This article appears in the Fall 2026 issue
Rethinking the Fall Cleanup
Understanding what native bees need could change your fall garden routine
Ah, the fall cleanup. It’s a welcomed shift in the duties of the avid gardener: time to put things to bed for the winter months ahead.
Lately I’ve been focusing on how my garden provides essential habitat for overwintering insects: the engines of pollination and healthy habitats. The more I’ve looked into the enabling “best housekeeping” practices, the more concentration it takes. It’s one thing to plant the native flowers that will provide food for pollinating insects, but it’s another thing to understand the complexities of how those insects live and what they need to raise their families and persist. That gets into the weeds, so to speak. It’s actually at the heart of why a messy- or “weedy”-looking garden is also the most favorable to sustain our pollinating insects—especially our native bees.
Coneflower (Echinacea purpurea) has hollow stems; seaside goldenrod (Solidago sempervirens) has pith-filled stems. Both are useful for our stem-nesting bees.
According to the Tufts University Pollinator Initiative, about 30 percent of New England’s native bees nest above ground. Some need hollow stems to situate their brood to overwinter and emerge in the spring. These are solitary bees that do not sting (unless provoked). The most common are leafcutter bees (Megachile spp.), Mason bees (Osmia spp.), and small carpenter bees (Ceratina spp.). They are an important component of effective pollination, a mechanism that goes on to feed many other animals in an ecosystem, including ourselves through the production of essential fruits and vegetables.
Leave overwintered stalks of perennials with hollow stems for use by stem-nesting bees. The stalks will be obscured by the new growing-season’s foliage.
Many of the plants that these bees use for their nests are probably familiar to you, including those with hollow stems, such as ironweed (Vernonia spp.), purple coneflower (Echinacea purpurea), swamp milkweed (Asclepias incarnata), bee balm (Monarda fistulosa), and mountain mint (Pycnanthemum muticum). They’ll also use pith-filled stems, excavating them to provide nesting chambers. These plants include sunflowers (Helianthus spp.), New England aster (Symphyotrichum novae-angliae), goldenrod (Solidago spp.), blazing star (Liatris spp.), Joe-Pye weed (Eutrochium spp.), and switchgrass (Panicum virgatum).
A sharp pruner will ensure that the opening is easy to find and access by the bees looking for a nest site.
The dead stems of these plants offer the chambers into which female bees will lay individual eggs from the late spring through midsummer, separated by a dividing membrane made from mud, leaves, or other available vegetation. Before closing up each nursery room, the single egg is provisioned with a nutritious ball of “bee bread”: pollen and nectar from the surrounding flowering plants, that will sustain the developing larvae through the winter months.
This is where you can make the difference. Wait until early spring to cut back the standing dead stems of your hollow and pith-filled perennials to varying heights from 8 to 24 inches, and leave them all summer, fall, and winter. These newly trimmed, as well as naturally occurring open stems, will provide the essential real estate the stem-nesting bees are seeking.
As the growing season progresses, new vegetation will envelope the standing cut stems from last year’s plants, providing both structure and protection from predators and the elements. Now plugged, the old stalks are harboring the next generation of bees. The new vegetation will not house stem-nesting bees until next spring.
Meanwhile, last season’s overwintering bee larvae will mature in the spring and, one by one, emerge from their bedrooms. The males are the first to surface. They mate with the females that follow and die shortly thereafter. The adult females will begin searching for available hollow or pith-filled stems, while foraging and providing pollinating services to the ecosystem.
Your deliberate stewardship in this way is one of those “best housekeeping practices” that goes beyond planting an attractive flower garden. It is working with, and for, nature for a shared positive outcome. That’s got to feel good, don’t you think?
There’s a second benefit come fall to leaving your stems with mature flower heads intact, which by now have ripened into seeds. That bounty can feed not only birds that migrate through your yard, but the resident winter chickadees, titmice, and finches (among others).
Joe-Pye weed (Eupatorium) is a robust native that produces abundant flowers, seeds, and hollow stalks making it ideal for stem-nesting bees.
Eventually the vacated stems that housed a new generation of spring bees will decompose, adding organic matter to the soil (always a good thing). I like to hasten that process by cutting spent stalks in place into smaller pieces. Or, removal at that point to your compost pile will not endanger the bees.
That now makes it a bit easier to understand why leaving the stalks—all the stalks from this season and last, sets you on your way to enhancing the annual availability of suitable nesting sites for these very important pollinating bees.
There is a middle ground. I will often preemptively cut some stalks in the fall to varying heights that are in danger of flopping down onto the pathways, or other plants. Alternatively, I will use readily available metal guide stakes, shaped like a half moon, to shore up dense vegetation. It’s a concession to neatness without losing the value of leaving stalks to overwinter.
If you’re still concerned about the messy appearance of overwintering stalks, consider getting a sign that declares your space as a pollinator garden. The Xerces Society, Wild Ones, and Pollinator Pathway all have educational signs available for just that purpose.
An intact garden in winter can provide its own kind of beauty and shelter overwintering bee larvae.
What gets to the heart of ecologically-minded garden practice is how to provide the necessary infrastructure through the seasons. It’s not just what you plant, but how willing you are to modify, or abandon altogether, garden etiquette in favor of inviting nature to your doorstep.
Judy Preston is a local ecologist active in the Connecticut River estuary. Her “Gardening for Good” column appears in each issue.