On Monday, September 22nd, the autumnal equinox marks the official start date of autumn. The date always seems to sneak up on us, so we want to share 11 tips on fall lawn prep to get you prepared.
1. Rake Often
Boise’s oak, maple, and ash leaves may look beautiful, but when left on the ground, they block sunlight, oxygen, water, and nutrients from your lawn. Rake every three to four days to prevent disease, pest buildup, thatchy accumulation and soil compaction. Instead of bagging and tossing them, consider composting your leaves or mowing them into your lawn to enrich it when spring arrives.
2. Keep Watering Until Freeze
Even as nights cool off, your lawn still needs moisture. Aim for 1–2 inches of water weekly, either in one dose or split into two, just don’t water more than twice a week to avoid shallow root growth. Water before 10 a.m. to reduce evaporation and disease risks. Stop watering once temperatures consistently stay below 40 °F, typically by mid to late October in Boise, or after a hard freeze.
3. Dethatch If Needed
If your lawn feels spongy or the thatch layer exceeds half an inch, it’s time to dethatch. This removes excess dead material that blocks essential nutrients. Use tools like a manual dethatcher or power rake, choosing timing carefully like mid- to late September gives grass time to recover before frost.
4. Aerate Annually
Aerating (removing small soil plugs) helps water, air, and nutrients reach roots more easily, promoting healthier, stronger growth heading into winter and beyond.
5. Overseed Before Frost
Patchy lawn? Fall is prime time for overseeding. Spread seed, preferably tall fine fescue, Kentucky bluegrass, or ryegrass to fill in sparse areas. Cooler temperatures and moist soil make for successful germination.
6. Consider a Soil Test
If you suspect nutrient imbalances or odd growth behavior, a soil test can reveal what your lawn needs from lime, nutrients, or organic amendments to flourish in spring.
7. Winterize Your Sprinklers
To prevent burst pipes or damaged components, drain and winterize your irrigation system before freezing conditions arrive.
8. Fertilize for Strong Roots
Apply a fall-specific fertilizer, often referred to as a “winterizer”, to support root growth and resilience through winter, setting your grass up for a healthy spring return.
9. Tackle Weeds with Post-Emergent Herbicide
Fall is the perfect time to apply weed control before weeds go dormant. Target them now to weaken them before winter and reduce spring regrowth.
10. Mow Until Growth Halts
Continue mowing until the grass stops growing, typically once temperatures remain under 40 °F. Keep the mowing height consistent with the season; the final cut signals your yard’s readiness for dormancy.
11. Put Gardens to Bed
Clear out annual plants and tidy up perennial beds. Clean, mulch and prepare garden areas now to protect plants and make spring planting smoother.
With these steps, your Treasure Valley lawn will be well-positioned to emerge healthy and refreshed next spring.