Idaho Lawn Care Calendar: Month-by-Month Guide for 2025
Keeping your Treasure Valley lawn healthy requires different care throughout the year. This comprehensive calendar tells you exactly what to do each month for a beautiful lawn in Boise, Meridian, Nampa, Eagle, and surrounding Idaho communities.
Quick Reference: Idaho Lawn Care by Season
| Season | Key Tasks | Priority Level |
|---|---|---|
| Winter (Dec-Feb) | Snow removal, equipment prep | Low activity |
| Early Spring (Mar-Apr) | Pre-emergent, first mowing, cleanup | High |
| Late Spring (May) | Regular mowing, fertilization | High |
| Summer (Jun-Aug) | Irrigation management, mowing | Moderate |
| Fall (Sep-Nov) | Aeration, winterizing, final prep | High |
January: Planning Season
What Your Lawn Is Doing: Dormant under snow or frost. No active growth.
Tasks This Month:
- ✅ Sharpen mower blades – Dull blades tear grass, causing brown tips
- ✅ Service mower – Change oil, replace spark plug, check belts
- ✅ Review last year – What worked? What problems occurred?
- ✅ Schedule sprinkler startup – Book now for April service
- ✅ Clear debris – Remove branches, trash, and anything that can smother grass
Don’t:
- ❌ Walk on frozen grass (damages crowns)
- ❌ Apply any fertilizer or treatments
- ❌ Start watering—irrigation should be off
February: Pre-Season Prep
What Your Lawn Is Doing: Still dormant, but soil is beginning to thaw on warm days.
Tasks This Month:
- ✅ Test irrigation controller – Check programming and battery
- ✅ Inspect sprinkler heads – Look for damage from winter
- ✅ Order supplies – Fertilizer, seed for bare spots, pre-emergent
- ✅ Check for vole damage – Look for surface tunnels in snow cover
Weather Watch:
- Late February often brings “false spring” in Boise
- Don’t be fooled—more freezing weather is coming
- Soil temps are typically 35-45°F
March: Spring Awakening
What Your Lawn Is Doing: Beginning to green up. First signs of growth appearing.
Tasks This Month:
- ✅ Apply pre-emergent (March 1-15) – Before soil hits 55°F consistently
- ✅ Spring cleanup – Rake dead material, remove leaves
- ✅ First fertilization – Low-nitrogen, starter formula
- ✅ Soil test (optional) – Identify pH and nutrient deficiencies
- ✅ Repair bare spots – Overseed early for best results
Mowing:
- First mow typically mid-to-late March
- Set height at 3.5” (taller than summer)
- Only remove 1/3 of blade height
Pro Tip:
Pre-emergent timing is critical. In Boise, this usually means the first two weeks of March. Too late and crabgrass will germinate; too early and it breaks down before it’s effective.
April: Active Growth Begins
What Your Lawn Is Doing: Rapid growth phase. Grass is actively producing new shoots.
Tasks This Month:
- ✅ Sprinkler startup – Have system activated and tested
- ✅ Begin regular mowing – Weekly during rapid growth
- ✅ Second fertilization (late April) – Balanced formula
- ✅ Post-emergent weed control – Spot-treat broadleaf weeds
- ✅ Adjust irrigation – Begin spring watering schedule
Mowing:
- Frequency: Every 5-7 days
- Height: 3-3.5 inches
- Pattern: Vary direction each week
Irrigation Schedule:
- Start with 2-3 days per week
- Water early morning (5-7 AM)
- 20-30 minutes per zone
May: Peak Spring Growth
What Your Lawn Is Doing: Maximum growth rate. This is the lawn’s most vigorous period.
Tasks This Month:
- ✅ Maintain mowing schedule – May need twice weekly in rapid growth
- ✅ Monitor irrigation – Increase as temperatures rise
- ✅ Watch for grubs – Brown patches that pull up easily indicate infestation
- ✅ Edge and trim – Keep clean lines along beds and walks
Mowing:
- Frequency: Every 4-5 days if growing rapidly
- Lower height to 3 inches as weather warms
- Never remove more than 1/3 of blade
Weed Watch:
- Dandelions peak in May
- Address quickly before they seed
- Spot spray or hand-pull small infestations
June: Summer Transition
What Your Lawn Is Doing: Growth slowing as temperatures increase. Shifting into heat stress mode.
Tasks This Month:
- ✅ Early summer fertilization (first week) – Slow-release formula only
- ✅ Increase irrigation – Move to every-other-day schedule
- ✅ Check for insect damage – Billbugs become active
- ✅ Raise mower height – Back to 3.5” to shade roots
Irrigation Schedule:
- 3-4 days per week
- Deeper, less frequent watering
- Early morning only (before 8 AM)
Heat Preparation:
As temperatures approach 90°F:
- Avoid mowing during hottest part of day
- Keep blades sharp to minimize stress
- Consider leaving clippings to return moisture
July: Heat Stress Management
What Your Lawn Is Doing: Slowing growth significantly. Possible temporary dormancy during extreme heat.
Tasks This Month:
- ✅ Mid-summer fertilization (July 15-30) – Light application, iron supplement
- ✅ Monitor for drought stress – Footprints that don’t spring back
- ✅ Maintain irrigation schedule – Consistent deep watering
- ✅ Mow high – 3.5-4 inches to shade soil
Heat Advisory:
When temperatures exceed 100°F:
- Consider skipping fertilization
- Allow lawn to go semi-dormant if necessary
- Don’t panic about brown color—it will recover in fall
Irrigation Tips:
- Water deeply 2-3 times per week
- Each zone: 30-45 minutes
- Check for dry spots and adjust heads
August: Late Summer Survival
What Your Lawn Is Doing: Minimal growth. Focusing energy on root survival, not top growth.
Tasks This Month:
- ✅ Continue deep watering – Don’t reduce until temperatures drop
- ✅ Plan fall aeration – Schedule for September
- ✅ Scout for disease – Brown patch can appear in humid conditions
- ✅ Sharpen mower blades – Mid-season sharpening keeps cuts clean
Mowing:
- Frequency: Every 7-10 days (growth is slow)
- Height: Maintain 3.5-4 inches
- Morning only to avoid heat stress
Looking Ahead:
Start thinking about fall renovation:
- Order seed for overseeding
- Schedule aeration
- Plan fertilization schedule
September: Fall Recovery
What Your Lawn Is Doing: Second growth spurt as temperatures cool. Root growth is especially active.
Tasks This Month:
- ✅ Core aeration – Best time of year for this essential task
- ✅ Overseed thin areas – Ideal germination conditions
- ✅ Fall fertilization (early September) – High nitrogen for recovery
- ✅ Reduce irrigation – Temperatures are dropping
Aeration Benefits:
- Relieves soil compaction
- Improves water penetration
- Enhances root development
- Best done before overseeding
Mowing:
- Resume normal weekly schedule
- Gradually lower height to 3 inches
- Continue until growth stops (usually late October)
October: Winterization
What Your Lawn Is Doing: Slowing growth, storing energy in roots for winter.
Tasks This Month:
- ✅ Winterizer fertilization (Oct 15-Nov 1) – Final and most important application
- ✅ Sprinkler blowout – Before first freeze (typically late October)
- ✅ Final mowing – Lower to 2.5-3 inches for winter
- ✅ Leaf removal – Don’t let leaves smother grass
Sprinkler Blowout:
- Schedule professional blowout
- Must be done before ground freezes
- Prevents costly pipe and head damage
Winterizer Timing:
- Apply 2-3 weeks before ground freezes
- Boise area: usually October 15-25
- This application determines spring green-up quality
November: Final Prep
What Your Lawn Is Doing: Going dormant. Last bit of root activity before winter.
Tasks This Month:
- ✅ Final leaf cleanup – Remove all debris
- ✅ Store equipment – Clean mower, drain fuel or add stabilizer
- ✅ Clean up irrigation – Ensure all valves are properly drained
- ✅ Mark sprinkler heads – Helps avoid damage during snow removal
Don’t:
- ❌ Apply fertilizer after ground freezes
- ❌ Leave hoses connected
- ❌ Forget to shut off backflow preventer
December: Winter Dormancy
What Your Lawn Is Doing: Fully dormant. Crown and roots are alive but inactive.
Tasks This Month:
- ✅ Snow removal – Keep paths clear, but don’t damage grass
- ✅ Limit foot traffic – Frozen grass is fragile
- ✅ Monitor for ice damage – Ice sheets can suffocate grass
- ✅ Plan for next year – Review successes and challenges
Snow Tips:
- Use calcium chloride near lawn edges (less damaging than rock salt)
- Don’t pile snow on lawn areas you want to thrive
- Mark underground sprinkler components before first snow
Get Professional Help
Managing a lawn year-round takes significant time and knowledge. Our subscription service handles everything on this calendar automatically:
Complete Plan ($199/month) includes:
- Weekly mowing (April-October)
- 7 fertilization treatments at optimal timing
- Sprinkler blowout and startup
- Spider barrier treatment
- Snow removal (up to 3 times)
Questions about lawn care timing? Call us at (208) 504-0843—we’re happy to help plan your lawn care calendar.