Louisville
Spot-treat61°F↓ cooling
Winter weeds are up. Spot-treat them on a mild day, or in early spring before they flower.
Winter weeds are up
Kentucky Weed Watch · updated Nov 3, 1:18 AM CT
When to apply pre-emergent in Kentucky
Live soil temperatures for Louisville, Lexington and Bowling Green, updated every three hours. Weeds sprout by soil temperature, not by the calendar, so the right week moves from year to year.
Kentucky 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 12 – Apr 9
Stops crabgrass and other summer weeds before they sprout.
Fall pre-emergentThis season
Typically by Aug 24 – Aug 27
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 up — spot-treat across Kentucky
Soil is 60–61°F now. Spot-treat them with a post-emergent on a mild day, or in early spring before they flower.
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.
Lexington
Spot-treat60°F↓ cooling
Winter weeds are up. Spot-treat them on a mild day, or in early spring before they flower.
Winter weeds are up
Bowling Green
Spot-treat60°F↓ cooling
Winter weeds are up. Spot-treat them on a mild day, or in early spring before they flower.
Winter weeds are up
Kentucky 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.
| City | Spring pre-emergent (crabgrass) | Fall pre-emergent (winter weeds) |
|---|---|---|
| Louisville | Mar 15 – Apr 2 | Apply by Aug 27 |
| Lexington | Mar 16 – Apr 9 | Apply by Aug 27 |
| Bowling Green | Mar 12 – Mar 28 | Apply by Aug 24 |
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.
What people in Kentucky are identifying
We record the state each identification comes from. Kentucky'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 photoWeeds to watch in Kentucky this fall
Questions about Kentucky
When should I apply crabgrass pre-emergent in Kentucky?
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 15 – Apr 2 in Louisville; Mar 16 – Apr 9 in Lexington; Mar 12 – Mar 28 in Bowling Green.
When should I apply fall pre-emergent in Kentucky?
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 Aug 27 in Louisville; by Aug 27 in Lexington; by Aug 24 in Bowling Green. Skip it if you are overseeding this fall, because it stops grass seed too.
What is the soil temperature in Kentucky right now?
As of Nov 3, 1:18 AM CT: Louisville 61°F, Lexington 60°F, Bowling Green 60°F (5-day average, about 2.4 inches down). Winter weeds are up — spot-treat across Kentucky.
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.