Pollinators: ‘Leave the leaves’
As gardeners, we care about the planet. We nurture the soil and plants to have healthy harvests. Some of us garden to provide food and habitat for animals and birds.
Others may be gardening for pollinators to ensure they survive so we can continue to have the varied fruits and vegetables that we enjoy and need to live.
We carefully plan the right balance of food sources for different species of bees, wasps and butterflies so they can find enough food in all their stages of life. We scour the plant lists for native plants that offer the most nutritious food.
We provide water sources of different depths and add sticks and rocks within a bird bath to keep pollinators and other beneficial insects from drowning. We add areas of sand, gravel, and loose soil to our flower beds and prune stems or hang clusters of hollow tubes / stems for nesting sites for tunnel and cavity nesting bees.
As temperatures drop, days get shorter and fall is firmly entrenched, we no longer hear the buzzing or see the pollinators flying about. Where do they go once it gets cold?
While the much-celebrated monarch butterflies fly south for the winter, most pollinators overwinter in one of their stages of metamorphosis, including some monarchs.
Clearly our job of gardening for pollinators is not finished for the season. How can we provide safe shelter for these overwintering insects?
The pollinators say, “Leave the leaves and save the stems.”
Many insects lay their eggs on fallen leaves and beneath the leaf litter. Some use leaves as camouflage like the luna moth (Actias luna) who wraps its cocoon in leaves and the swallowtail butterfly (Papilio spp.), whose chrysalis resembles wrapped curled leaves in shape, color and texture.
Others like bumble bee (Bombus spp.) queens burrow in shallow cavities beneath the soil and need the insulation from the leaves above to survive the winter cold.
Stems and branches of trees, shrubs, bushes and perennials provide nesting cavities for many pollinators. Leaving dead flower heads, including bolted vegetables, provides winter food sources for wildlife as well as visual interest in the winter garden. In the spring these can be pruned at varying heights to allow nesting cavities for that year’s emerging pollinators to begin the process for another year. Allow the old stem stubble to decompose naturally.
Fall yard cleanup for pollinators should include leaving the leaves where you can without smothering your grass, keeping them whole so the eggs and larvae are not mulched with the leaves and moving them to flower beds to provide cover and spring mulch for the beds. Finally, creating small piles of sticks for shelter and leaving dead stems on plants round out the basic steps.
We understand many gardeners want to keep a beautiful landscape, but also love pollinators. Protecting our pollinators can be balanced with a nice looking landscape. Mulching mimics the humus layer of the soil in forested areas — that is just one way you can keep things looking nice while protecting pollinators.
Tidying up plants by cutting down partially can help but try to leave the stems you cut to decompose naturally. Chop excess leaves with a mulching mower or chopper and add them back to the landscape as a mulch.
For more details, go to https://go.osu.edu/living
Cubick is an Ohio State University Extension Master Gardener Volunteer in Mahoning County.