that overwinter at Daniel Stowe Botanical Garden:
Eastern tailed blue butterflies overwinter in bean and pea pods.
Eastern Tiger Swallowtails overwinter in a chrysalis on various substrates.
Zebra swallowtail butterflies overwinter in a chrysalis attached to paw paw trees.
Luna moths overwinter in a tightly wrapped leaf-cocoon in undisturbed leaf litter
Lon zabulon (Zabulon skipper) overwinters in a chrysalis on several different grass species.
Vanessa virginiensis (American Lady) overwinters in a web-like structure atop Everlasting plants, such as Pseudognaphalium obtusifolium.
Resources
https://extension.unh.edu/blog/2019/10/how-help-bees-butterflies-survive-winter
