Colorado Lawn Mowing Calendar
Published: February 1, 2026 · Updated:
Colorado's semi-arid climate, high altitude, alkaline soils, and intense UV radiation create lawn conditions unlike anywhere east of the Rockies. Kentucky Bluegrass remains the dominant grass despite its water requirements, with Buffalo Grass and Tall Fescue increasingly popular as water costs rise.
Best Mowing Heights for Colorado Lawns
Kentucky Bluegrass
Ideal: 63mm (2.5")
Summer: 90mm (3.5")
Never below: 38mm
Mow every: 7 days (peak)
Tall Fescue
Ideal: 75mm (3.0")
Summer: 90mm (3.5")
Never below: 50mm
Mow every: 7 days (peak)
Zoysia Grass
Ideal: 38mm (1.5")
Summer: 45mm (1.8")
Never below: 13mm
Mow every: 14 days (peak)
Colorado Monthly Mowing Schedule
Based on Kentucky Bluegrass in zone 6b.
Mowing Tips for Colorado
The transition zone (zones 6–7) requires adjusting mowing height dramatically between seasons. Summer height should be 25–40mm higher than spring.
If you have Tall Fescue, maintain at 90mm through summer. This is higher than most guides suggest but critical for heat tolerance.
Never scalp warm-season grasses in fall transition. Leave at least 50mm to protect crowns entering dormancy.
What Makes Mowing in Colorado Different
Mowing in Colorado is inseparable from irrigation — the state's 12-15 inches of annual precipitation is insufficient for traditional lawn grass without supplementation, and water rates in Denver, Colorado Springs, and Boulder have risen significantly over the past decade. Kentucky Bluegrass needs approximately 25-30 inches of supplemental water per year to remain green through Colorado's hot, dry summers, and many homeowners have accepted partial summer dormancy rather than continue full irrigation. Raising mowing height to 90mm in May and maintaining it through August reduces water requirements by 25-30 percent while keeping the lawn visually acceptable; allowing the grass to go dormant in July heat further reduces consumption without permanent damage. Colorado's intense UV radiation at elevation causes cut grass surfaces to bleach and desiccate within hours; morning mowing and sharp blades are particularly important. The state's alkaline soils (pH 7.5-8.0 in most residential areas) make iron chlorosis a near-universal issue in Kentucky Bluegrass, producing the pale yellow-green color that homeowners often misidentify as nitrogen deficiency. Chelated iron applications in spring and maintaining consistent moisture are the practical responses. Colorado's hail season from May through August can flatten mature grass and require careful recovery mowing — never immediately scalp damaged grass, instead raise the cutting height by 15mm for two to three mowings to allow recovery. Buffalo Grass is an emerging alternative in drier areas, requiring roughly 40 percent of Bluegrass's water use and mowing only monthly at 75-100mm.
Colorado Cities
Frequently Asked Questions
When should I start mowing my lawn in Colorado?
Start mowing in Colorado when grass shows active green growth and soil temperature exceeds 10°C. For zone 6b, this is typically March–April. Set mower at maximum height for the first 2–3 cuts.
What height should I mow Kentucky Bluegrass in Colorado?
Kentucky Bluegrass in Colorado should be maintained at 63mm during spring and fall, raised to 90mm in summer. Never cut below 38mm.
How often should I mow my lawn in Colorado in summer?
In Colorado's zone 6b climate, Kentucky Bluegrass typically needs mowing every 7–14 days in peak summer. If growth slows in heat, extend the interval.
When should I stop mowing my Colorado lawn in fall?
Cool-season grasses in Colorado can be mowed until the ground freezes — typically November. Final mow at 65mm.
Should I raise my mowing height in Colorado summers?
Yes — raising mowing height by 15–25mm in summer is one of the most important adjustments for Colorado lawns. Taller grass shades roots, retains soil moisture, and reduces heat stress. This applies to all grass types.