Washington County, OR Tree Protection: Tree Replacement Requirements (2026)

Mitigation planting requirements tie to the respective city tree codes. Beaverton BC 9.04 and BDC 60.60 require replacement at 1:1 for removals up to 12-inch DBH, escalating to 2:1 or 3:1 for larger specimens and heritage trees. Replacement caliper minimum: 1.5-2 inches for deciduous, 6-8 ft height for conifers. Hillsboro CDC 12.32 similar ratios with approved species from the Hillsboro Street Tree List (heavy on Oregon white oak, madrone, vine maple, Douglas fir, western red cedar for natives). Tigard Urban Forestry Manual specifies detailed planting standards including staking, mulching, and two-year maintenance bond. Tualatin TDC 73.400 and Forest Grove FGMC 6.28 adopt similar frameworks. Cornelius, Sherwood, and North Plains have lighter standards. Washington County's CDC §422 mitigation applies primarily to Significant Natural Resource and Habitat Friendly Development areas. Fee-in-lieu options fund the Beaverton Tree Fund, Hillsboro Tree Fund, and Tigard Urban Forestry Fund for plantings in public right-of-way. Non-native species generally disallowed; invasive species (English ivy, holly, cherry laurel) never acceptable. Maintenance period 1-2 years with replacement obligation if mortality occurs.