Landscaping Rules in Snohomish County, WA (2026)
6 county-level rules, plus city-specific rules for 4 cities in Snohomish County, Washington.
Verified from official government sources
Tree Trimming
For new development, retained trees must be fenced at the drip line and not disturbed. Abutting owners may trim weeds, grass, brush and blackberries in the first 10 feet of an unopened right-of-way, but may not cut significant trees there.
Tree trimming and protection during clearing and in the right-of-way
Some RestrictionsSCC 13.10.050(7)
Trimming, pruning, or removal, by an abutting property owner, of weeds, grass, brush, blackberries and other similar vegetation located on the first 10 feet of an unopened deeded right-of-way abutting the property at issue; provided, that: Significant trees...are not removed.
Tree Removal & Heritage Trees
Retained or replacement significant trees on Snohomish County development sites cannot be removed unless a certified arborist certifies a hazard in writing. Any retained significant tree damaged or removed during development must be replaced three-for-one, plus a fine.
Significant tree removal restricted; 3-to-1 replacement
Some RestrictionsSCC 30.25.016(12)
Any significant trees identified in a landscape plan to be retained and subsequently damaged or removed during site development shall be replaced at a rate of three trees for each one damaged or removed significant tree. Failure to replace...shall be subject to a fine as determined under chapter 30.85 SCC.
Weed Ordinances
Snohomish County has no set grass-height limit for residential yards, but every property owner must eradicate Class A noxious weeds and control designated Class B and C noxious weeds under state law, enforced by the county Noxious Weed Control Board.
Weeds & Tall Grass Rules in Snohomish County
Some RestrictionsRCW 17.10.020(1)
In each county of the state there is created a noxious weed control board, bearing the name of the county within which it is located. The jurisdictional boundaries of each board are the boundaries of the county within which it is located.
Rainwater Harvesting
Snohomish County doesn't require rainwater harvesting, but it pays commercial property owners for it: install a qualifying rooftop system under SCC 25.10.040 and the county's surface water management service charge drops under SCC 25.20.070(4), scaled to how much of your roof runoff the system actually captures.
Rainwater Harvesting Cuts County Drainage Fees
Light RestrictionsSCC 25.10.040; SCC 25.20.070(4)
25.10.040 Commercial rainwater harvesting system. A system for storing, collecting, and reusing rainwater from a rooftop, installed at a commercial-use building, that has been designed and constructed in accordance with the Washington State Building Code Council's Permissive Rainwater Harvesting System Guidelines for Non-residential Occupancies (2002 or as amended), has a storage volume of at l...
Native Plants
New tree canopy planted to meet Snohomish County's development landscaping requirements can't be all one species. SCC 30.25.016(6) sets a minimum 50 percent evergreen mix, capped at 30 percent of any single species and 60 percent of any one taxonomic family, with a reduced evergreen share allowed when the deciduous portion is exclusively Puget Sound native species.
Native Species Planting Mix in Snohomish County
Some RestrictionsSCC 30.25.016(6)
(6) In addition to the requirements of SCC 30.25.015(5) through (7), trees planted to meet tree canopy requirements in SCC Table 30.25.016(3) shall meet the following criteria: (a) Sites must be planted or replanted with a minimum of 50 percent evergreen species, except: (i) The evergreen portion of the required planting mix may be reduced to 37.5 percent when the deciduous mix contains exclusi...
Artificial Turf
Snohomish County treats artificial turf as non-vegetative landscape material under SCC 30.25.015(3). It can help satisfy required site landscaping, but the county caps decorative, non-living features, turf included, at no more than 20 percent of the required perimeter and parking lot landscaping area, and it must be minimized, not used to replace living plant material wholesale.
Artificial Turf Rules in Snohomish County Landscaping
Some RestrictionsSCC 30.25.015(3)
Planting areas outside of the right-of-way may include landscape features such as decorative paving, sculptures, fountains, rock features, benches, picnic tables, and other amenities; provided that the area devoted to such features may count toward no more than 20 percent of the total required perimeter and parking lot landscaping area. Use of bark, mulch, gravel, and similar non-vegetative mat...
Landscaping Rules by City in Snohomish County
4 cities in Snohomish County have their own landscaping rules rules. Each link goes to that city's dedicated page with code citations.
5 verified rules • Native Plants, Tree Removal & Heritage Trees
6 verified rules • Native Plants, Rainwater Harvesting
6 verified rules • Composting, Native Plants
5 verified rules • Rainwater Harvesting, Tree Removal & Heritage Trees
All Snohomish County ordinances
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