Quick Answer
Start mowing your lawn in spring when grass reaches 3-4 inches tall and soil temperatures consistently stay above 40°F, typically occurring in late March to early May depending on your location[1]. Wait until the ground is firm enough to walk on without leaving footprints and your grass shows active green growth rather than dormant brown patches.
Key Takeaways
- Begin mowing when grass height reaches 3-4 inches and shows active growth
- Soil temperature should consistently stay above 40°F before first mow
- Ground must be firm and dry to prevent lawn damage from mower weight
- Cool-season grasses typically start growing 2-3 weeks earlier than warm-season varieties
- Never cut more than one-third of grass blade length in your first spring mowing
Spring lawn care sets the foundation for a healthy, vibrant yard throughout the growing season. Timing your first mow correctly prevents damage to emerging grass while encouraging strong root development and thick growth.
How Do I Know My Grass Is Ready for Spring Mowing?
Look for three key indicators before firing up your mower. First, check that your grass has reached 3-4 inches in height with visible green growth rather than dormant winter coloring[2]. Second, ensure soil temperatures have consistently remained above 40°F for at least a week - you can check this with a soil thermometer inserted 2 inches deep.
Finally, test ground firmness by walking across your lawn. If your feet leave deep impressions or the ground feels spongy, wait another week[3]. Mowing on soft, wet ground compacts soil and can damage grass roots permanently.
What Signs Should I Look for Before the First Mow?
Examine your lawn for active growth signals that indicate grass has emerged from winter dormancy. New green shoots appearing at the base of grass blades show your lawn is actively photosynthesizing and ready for cutting[1]. You'll notice the grass tips turning from brown or yellow to vibrant green.
Check for uniform growth across your entire lawn. Some areas may green up faster due to sun exposure, drainage, or microclimate differences[4]. Wait until at least 70% of your lawn shows active growth before mowing to avoid stressing dormant areas.
Inspect your mower and sharpen blades before the first cut. Dull blades tear grass rather than cutting cleanly, creating brown, frayed tips that invite disease[2].
How Does Grass Type Affect Spring Mowing Timing?
Cool-season grasses like fescue, bluegrass, and ryegrass begin active growth when soil temperatures reach 40-45°F, typically in late March to mid-April in most regions[5]. These varieties can handle earlier mowing since they thrive in cooler spring conditions.
Warm-season grasses including Bermuda, Zoysia, and St. Augustine remain dormant until soil temperatures consistently reach 65-70°F[3]. Don't rush to mow these varieties - premature cutting can damage crowns and delay green-up by several weeks.
In transitional climate zones, you might have both grass types in your lawn. Focus on the dominant variety when timing your first mow, but use a higher cutting height to accommodate any slower-developing areas.
What's the Best Approach for Your First Spring Mow?
Set your mower to its highest setting for the first spring cut, removing only the top third of grass blades even if your lawn looks shaggy[2]. This conservative approach protects grass crowns and encourages deep root development essential for summer stress tolerance.
Choose a dry, mild day for your first mow when temperatures are between 50-70°F. Avoid cutting during the hottest part of the day or when grass is wet from dew or recent rain[4]. Wet grass clumps together, creating uneven cuts and potentially clogging your mower.
Mow in a different pattern than your last fall cutting to prevent soil compaction and encourage upright grass growth. If you ended the season mowing north-south, start spring by mowing east-west[1].
Conclusion
Timing your first spring mow correctly sets your lawn up for success throughout the growing season. Wait for consistent soil temperatures above 40°F, grass height of 3-4 inches, and firm ground conditions before beginning. Remember to cut high, keep blades sharp, and adjust timing based on your specific grass type. Your patience in spring will reward you with a healthier, more resilient lawn all summer long.
Sources
- Michigan State University Extension - Spring lawn care and mowing guidelines
2. University of Minnesota Extension - Turfgrass management and seasonal care practices
3. Pennington Seed Research - Grass growth patterns and mowing best practices
4. Texas A&M AgriLife Extension - Warm and cool-season grass management
5. University of Georgia Extension - Soil temperature monitoring and lawn care timing