Richmond
Spot-treat56°F↑ warming
Winter weeds are up. Spot-treat them on a mild day, or in early spring before they flower.
Winter weeds are up
Virginia Weed Watch · updated Nov 3, 1:18 AM CT
When to apply pre-emergent in Virginia
Live soil temperatures for Richmond, Virginia Beach, Arlington and Roanoke, updated every three hours. Weeds sprout by soil temperature, not by the calendar, so the right week moves from year to year.
Virginia 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 8 – Apr 15
Stops crabgrass and other summer weeds before they sprout.
Fall pre-emergentThis season
Typically by Aug 17 – 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 Virginia
Soil is 55–60°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.
Virginia Beach
Spot-treat60°F↑ warming
Winter weeds are up. Spot-treat them on a mild day, or in early spring before they flower.
Winter weeds are up
Arlington
Spot-treat56°F↑ warming
Winter weeds are up. Spot-treat them on a mild day, or in early spring before they flower.
Winter weeds are up
Roanoke
Spot-treat55°F↑ warming
Winter weeds are up. Spot-treat them on a mild day, or in early spring before they flower.
Winter weeds are up
Virginia 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) |
|---|---|---|
| Richmond | Mar 13 – Apr 1 | Apply by Aug 20 |
| Virginia Beach | Mar 8 – Mar 28 | Apply by Aug 27 |
| Arlington | Mar 23 – Apr 15 | Apply by Aug 21 |
| Roanoke | Mar 12 – Mar 30 | Apply by Aug 17 |
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 Virginia are identifying
We record the state each identification comes from. Virginia'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 Virginia this fall
Questions about Virginia
When should I apply crabgrass pre-emergent in Virginia?
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 13 – Apr 1 in Richmond; Mar 8 – Mar 28 in Virginia Beach; Mar 23 – Apr 15 in Arlington; Mar 12 – Mar 30 in Roanoke.
When should I apply fall pre-emergent in Virginia?
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 20 in Richmond; by Aug 27 in Virginia Beach; by Aug 21 in Arlington; by Aug 17 in Roanoke. Skip it if you are overseeding this fall, because it stops grass seed too.
What is the soil temperature in Virginia right now?
As of Nov 3, 1:18 AM CT: Richmond 56°F, Virginia Beach 60°F, Arlington 56°F, Roanoke 55°F (5-day average, about 2.4 inches down). Winter weeds are up — spot-treat across Virginia.
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.