Cool Season Lawn Management Calendar

April 2017

Tall Fescue, Kentucky Bluegrass, Perennial Ryegrass MAINTENANCE CALENDAR

Note: X = Best time frame for indicated activity. Adjust based on uniqueness of each year and local needs.

Watering – Number equals projected water needed on a weekly basis if watering will be practiced. Try to reduce amount and frequency for water savings.

Mowing – Number listed is the cutting height for each mowing if using low to medium maintenance.

Fertilizing (F) – letter indicates optimum timing. Adjust the amount/timing on intended results.

White grub control – P = preventive insecticides; C = curative insecticides (see notes below).

Ninety percent tall fescue mixed with 10 percent Kentucky bluegrass is suggested. Perennial ryegrass is not suggested, but may be in some mixes. Use two or more improved tall fescues in the mix with one or more bluegrasses. Many good varieties are available.


New Lawn – Seed at label directed rate. 

Overseeding – Overseed at labeled rate or at ½ full “New Lawn” rate.

Best Time – Fall

Second Choice – Spring


Mow at 2.5 – 3”. Remove no more than 1/3 of the top growth at any one time. Recycle by removing the bagging attachment or use a mulching mower.


Keep soil moist during establishment. When mature, moisten to 4 – 6 inches soil depth.  Water mature grass when footprint impressions remain after walking over lawn. Adjust watering based on the needs of the lawn and rainfall that occurs and not a set schedule.


• Soil test every three years.

• Apply up to 1 lb. of actual nitrogen per 1,000 sq. ft. in late February or early March, either late April or very early May, late September, and mid to late November.

• Avoid fertilizing during the summer (June through August).

Pest Management – Scout lawns frequently. Identify pests. Use improved varieties. Adjust management practices. Record history of pest problems. Use pesticides only if needed. Read & follow label directions!


Preemergent Grass Control – (pick only 1, products with “**” are best), remember do not apply prior to seeding or laying sod). A second application may be needed, see labels for details.

  • dithiopyr** (DIMENSION®) – preemergent activity
  • pendamethalin** (SCOTT’S HALTS® and many others)
  • prodiamine** (BARRICADE®) – on fertilizer particle
  • oryzalin** (SURFLAN®)- if Kentucky bluegrass is present, consider another herbicide
  • oryzalin + benefin (XL 2G®**, AMAZE®) – if Kentucky bluegrass or perennial ryegrass are present consider another herbicide
  • siduron (TUPERSAN®) – use only if seeding in spring and in fescue, bluegrass or ryegrass only. TUPERSAN® is weak but is the only preemergent herbicide that can be used at seeding time on cool-season turfgrass.

Preemergent Broadleaf Control –


Postemergent Broadleaf Control –

WEED-B-GON®, TRIMEC®, Bayer Lawn Weed & Crabgrass Killer®, Spectracide Weed Stop For Lawns® or Ortho Weed–B-Gone Max plus Crabgrass Control®.

Postemergent Nutsedge Control –

halosulfuron-methyl ( SEDGEHAMMER®) – for yellow or purple nutsedge. bentazon (BASAGRAN®) – yellow nutsedge.

Grass Killer for Edging – (do not use these over the lawn)

  • glyphosate (ROUNDUP®, ROUNDUP PRO®, RANGER PRO®, HONCHO PLUS®,  KILLZALL®, and many more)
  • glufosinate-ammonium (FINALE®)
  • fluazifop-P-butyl (GRASS-B-GON®, OVER-THE-TOP GRASS KILLER®)
  • sethoxydim (SEGMENT®, ferti-lome® OVER-THE-TOP II GRASS KILLER, Grass Getter®) – for tall fescue control, not ryegrass or bluegrass control


Preventive (P): Products containing imidacloprid (Merit®, Bayer Advanced Seasonlong Grub Control®), clothianidin (Arena®, Green Light Grub Control with Arena®), chlorantraniliprole (Acelepryn®, Scott’s GrubEx®), or halofenozide (Natural Guard Grub Control, Spectracide® Grub Stop™). Apply preventative products in late April to mid-May, but only in areas with repeated history of grub problems.  Curative (C): Products containing trichlorfon (Dylox®, Bayer Advanced™ 24 Hour Grub Killer), or clothianidin (Arena®, Green Light Grub Control with Arena®) where grubs are known to be a current problem and found to be present. Apply in mid-August through mid-September.  Irrigate after application to activate the product. Not all lawns need white grub control applications.


Dennis Martin

Justin Moss 

Eric Rebek

David Hillock

DASNR Extension Research CASNR
OCES  Contact
139 Agricultural Hall
Oklahoma State University
Stillwater, OK 74078