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

When to apply pre-emergent in Rhode Island

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

In Rhode Island, 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 Apr 15 – May 7
Stops crabgrass and other summer weeds before they sprout.
Fall: no pre-emergentThis season
Treat broadleaf weeds Sep 4 – Nov 2
Fall is seeding season here, and pre-emergent would stop grass seed too.
Right now · fall (seeding season)
Treat broadleaf weeds now across Rhode Island

Soil is 52–54°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.

Providence

Treat broadleaf
52°F↑ warming

Fall is the best time to treat dandelions and clover: they pull weed killer down to their roots.

today

Broadleaf window Sep 4 – Oct 31

Newport

Treat broadleaf
54°F↑ warming

Fall is the best time to treat dandelions and clover: they pull weed killer down to their roots.

today

Broadleaf window Sep 5 – Nov 2

Rhode Island 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 Rhode Island 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.

CitySpring pre-emergent (crabgrass)Fall (seeding season)
ProvidenceApr 15 – May 3None (seeding season) · treat broadleaf Sep 4 – Oct 31
NewportApr 19 – May 7None (seeding season) · treat broadleaf Sep 5 – 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 Rhode Island are identifying

We record the state each identification comes from. Rhode Island'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 Rhode Island this fall

Dandelionfall is the best time to treat · how to treat →White clovertreat while still growing · how to treat →Creeping Charlieneeds triclopyr; fall works best · how to treat →

Questions about Rhode Island

When should I apply crabgrass pre-emergent in Rhode Island?

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 Apr 15 – May 3 in Providence; Apr 19 – May 7 in Newport.

Should I put down pre-emergent in the fall in Rhode Island?

Usually not. Fall is the best time to seed a cool-season lawn in Rhode Island, 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 Rhode Island right now?

As of Nov 3, 1:18 AM CT: Providence 52°F, Newport 54°F (5-day average, about 2.4 inches down). Treat broadleaf weeds now across Rhode Island.

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.