Jefferson County, MO Landscaping Rules: Tree Trimming (2026)

2600, Visual Clearance Standards - Minimum Sight Distance, requires proper lines of sight to be maintained at all intersections and driveways in the unincorporated county. Within the sight triangle, no building or other visual obstruction may be placed, erected, or maintained. Street trees and certain vegetation, poles, and posts are allowed inside the triangle only if they carry no foliage, limbs, or other obstruction between 3 and 10 feet above ground level, are no more than 15 inches in trunk diameter, and stand no closer than 35 feet to the intersecting pavement edge; decorative fences are allowed on the same 35-foot offset provided their design keeps a clear view through the clearance area.

2600(B)(2)(c) as the space formed by lines 35 feet long along the pavement edges of intersecting streets, or a driveway and a street right-of-way, measured from their point of intersection; within it, no landscaping, screening material, sign, parked vehicle, or other object may interfere with the sight line between 3 and 10 feet above the pavement. At roundabouts the clear-vision area extends 25 feet from the outside curve's pavement edge. 2600(A) requires the sight lines to be maintained on an ongoing basis, not just at the time of construction, which means a property owner whose tree or hedge grows into the triangle after occupancy remains responsible for keeping it trimmed to the standard.