Oklahoma Weed Watch · updated Nov 3, 1:18 AM CT

When to apply pre-emergent in Oklahoma

Live soil temperatures for Oklahoma City, Tulsa and Lawton, updated every three hours. Weeds sprout by soil temperature, not by the calendar, so the right week moves from year to year.

Oklahoma lawns get pre-emergent twice a year: in spring for crabgrass and other summer weeds, and in fall for winter weeds.

Spring pre-emergentNext season
Typically Mar 5 – Mar 19
Stops crabgrass and other summer weeds before they sprout.
Fall pre-emergentThis season
Typically by Sep 3 – Sep 22
Stops winter weeds (annual bluegrass, henbit, chickweed) before they sprout.
Skip it if you are overseeding this fall.
Right now · fall pre-emergent season
Winter weeds are germinating — apply now if you haven't across Oklahoma

Soil is 66°F now. They keep coming up in flushes into winter, so pre-emergent still helps. Overseeding this fall? Skip pre-emergent — it stops grass seed too.

Soil temperature by city

Soil 2 inches down, 5-day average: solid line = the last two weeks, dashed = the six-day forecast. Shaded = below 75°F, where winter weeds sprout — pre-emergent has to be down before the line gets there.

Oklahoma City

Apply ASAP
66°F↓ cooling

Soil has cooled to 75°F, so winter weeds are sprouting. Pre-emergent still stops later flushes.

75°Ftoday

Winter weeds are sprouting now

Tulsa

Apply ASAP
66°F↓ cooling

Soil has cooled to 75°F, so winter weeds are sprouting. Pre-emergent still stops later flushes.

75°Ftoday

Winter weeds are sprouting now

Lawton

Apply ASAP
66°F↓ cooling

Soil has cooled to 75°F, so winter weeds are sprouting. Pre-emergent still stops later flushes.

75°Ftoday

Winter weeds are sprouting now

Oklahoma pre-emergent calendar

Spring pre-emergent stops crabgrass. The window runs from the typical day soil warms to 50°F to the day it holds 55°F, when crabgrass starts germinating (2016–2025). Fall pre-emergent stops winter weeds: have it down a week before soil usually cools to 75°F, when they start germinating.

CitySpring pre-emergent (crabgrass)Fall pre-emergent (winter weeds)
Oklahoma CityMar 6 – Mar 18Apply by Sep 22
TulsaMar 11 – Mar 19Apply by Sep 3
LawtonMar 5 – Mar 18Apply by Sep 20

These are typical-year dates (the median of 2016–2025); any one year can run a couple of weeks earlier or later, which is what the live readings above are for. For your exact yard, check soil temperature by ZIP.

Recommended gear

Fall pre-emergents

Granular or liquid. Follow the label rate, and water it in.

Paid links. As an Amazon Associate, MeasureLawn earns from qualifying purchases.

Amazon

Scotts Halts Crabgrass & Grassy Weed Preventer

Beginner friendly

Pendimethalingranularcovers ~5,000 sq ft / 0.11 ac$24.97as of Nov 2, 10:00 AM UTC · may change
View at Amazon
Amazon

The Andersons Barricade Professional-Grade Granular

Beginner friendly

0.48% Prodiaminegranularcovers ~12,880 sq ft / 0.30 ac$79.88as of Nov 2, 10:00 AM UTC · may change
View at Amazon
Amazon

Dimension 2EW (Dithiopyr)

Liquid concentrate; 64 oz half gallon; mix with water and spray

Dithiopyrliquidcovers ~91,428 sq ft / 2.1 ac$158.00as of Nov 2, 10:00 AM UTC · may change
View at Amazon

What people in Oklahoma are identifying

We record the state each identification comes from. Oklahoma's list appears here once it has at least 40 identifications spread over 7 or more days — so no single scan stands out. Until then, see the national list, or add yours:

Identify a weed from a photo

Weeds to watch in Oklahoma this fall

Annual bluegrass (Poa annua)germinates as soil drops below 70°F · how to treat →Henbitwinter annual, purple spring flowers · how to treat →Chickweedwinter annual, mats in thin turf · how to treat →

Questions about Oklahoma

When should I apply crabgrass pre-emergent in Oklahoma?

Put crabgrass pre-emergent down as soil warms to 50°F, before it holds 55°F and crabgrass starts germinating. In a typical year (2016–2025) that window is Mar 6 – Mar 18 in Oklahoma City; Mar 11 – Mar 19 in Tulsa; Mar 5 – Mar 18 in Lawton.

When should I apply fall pre-emergent in Oklahoma?

Winter weeds such as annual bluegrass, henbit and chickweed start germinating as soil cools to about 75°F in late summer and fall, and most come up once it is below 70°F. Have fall pre-emergent down before they start: typically by Sep 22 in Oklahoma City; by Sep 3 in Tulsa; by Sep 20 in Lawton. Skip it if you are overseeding this fall, because it stops grass seed too.

What is the soil temperature in Oklahoma right now?

As of Nov 3, 1:18 AM CT: Oklahoma City 66°F, Tulsa 66°F, Lawton 66°F (5-day average, about 2.4 inches down). Winter weeds are germinating — apply now if you haven't across Oklahoma.

How the readings and dates are made, and their limits: Weed Watch method. Soil data: Open-Meteo.com (CC BY 4.0); typical dates: NASA POWER.