Cool Season Lawn Calendar—Western Nebraska

Sarah Browning, University of Nebraska Extension Educator

John Fech, University of Nebraska Extension Educator

Amanda Folck, University of Nebraska Turfgrass Extension Educator, Agronomy and Horticulture

Roch Gaussoin, University of Nebraska Turfgrass Extension Specialist, Agronomy and Horticulture

A complicating factor in today’s garden market is turfgrass fertilizers and preemergence weed control products are often available only as combined products. Newer (less than 20 years old) and older lawns should be managed differently for resource efficiency and environmental stewardship. This publication provides timely information for Kentucky bluegrass, tall fescue and other cool season grasses (perennial ryegrass and fine fescues).

Newer lawns often struggle due to soil low in nutritional value and high weed pressure. They are best managed by making a fertilizer plus preemergence herbicide application in late April/early May followed by a second application in early June.

Older lawns need less fertilization to perform well and have lower weed pressure. Preemergence weed control plus fertilizer applications are optional based on need and desired outcome.


Proper Lawn Aeration—https://bit.ly/CSUaeration

Bluegrass Billbugs—https://bit.ly/UMNbillbug

Managing Billbugs in Turfgrass—https://bit.ly/PUbillbug

Broadleaf Weed Control—https://go.unl.edu/NEbroadleafweed

Brown Patch—https://byf.unl.edu/brown-patch

Crabgrass Control—https://go.unl.edu/NEcrabgrass

Establishing Lawns from Seed—https://go.unl.edu/NEturf-seed

Improving Turf in Fall—https://go.unl.edu/NEturf-fall

Irrigation Audit—https://go.unl.edu/NEirrigation-audit

Summer Patch—https://bit.ly/PSUsummer-patch

White Grubs—https://bit.ly/PUwhite-grub

This publication has been peer reviewed.

Nebraska Extension publications are available online at http://extensionpubs.unl.edu/.

Extension is a Division of the Institute of Agriculture and Natural Resources at the University of Nebraska–Lincoln cooperating with the Counties and the United States Department of Agriculture.

Nebraska Extension educational programs abide with the nondiscrimination policies of the University of Nebraska–Lincoln and the United States Department of Agriculture.

© 2023, The Board of Regents of the University of Nebraska on behalf of the Nebraska Extension. All rights reserve.



Cultural Practices

Pest Control


Newer Lawn

Older Lawn


Begin mowing as needed.

Mow at 3–3.5 inches all summer. Avoid removing more than 1/3 leaf height at one time.

May 1–10

0.75—1 lbs. N/1000 sq.ft.

0 Optional–

0.25 lbs. N/1000 sq.ft

Aerate 1

Summer patch prevention2

Billbugs 3

Annual weed preemergence control—1st application 4

0 If turf characteristics, such as color and density, are not ideal in early season, fertilizer can be applied. Otherwise, it can be skipped.

1 Use hollow tines for maximum compaction reduction.

2 When 2-inch soil depth reaches 65F temp., apply fungicides to lawns with history of infection. Repeat application 4 weeks later.

3 Only needed if lawn has a history of billbug damage. Look for adult feeding symptoms or activity in full sun near sidewalks.

4 When a 4-inch soil depth reaches 55F temp, apply fertilizer plus preemergence herbicide for annual weed control, including crabgrass and foxtail.

April 25-May 15


5 Core aerify before or power rake after seeding for good seed-soil contact. With new seedings, use only a preemergent containing mesotrione or topramezone to prevent seedling death.

June 10–20

0.5 lbs. N/1000 sq.ft.

0.5 lbs. N/1000 sq.ft.

Annual weed preemergence control—2nd application


Irrigate to prevent drought stress.

Irrigation/sprinkler audit 6

Scout for dollar spot and brown patch 7

6 Check uniformity of sprinkler output and equipment function. Turf requires 1” water/week for good growth, including both rain and irrigation. Overwatering weakens the turf.

7 Fungicides are not usually recommended for home lawns except in extreme cases.

June 25-July 4

White grub control

Apply preventive insecticides if lawn has a history of white grub damage.

Aug. 15-Sept. 5


Aug. 25-Sept. 15

0.75—1 lbs. N/1000 sq.ft.

Aug 20-Sept 30

Winter annual weed control

For lawns with a history of winter annual weeds, such as henbit and annual bluegrass, apply a fall preemergence herbicide to kill germinating seeds.

Sept 1–15

0.5–1 lbs. N/1000 sq.ft.

One fall application with 30–50% quick release/water soluble nitrogen. This will provide even release throughout fall.

Sept 1–20

Aerate 1

Broadleaf perennial weed control

Spot spray as needed. Fall is ideal time to control broadleaf weeds. Second best time is in spring shortly after flowering of dandelions.

Oct. 15–30

0.5 lbs. N/1000 sq.ft.

Optional—0.25 lbs N/1000 sq.ft.

Only needed on new lawns or areas that are thin or have suffered pest damage.

Oct. 15-Nov. 1

Continue mowing until grass stops growing.