Somerville, MA Landscaping Rules: Native Plants (2026)

Article X of chapter 12, adopted by Ordinance 2021-05 effective March 25, 2021, sets "minimum standards for the use of native vegetation by the city" to support species conservation and ecological restoration. Section 12-175 limits its own reach: the ordinance "shall only apply to all new trees and other plants planted by the city, or by a third-party on behalf of the city," and existing plantings are unaffected, meaning private homeowners face no native-planting mandate on their own yards. Where it does apply, section 12-176 flatly bars invasive species from any city planting, and section 12-177 requires 100 percent native plants in riparian areas, the community path, and the Green Line Extension rail corridor, at least 75 percent native plants in city parks each year, and at least 50 percent native street trees each year, though the city may use up to 50 percent non-native, non-invasive plants in bioswales, plazas, streetscapes and other city-owned property when flexibility is needed for memorialization, aesthetics or survivability.

Community gardens, volunteer bulb plantings, lawns and athletic fields, holiday plantings and green roofs are allowed to skip native requirements while still being encouraged to include native species. Section 12-178 requires the city to avoid neonicotinoid-treated native plants where reasonably available, and bars sourcing them entirely starting January 1, 2028. The director of public space and urban forestry must publish an annual report by December 31 listing plantings by area and the share that were native, forwarded to the city council and urban forestry committee.