Yes, You Can Skip Your Fall Cleanup

The weather turns crisp, leaves are turning colors (and littering your property), and your garden is starting to fade as plants go dormant in preparation for the winter ahead. That usually means it is time for a weekend (or three) raking up leaves and pruning spent plants. Or does it? Turns out, leaving your property and gardens to their own devices is a good thing! Tired plants and piles of leaves serve important roles in supporting the pollinators we love. It also contributes to better overall garden health.

Pruning perennials in the fall is a common gardening practice aimed at maintaining plant and garden aesthetics. However, it's essential to consider the ecological impact of this activity, particularly on native insects in Groton. Native insects, including beneficial pollinators (like mason bees and hover flies) and other arthropods, play crucial roles in the local ecosystem.

Many native insects use perennial plants as overwintering sites. When these plants are cut back in the fall, insects such as bees, butterflies, and beetles can lose critical habitat. Species like butterflies, preying mantids, and numerous moths use the stems and leaves of perennials to lay eggs or as pupation sites. Removing these plants can disrupt their life cycles and even negatively impact the biodiversity of your garden. Some native bees, especially solitary bees, use hollow stems of perennials as nesting sites. Cutting these stems in the fall can destroy their nests and reduce bee populations.

Mason Bee in leaf litter

Perennial plants often provide food sources for native insects late into the fall. Late-blooming perennials, such as asters and goldenrods, provide essential nectar and pollen for insects preparing for winter. Pruning these plants too early can deprive insects of these critical resources. Also, many insects and birds feed on the seeds of perennials like purple coneflowers. Leaving seed heads intact can provide food for insects and other wildlife during the colder months. It also gives native seeds a chance to spread naturally, saving you the need to purchase new plants.

Look closely, do you see the birds on the sunflowers? How many do you count?

The foliage and debris from perennials create essential microhabitats for various insects. Fallen leaves and plant matter provide shelter for insects and other small creatures while also enhancing soil health. This organic layer helps retain soil moisture, benefiting soil-dwelling insects and serving as a natural mulch to protect tender shoots in spring. By not raking, you save money, time, and effort by utilizing what's already in your garden, reducing the need to buy and spread mulch in both fall and spring.

Leaf litter and small twigs make a mulch that is beneficial to your garden.

Pruning perennials in the fall can have negative impacts on native insect populations in Groton. By adopting more mindful pruning practices, you can help preserve the habitats and food sources that native insects rely on.

But fall is a crucial time in Groton to prepare gardens for the coming winter months. So what should you do?

Selective Pruning: Rather than cutting back all perennials, selectively prune only those that are diseased or heavily damaged. Prune plants that benefit from autumnal trims like lilacs, irises, and peonies, but leave healthy plants standing to provide habitat and food for insects and birds, like coneflowers, daylilies, and sunflowers.

Delay Pruning: Come spring, your garden will look MESSY! Remember, you are doing it for the butterflies and bees! Be patient and delay your pruning until night-time temperatures average 50 degrees, ensuring that insects are less dependent on the plants for habitat and food. This allows insects to complete their life cycles without disruption.

Delay pruning until spring.

Leave Debris: Allow leaf litter and plant debris to remain in the garden. This provides shelter and nesting sites for insects and other small wildlife. In the spring, when you finally break out the pruners, consider cutting plant material into 1"-2" sections and letting them remain in your garden as a ground cover. The Native Gardens at Town Hall, which are maintained by the Groton Garden Club, use this method to support insects and to eliminate the need for mulch.

Create Insect Hotels: Supplement natural habitats by “creating” insect hotels using cut stems and other materials. These structures can offer additional nesting sites for solitary bees and other insects. Be sure to read up on the best practices for insect hotels as, if done incorrectly, they can become a buffet for predators.

Create an insect hotel in your wood pile

While fall pruning is often considered a vital part of garden maintenance, it is crucial to consider its ecological impact, particularly on native insects. By embracing more sustainable and mindful pruning practices, such as selective and delayed pruning, leaving plant debris, and creating insect hotels, you can balance garden maintenance with supporting local biodiversity. These practices not only enhance the health of native insect populations but also contribute to a more resilient and thriving garden ecosystem while gifting you extra time for apple picking, hiking, and pumpkin spice lattes.