New Castle County, DE Tree Protection: Tree Replacement Requirements (2026)

Tree replacement in New Castle County is a development-driven requirement under the UDC rather than a homeowner obligation. UDC Article 40 landscape and tree preservation sections require developers and commercial site plan applicants to meet canopy coverage and tree replacement standards when removing preserved trees. Typical ratios range from 1:1 for standard trees up to 2:1 or 3:1 for specimen trees (generally 24+ inch DBH) identified in the required tree preservation plan. Replacement trees must meet minimum size standards, typically 2 to 2.5 inch caliper at planting, and come from an approved species list favoring native and climate-adapted species (white oak, tulip poplar, red maple, serviceberry, river birch). Non-native invasives (Bradford pear, Norway maple) are prohibited. Where on-site replacement is not feasible due to space or environmental constraints, a fee-in-lieu can be paid to the county tree fund under UDC provisions and used for public tree planting projects along county roads, parks, and public facilities. A maintenance establishment period of 1 to 2 years is standard, requiring replacement of any trees that die. Individual homeowners removing trees on existing residential lots are not required by county code to replace them. HOAs often impose separate replacement rules.