Landscaping Rules in Thornton, CO (2026)
5 verified landscaping rules for Thornton, Colorado, sourced directly from the municipal code and official government pages.
Verified from official government sources
Tree Trimming
Thornton adopted Model Traffic Code Section 114 as local law through Section 38-523: property owners must trim or remove, at their own expense, any tree limb, shrub, vine, or hedge that projects over the public right-of-way and blocks a driver's view, hides a traffic sign, or otherwise creates a hazard for drivers or pedestrians.
Thornton Requires Owners to Trim Street-View Trees
Some RestrictionsThornton City Code § 38-523 (MTC § 114)
114. Removal of traffic hazards. (1)The owner of real property abutting or on the right-of-way of any highway, sidewalk, or other public way shall trim or remove, at the expense of said property owner, any tree limb or any shrub, vine, hedge, or other plant which projects beyond the property line of such owner onto or over the public right-of-way and thereby obstructs the view of traffic, obscu...
Tree Removal & Heritage Trees
Thornton does not require a homeowner permit to remove a healthy tree, but the city forester can order removal of any tree or plant, public or private, that spreads disease or insects or threatens public health and safety, and can bill the owner if they refuse.
Thornton Tree Removal Authority
Some RestrictionsThornton City Code § 46-102
The director or designee shall appoint the city forester. The city forester shall have such duties and responsibilities as assigned by the director or designee. The city forester shall also have the authority to order the removal of any trees or plants upon public or private property when the city forester determines such action is necessary to prevent the spread of disease or insects, and to p...
Weed Ordinances
Thornton bars property owners and lessees from letting weeds and brush grow past eight inches, with limited exceptions for large lots and specific zoning districts. Owners get 10 calendar days after written notice to cut, or the city can enter, clear the property, and bill the cost under § 38-444.
Thornton Eight-Inch Weed and Brush Height Limit
Some RestrictionsThornton City Code § 38-444(a)
(a)It shall be unlawful for a property owner or lessee to permit weeds and brush to grow to a height exceeding eight inches, for the purposes of this Section 38-444, property owner shall include any occupant or person in possession of the property. Excluded from the prohibitions of this subsection (a) are the following:(1)In Agricultural Districts, weeds other than noxious weeds shall be contro...
Water Restrictions
From April 1 through October 31, Thornton limits turf watering to three days a week chosen by the customer, with no irrigation between 10 a.m. and 6 p.m. New sod and seed get temporary exceptions, and large turf areas like parks and golf courses can water as needed if best practices are followed.
Thornton's Outdoor Watering Day Limits
Some RestrictionsThornton, CO Code of Ordinances § 74-58(b)(1)
Sec. 74-58. - Wise water use. (b)(1) Outdoor irrigation rules... a. Turf. Turf may be watered not more than three days per week, selected at the customer's discretion. Turf shall not be watered between 10:00 a.m. and 6:00 p.m., except for very short periods of time to adjust or repair an irrigation system. b. Turf seed or sod. Newly planted turf seed or sod may be watered as needed and appropri...
Native Plants
Thornton may encourage or require native and drought-tolerant landscaping. Some areas restrict traditional grass lawns in favor of water-efficient alternatives.
Thornton Native Plant & Xeriscape Rules
Few RestrictionsColo. SB23-178 (Water-Wise Landscaping)
Bill Summary: Under current law, a unit owners' association (association) of a common interest community may not prohibit the use of xeriscape, nonvegetative turf grass, or drought-tolerant vegetative landscapes to provide ground covering to property for which a unit owner is responsible. There is, however, an exception authorizing an association to adopt and enforce design or aesthetic guideli...
Looking for Adams County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Thornton city rules.
Landscaping Rules in Adams County →