Welcome to our Pollinator Field Note Series! Offshoots released a Pollinator Action Plan with the City of Somerville, in collaboration with bee scientist and expert Nick Dorian. Continue reading to take a sneak peek into our conversation about fall maintenance and overwintering practices!
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Fall Maintenance & Overwintering Practices
Pollinators are essential to ecosystems and food production, yet their populations are declining due to habitat loss, pesticide use, invasive species, light pollution, and climate change. Urban development and agricultural expansion have fragmented once-diverse landscapes, replacing them with lawns and non-native plants that offer little value to pollinators.
These animals rely on connected habitats for nectar, pollen, nesting materials, and host plants, often traveling hundreds of yards or more to find resources. Ensuring connectivity between habitat patches is critical for their survival.
Pollinator gardens in urban areas can help restore these connections while also engaging communities. When people appreciate and interact with pollinator-friendly spaces, they are more likely to support conservation efforts—creating a cycle that benefits both pollinators and people.
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Fall is often a busy time for lawn and garden maintenance when practices center around preparing the landscape for winter. A widely accepted convention is to rake up leaves, cut perennials down to the ground, and bag up all the dead plant material to be sent off and composted off-site. This process misses the opportunity to renew existing soils with beneficial nutrients and create nesting and overwintering habitats for pollinators. The following small tweaks to the fall cleanup process are best practices for promoting pollinator habitat:
Leave the leaves
Instead of raking up all the leaves, it is best practice to leave at least some leaf litter where it lands or mulch your garden beds with it to support overwintering and nesting pollinators. Walkways, patios, and other hardscape areas should be kept clear of leaves to reduce potential hazards, but these leaves can be moved into nearby planting beds. Avoid using a leaf shredder when possible as insects or their offspring may be a casualty. Using whole leaves from the site is the most beneficial for soil and wildlife, but it is still better to shred leaves on site than removing them entirely.
Leaving leaves below tree and shrub species can provide “soft landings” to help butterflies and moths complete their life cycles (Holm, 2024). Leave some bare ground in 2-foot diameter patches for ground nesting bees. For more information on leaving the leaves, check out the Fall Neatening Guide developed by the Somerville Urban Forestry Committee.
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Figure 1: Pithy Stems, Photographed by Nelle Ward, Offshoots
Keep perennial stalks, sticks, and dead wood
Rather than cutting perennials down to the ground, allow herbaceous plants to remain overwinter at their full height (this is beneficial for wildlife habitat and for seed dispersal and native plant reproduction). Where cutting is necessary, leave some dead pithy stems standing (pithy stems have spongy cell tissue in the center like raspberries or hydrangeas), by cutting any hollow/open stemmed plants, (such as iris flower stalks) to 6-18” height to provide potential bee nesting sites. These stalks should be left in place for 2 years to allow a complete nesting cycle. Each new season’s growth will cover up the old growth, so dead stems will be hidden once the garden grows in. Consider keeping a pile of woody debris (stems, branches) somewhere on site, as these can provide beneficial nesting sites for beetles, flies, and bees. Where grass and forb (herbaceous flowering plant) meadows are installed, keep plants at full height through the winter and only cut one time per year annually in late March. The texture of these plants can create a beautiful winter landscape to extend the beauty of the garden.
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This research was a part of Offshoots’ research project in partnership with the City of Somerville and field scientist Nick Dorian, to create the Somerville Pollinator Action Plan (SPAP). Citations and links to academic articles can be found in the SPAP document. To learn more about the action plan, visit our SPAP projects page here.