Indianapolis
Treat broadleaf61°F↓ cooling
Fall is the best time to treat dandelions and clover: they pull weed killer down to their roots.
Broadleaf window Sep 15 – Nov 7
Indiana Weed Watch · updated Nov 3, 1:18 AM CT
When to apply pre-emergent in Indiana
Live soil temperatures for Indianapolis, Fort Wayne, South Bend and Evansville, updated every three hours. Weeds sprout by soil temperature, not by the calendar, so the right week moves from year to year.
In Indiana, pre-emergent is a spring job: it stops crabgrass. Fall is seeding season here, so fall weed control means treating broadleaf weeds instead.
Spring pre-emergentNext season
Typically Mar 14 – Apr 24
Stops crabgrass and other summer weeds before they sprout.
Fall: no pre-emergentThis season
Treat broadleaf weeds Sep 5 – Nov 7
Fall is seeding season here, and pre-emergent would stop grass seed too.
Right now · fall (seeding season)
Treat broadleaf weeds now across Indiana
Soil is 56–62°F now. In fall, dandelions, clover and creeping Charlie pull sugars — and weed killer — down to their roots. Seeding 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.
Fort Wayne
Treat broadleaf56°F↓ cooling
Fall is the best time to treat dandelions and clover: they pull weed killer down to their roots.
Broadleaf window Sep 5 – Oct 31
South Bend
Treat broadleaf56°F↓ cooling
Fall is the best time to treat dandelions and clover: they pull weed killer down to their roots.
Broadleaf window Sep 5 – Oct 31
Evansville
Treat broadleaf62°F↓ cooling
Fall is the best time to treat dandelions and clover: they pull weed killer down to their roots.
Broadleaf window Sep 7 – Nov 2
Indiana 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). In fall Indiana lawns are in seeding season, so there is no fall pre-emergent; the window shown is for treating broadleaf weeds instead, from September until two weeks after soil usually cools to 55°F.
| City | Spring pre-emergent (crabgrass) | Fall (seeding season) |
|---|---|---|
| Indianapolis | Mar 27 – Apr 13 | None (seeding season) · treat broadleaf Sep 15 – Nov 7 |
| Fort Wayne | Apr 12 – Apr 24 | None (seeding season) · treat broadleaf Sep 5 – Oct 31 |
| South Bend | Apr 11 – Apr 24 | None (seeding season) · treat broadleaf Sep 5 – Oct 31 |
| Evansville | Mar 14 – Mar 28 | None (seeding season) · treat broadleaf Sep 7 – Nov 2 |
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 Indiana are identifying
We record the state each identification comes from. Indiana'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 Indiana this fall
Questions about Indiana
When should I apply crabgrass pre-emergent in Indiana?
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 27 – Apr 13 in Indianapolis; Apr 12 – Apr 24 in Fort Wayne; Apr 11 – Apr 24 in South Bend; Mar 14 – Mar 28 in Evansville.
Should I put down pre-emergent in the fall in Indiana?
Usually not. Fall is the best time to seed a cool-season lawn in Indiana, and pre-emergent stops grass seed as well as weeds. Fall is the time to treat broadleaf weeds such as dandelion, clover and creeping Charlie, once the summer heat breaks and while they are still growing.
What is the soil temperature in Indiana right now?
As of Nov 3, 1:18 AM CT: Indianapolis 61°F, Fort Wayne 56°F, South Bend 56°F, Evansville 62°F (5-day average, about 2.4 inches down). Treat broadleaf weeds now across Indiana.
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.