Multnomah County, OR Landscaping Rules: Native Plants (2026)

Multnomah County does not mandate native plant landscaping, but the East Multnomah Soil and Water Conservation District (EMSWCD) runs a Native Plant Sale, provides landscape assistance, and offers the Backyard Habitat Certification Program in partnership with Portland Audubon. Portland City Code Title 11 (Trees) and the Stormwater Management Manual (SWMM) require use of native or adapted species for street trees, green street facilities, and private stormwater facilities (rain gardens, bioswales, ecoroofs). Portland's street tree list PCC 11.50.040 includes Pacific madrone, Oregon white oak, vine maple, and Douglas fir among preferred natives. Oregon's House Bill 2571 (2023) codified at ORS 94.776 prohibits HOAs from banning xeriscaping, drought-resistant landscaping, synthetic turf, or native plant gardens, with limited reasonable aesthetic restrictions. Oregon Department of Agriculture noxious weed program ODA-403 lists invasives like English ivy (class B), Armenian blackberry, and garlic mustard that may be required for removal. Metro Regional Government offers Nature in Neighborhoods grants for native plant restoration. Multnomah County's Climate Action Plan encourages pollinator gardens and references Oregon State University Extension native plant guides. Private wells and septic systems within 100 feet of riparian areas have additional native vegetation buffer requirements under Oregon DEQ rules OAR 340-071.