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 spring & summer landscape maintenance practices!
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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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No-Mow May, Low-Mow Summer
Spring is a busy season for landscape maintenance and one of the best ways to support pollinators is to do less, or at least wait until May when pollinators have woken from overwintering (about when the soils have consistently reached 50F), which gives time for many of the critters that are overwintering (see fieldnote on overwintering) in the leaves and stems to emerge. It is typically safe to begin spring cleanup on May 1st. Once spring landscape care is underway, the following best practices should be followed:
Leave leaves and some bare ground
When mulching your garden, leave some patches of bare ground, ideally in areas with well-drained sandy soils (Frischie et al., 2021), to allow for ground nesting habitat. To support soil health, consider switching to composted leaf mulch or mulching the garden with leaves that fell nearby. Avoid using a leaf shredder. Inspect leaves throughout the year to keep an eye out for signs of common fungal diseases like anthracnose and black tar spot. Remove any leaves with noticeable signs of fungal diseases. Visit UMass Extensions Professional Disease Guide for help identifying signs of stress on your leaves. Using composted leaf mulch will improve soil slowly by providing a decomposing source of organic matter and nutrients (Naikwade, 2014), which can be especially beneficial for plants in urban conditions and help pollinator plantings continue to thrive.
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Figure 1: Adding Signage can signal that you leave the leaves to support pollinators. Photographed by Matthew Shepherd, The Xerces Society
Mow Less
Many urban landscapes consist of lawns, non-native plants, and mulched plant beds which are not rich habitats for pollinators. Typical landscaping practices like frequent mowing remove flowers (essential nectar and pollen sources). This reduces floral diversity and habitat quality (Lerman et al., 2023). Other common practices, such as leaf blowing, cutting perennials back in the fall, and applying bark mulch to plant beds, minimize how valuable these spaces are for pollinator nesting habitat in already-limited urban green areas.
If you have a lawn:
- Mow less often or mow less of your lawn.
- Skip mowing part (or all) of your lawn for the month of May (or beyond) and let your lawn develop some plant species diversity (yup, weeds) to help feed the pollinators.
- Starting in June, mow once every two weeks or less often.
- Do not mow from dusk to dawn.
- Set the mower at 3-4” height.
- Do not use pesticides.
- Consider overseeding a polyculture lawn mix (adding non-lawn species like yarrow or clover) to add biodiversity and floral resources to your lawn.
Lawn areas that do not need to be manicured for recreation or aesthetic purposes should be mowed less often or converted into habitat areas. In regularly mown lawns, allow the introduction of non-grass species (i.e., native flowering plants like violet, strawberry, and yarrow, or even common non-natives like clover) can contribute additional floral resources to support pollinators, especially in the early spring months when there are not as many options available. Massachusetts-based research has found that mowing every two weeks is the ideal frequency for supporting pollinators where lawns are required and poly-culture lawns (with small flowering plants) are preferred (Lerman et al., 2023). Mowing less provides the added benefit of reducing carbon emissions (or energy use), a goal outlined by the City of Somerville in the Climate Forward Plan. All mowing should occur during the day to limit impacts to insects (Owens, 2024), which is unfortunately the opposite of the EPA recommendation to mow in the evening to reduce formation of ground-level ozone (Osborne, 2018). Taking this all into account, mowing less space and less often (and with an electric mower) is the best option for pollinators and the climate.
Lawns should also be organically managed. Fewer applications of fertilizers will result in a slower-growing lawn with deeper roots, which is more drought tolerant. This kind of lawn will require less mowing and less watering to stay green.
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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.