LawnWeather

Rockville, MD Lawn Care Calendar

In a typical year, put down crabgrass preventer in Rockville between Mar 27 and Apr 21. The best time to overseed is between Aug 24 and Oct 13. The last spring frost usually comes around Apr 11. Most lawns here are cool-season grass (tall fescue, Kentucky bluegrass, ryegrass).

Typical lawn care dates in Rockville

Crabgrass preventer (pre-emergent)
Mar 27 – Apr 21
Spring fertilizer
Apr 14 – May 19
Overseeding & seeding
Aug 24 – Oct 13
Fall fertilizer
Sep 16 – Nov 19
Light band: typical frost-free season. Bars: typical windows.
TaskTypical window
Crabgrass preventer (pre-emergent)Crabgrass sprouts once soil stays above 55°F. Apply when soil reaches 50°F, before that happens.Mar 27 – Apr 21
Spring fertilizerA light feeding once soil warms past 55°F and the grass is actively growing.Apr 14 – May 19
Overseeding & seedingLate summer to early fall: seedlings need about 6–10 weeks of growth before the first frost.Aug 24 – Oct 13
Fall fertilizerThe most important feeding for cool-season grass, from early fall until soil cools to about 45°F.Sep 16 – Nov 19

Median dates, 2016–2025, from NOAA weather data for Rockville. This year's dates can differ by a few weeks.

Month-by-month lawn care in Rockville

  1. JanuaryNo treatments due; mow as needed.
  2. FebruaryNo treatments due; mow as needed.
  3. MarchCrabgrass preventer (pre-emergent)
  4. AprilCrabgrass preventer (pre-emergent)Spring fertilizer
  5. MaySpring fertilizer
  6. JuneNo treatments due; mow as needed.
  7. JulyNo treatments due; mow as needed.
  8. AugustOverseeding & seeding
  9. SeptemberOverseeding & seedingFall fertilizer
  10. OctoberOverseeding & seedingFall fertilizer
  11. NovemberFall fertilizer
  12. DecemberNo treatments due; mow as needed.

Soil temperature in Rockville by month

Average soil temperature 4 inches down, estimated from 2016–2025 weather. It bottoms out in January at 35°F and peaks in July at 78°F. Crabgrass preventer goes down when it reaches 50°F, usually around Mar 27.

JanFebMarAprMayJunJulAugSepOctNovDec
35°F38°F45°F55°F63°F72°F78°F76°F70°F59°F47°F38°F

Rockville lawn timing, year by year

Over the last 10 years, soil in Rockville reached 50°F, the signal for crabgrass preventer, as early as Mar 10 (2016) and as late as Apr 13 (2018): 34 days apart. A fixed calendar date can't follow that, which is why the report above uses this year's soil temperature. Between the typical last spring frost (Apr 11) and first fall frost (Nov 7), the growing season lasts about 210 days.

YearCrabgrass window openedLast spring frostFirst fall frost
2025Mar 17Apr 10Nov 11
2024Mar 14Mar 26Nov 13
2023Apr 4Apr 9Nov 2
2022Mar 19Apr 11Nov 14
2021Mar 25Apr 22Nov 3
2020Mar 28May 10Nov 18
2019Apr 7Apr 3Nov 2
2018Apr 13Apr 18Oct 22
2017Apr 3Mar 24Nov 11
2016Mar 10Apr 11Oct 26

Estimated from daily temperatures for Rockville. A dash means it didn't happen that year.

Frequently asked questions

When should I apply pre-emergent in Rockville?

In a typical year, between Mar 27 and Apr 21. Put it down when soil reaches 50°F, before it stays above 55°F and crabgrass starts sprouting. Early springs move this up by a week or more, so check this year's soil temperature above.

When is the best time to plant grass seed in Rockville?

Early fall, typically Aug 24 – Oct 13, while soil cools from 65°F toward 50°F.

When is the last frost in Rockville?

The median last spring frost is Apr 11 and the median first fall frost is Nov 7 (2016–2025).

How long is the growing season in Rockville?

About 210 days, from the median last spring frost on Apr 11 to the median first fall frost on Nov 7 (2016–2025).

Lawn care guides

Growing vegetables too? See the Rockville planting calendarfor when to start seeds and plant outside.

More Maryland lawn calendars

Nearby cities in other states