How to Overseed Your Lawn Successfully (and Why TTTF is the Best Choice)

Why Overseeding is Important

Over time, lawns thin out. Heat stress, heavy foot traffic, and Oklahoma’s unpredictable weather can leave bare patches that weeds quickly invade. Overseeding fills those gaps with new grass seed, restoring density and improving the look and health of your yard.

In Oklahoma City and surrounding areas like Edmond, Norman, and Nichols Hills, we recommend overseeding every fall. This gives grass time to establish before winter and prepares it for a strong spring comeback.

Step 1: Timing Is Everything

The best time to overseed in Oklahoma is early to mid-fall, from September through early October. Temperatures are cooler, but the soil is still warm enough for germination. Overseeding in spring is possible, but weeds compete heavily and summer heat often kills new seedlings.

• Best time: September through early October.
• Too late: If soil temps drop below 55°F, seed won’t germinate properly. Overseeding after mid-October is risky because grass won’t have time to establish before winter.
• Spring overseeding: Possible, but less effective. Summer heat often kills young seedlings.

Step 2: Prep the Lawn

1. Mow short. Cut grass down to about 2 inches. Bag clippings so seed reaches the soil.
2. Aerate the soil. Oklahoma clay is compact, which blocks roots. Aeration removes plugs of soil and creates holes for seed.
   • Rent a core aerator at Home Depot or Lowe’s for about $90 a day.
   • Go over the lawn in two directions.
3. Rake. Break up thatch, smooth plugs, and expose soil.

Step 3: Spread the Seed

• Use a broadcast or drop spreader.
• Apply 5–7 pounds of Turf-Type Tall Fescue seed per 1,000 square feet.
• Spread in two passes, one north/south and one east/west, for even coverage.

Step 4: Fertilize and Water

1. Fertilizer. Apply a starter fertilizer high in phosphorus to encourage root growth.
2. Watering schedule:
   • Days 1–14: Water lightly 2–3 times per day for 5–10 minutes. Soil should stay damp but not soggy.
   • Days 14–30: Reduce to once a day, longer sessions (10–15 minutes).
   • After 30 days: Water every other day, deeper so roots grow down.
   • Once fully established (6–8 weeks): Water 1–2 times per week, one inch per session.

City variance: If you are overseeding an entire backyard, request a watering variance from Oklahoma City Utilities. This allows you to water daily during establishment, even if restrictions are in place.

Step 5: Mowing and Ongoing Care

• First mow when seedlings reach 3–4 inches tall.
• Keep mower blades sharp. Dull blades pull seedlings out.
• Stay off new grass until it’s well established.

Why Turf-Type Tall Fescue (TTTF) Beats Regular Tall Fescue

• Finer texture. TTTF looks softer and blends better with existing turf.
• Deeper roots. Handles drought better than regular tall fescue.
• Dark green color. Holds color longer into winter.
• Durability. Resists wear from pets and kids.
• Lower maintenance. Less prone to disease and less mowing than standard fescue.

What If You Want to Replace Bermuda With TTTF

Bermuda is aggressive and will take over unless removed completely. Here’s how to do it:

1. Spray Bermuda with a non-selective herbicide like glyphosate in late summer or cover the backyard with a black plastic tarp.
2. Wait 2–3 weeks, then spray any regrowth again.
3. Scalp mow to 1 inch and remove debris.
4. Aerate heavily to open soil.
5. Seed with TTTF at a higher rate, about 8–10 pounds per 1,000 square feet.
6. Follow the watering and care schedule listed above.
7. Get a city watering variance before starting so you can irrigate daily.

Overseeding Checklist

Before Overseeding

• Mow lawn to 2 inches
• Bag clippings and debris
• Rent a core aerator from Home Depot or Lowe’s
• Aerate in two directions
• Rake lightly to expose soil

Seeding

• Spread 5–7 pounds of TTTF per 1,000 sq ft
• Apply seed in two directions for even coverage
• Fertilize with a starter fertilizer

Watering

• Days 1–14: 2–3 light waterings daily, 5–10 minutes
• Days 14–30: Once daily, 10–15 minutes
• After 30 days: Every other day, deeper watering
• After 6–8 weeks: 1–2 times per week, one inch each

Aftercare

• First mow at 3–4 inches
• Keep blades sharp
• Limit foot traffic during establishment

If Converting From Bermuda

• Spray Bermuda twice with glyphosate, 2–3 weeks apart
• Scalp mow to 1 inch
• Aerate heavily
• Seed at 8–10 pounds per 1,000 sq ft
• Apply for city watering variance