Frost dates for Gaithersburg, MD
When the last spring frost and first fall frost usually come, and when to plant, from 30 years of NOAA weather records.
Last spring frost
April 1
typical year
Safe to plant
April 15
frost is over in 9 of 10 years
First fall frost
November 6
typical year
Growing season
219 days
frost-free, typical year
Frost watch this week
Tonight's and the next six nights' lows from the National Weather Service forecast for the station's location. Frost: 32°F or colder. Possible frost: 33–36°F, mostly in low spots on clear, still nights.
When to plant
Counted from this page's frost dates. Warm-season crops wait for the safe-to-plant date.
| Crop | Start indoors | Plant outside | Fall planting |
|---|---|---|---|
| Cool-season crops | |||
| Peas | – | Mar 4 – 18 | – |
| Spinach | – | Feb 18 – Mar 11 | Sep 11 – 25 |
| Lettuce | – | Mar 4 – 25 | Sep 11 – 25 |
| Radishes | – | Mar 4 – Apr 15 | Sep 25 – Oct 9 |
| Onions | – | Mar 4 – 18 | – |
| Potatoes | – | Mar 11 – 25 | – |
| Carrots | – | Mar 11 – Apr 1 | Aug 14 – 28 |
| Beets | – | Mar 4 – 18 | Aug 28 – Sep 11 |
| Kale | Jan 21 – Feb 4 | Mar 4 – 18 | Aug 28 – Sep 11 |
| Broccoli | Jan 21 – Feb 4 | Mar 18 – Apr 1 | Aug 28 – Sep 11 |
| Cabbage | Jan 7 – 21 | Mar 4 – 18 | Aug 28 – Sep 11 |
| Garlic | – | – | Sep 25 – Oct 16 |
| Warm-season crops | |||
| Tomatoes | Feb 18 – Mar 4 | Apr 15 – 29 | – |
| Peppers | Feb 11 – 25 | Apr 22 – May 6 | – |
| Cucumbers | – | Apr 15 – May 6 | – |
| Zucchini | – | Apr 15 – May 13 | – |
| Pumpkins | – | Apr 15 – May 6 | – |
| Green beans | – | Apr 15 – Aug 28 | – |
| Sweet corn | – | Apr 15 – May 13 | – |
| Basil | Mar 11 – 25 | Apr 22 – 29 | – |
Onions: from sets. Green beans: until 10 weeks before the first fall frost. Garlic: harvest next summer.
The year at a glance
Start indoors Plant outside Fall planting
The chance of frost, by date
| 1 year in 10 | Half of years | 9 years in 10 | |
|---|---|---|---|
| Spring frost after | April 15 | April 1 | March 19 |
| Fall frost before | October 24 | November 6 | November 21 |
Frost here means 32°F or colder. Read across: in 1 year in 10, spring frost carries on past the first date, which is why that date is the safe-to-plant date.
Hard freeze (28°F)
A hard freeze kills most garden plants, even hardy ones. The last one in spring usually comes around March 22 (April 4 in a late year), and the first one in fall around November 19.
Towns that use these dates
This is the nearest NOAA station with frost records for 5 towns.
Gaithersburg, Rockville, Garrett Park, Washington Grove, Brookeville
Where these dates come from
NOAA weather station ROCKVILLE 1 NE, MD US (USC00187705), 1991–2020 climate normals. It's the nearest station for 19 zip codes, all within 9 miles:
20832, 20833, 20850, 20851, 20852, 20853, 20854, 20855, 20860, 20862, 20874, 20877, 20878, 20879, 20880, 20895, 20896, 20899, 20906
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.