Grass Care in Fall: A Step-by-Step Guide

Fall is the make-or-break season for lawn care. What you do between September and early December can determine whether you greet spring with a thick, healthy lawn or a patchy mix of weeds and bare spots.

By tackling essential fall lawn care tasks now, like aerating, overseeding and applying the right fall fertilizer, you’ll strengthen grass roots, improve weed control and help your lawn store energy for winter. The payoff? A thicker, greener, healthier lawn that thrives in spring.

This guide outlines step-by-step fall lawn care, similar to what TruGreen specialists do, so you can move confidently through the season change to your final mow of the season. 

Your lawn’s needs depend on whether you’re caring for cool season grass (like Tall Fescue, Kentucky Bluegrass and Ryegrass) or warm season grass (like Bermudagrass, St. Augustine and Zoysia).

Cool Season Grasses thrive in 60-75°F weather. Early to mid-fall is prime time for core aeration, overseeding and applying fall fertilizer. These tasks encourage root growth and crowd out perennial weeds.

Warm Season Grasses slow down when soil dips below 70°F. Instead of heavy nitrogen, focus on weed control, soil moisture and mowing at the correct height. In southern regions (like Florida or Texas), light potassium applications boost stress tolerance without forcing weak late-season growth.

Not sure which grass you have? TruGreen can help you identify what type of grass you have. 

Summer traffic and heat leave behind compacted soil, which chokes out root growth. Aerating your lawn solves this by removing small plugs of soil, allowing water, oxygen and nutrients to penetrate deep into the root zone.

When to Aerate: The best time to aerate your lawn is in early to mid-fall when cool season grass is actively growing and can quickly fill in the holes. For warm season grass, aim for late spring into mid-summer.

Pro Tip: After aeration, spread a thin layer of compost or soil conditioner to enhance nutrient retention and promote healthier grass growth. 

What’s the Best Fertilizer for Fall?

Choose a blend high in nitrogen, like 24-0-12 or 20-5-10, for long-lasting root support on cool-season lawns. Avoid using nitrogen on warm-season grasses and opt for a Potash (Potassium) fertilizer application instead to help prepare the lawn for winter stress.

When Should I Stop Mowing?

Mow until growth slows or frost is frequent. Check out the mowing charts below to see the best height for your grass type.

Is Overseeding Worth It?

Absolutely. For cool-season lawns, grass seed fills bare spots, improves density and reduces weed growth in thin lawns.

Can I Apply a Pre-Emergent?

Yes, if you’re not overseeding. Apply 6-8 weeks before the first frost to control weeds like annual bluegrass and chickweed. This should be common practice for warm-season grass lawns.

Should I Mulch or Rake Leaves?

Mulch leaves into dime-sized pieces when thin and rake or bag thick layers to prevent suffocation.

Can I Fertilize My Lawn Twice in Fall?

Yes, many homeowners benefit from two applications: one in early fall for recovery and root growth and another in late fall (before the ground freezes) to prepare for winter.

How Do I Prevent Lawn Disease in Fall?

Avoid overwatering, rake away heavy fallen leaves and apply a preventive fungicide if your yard has a history of snow mold or brown patch.

What’s the Best Way to Improve Soil Quality?

After aeration, top-dress with compost to add organic matter, balance pH with lime if needed and follow up with a soil test every 2-3 years for adjustments.