Frost Dates for Gaithersburg, MD 20877
Gaithersburg has 5 ZIP codes. The Gaithersburg, MD frost page lists all of them with their dates.
Last spring frost April 15 · First fall frost October 23 · 191 frost-free days · USDA Zone 7b
ZIP 20877 has about 38,500 people, one of 5 ZIP codes in Gaithersburg.
Long season: 191 frost-free days. Spring frost risk spans March 27–May 4 (38 days). Fall frost risk spans October 6–November 9 (34 days).
Frost probability for 20877
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | May 4 | April 15 | March 27 |
| Fall (first frost) | October 6 | October 23 | November 9 |
Dates come from NOAA 1971–2000 freeze probabilities at DALECARLIA RSVR (23.4 km away); the 50% date is the median year.
Which crops fit a 191-day season in Gaithersburg
In Gaithersburg (191 frost-free days, a long season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Mar 11 | Apr 29–May 6 | 149 | fits: 80 days to maturity, 149 available after Apr 29. | Jun 23 |
| Pepper | Mar 4 | Apr 29–May 6 | 149 | fits: 75 days to maturity, 149 available after Apr 29. | Jun 28 |
| Lettuce | Feb 18 | Mar 18–Mar 25 | 226 | two-plantings: Plant Mar 18 and again by Sep 1; both mature before Oct 30. | Sep 1 |
| Carrots | — | Mar 25–Apr 1 | 233 | fits: 70 days to maturity, 233 available after Mar 25. | Aug 21 |
| Cucumber | Mar 25 | Apr 29–May 6 | 163 | two-plantings: Plant Apr 29 and again by Jul 27; both mature before Oct 9. | Jul 27 |
| Beans | — | Apr 22–May 6 | 177 | two-plantings: Plant Apr 22 and again by Aug 3; both mature before Oct 16. | Aug 3 |
| Peas | — | Feb 18–Apr 29 | 254 | fits: 65 days to maturity, 254 available after Feb 18. | Aug 12 |
| Zucchini | Apr 1 | Apr 29–May 6 | 163 | two-plantings: Plant Apr 29 and again by Aug 1; both mature before Oct 9. | Aug 1 |
| Onion | Jan 21 | Mar 18–Apr 1 | 226 | fits: 100 days to maturity, 226 available after Mar 18. | — |
| Spinach | — | Feb 18–Apr 8 | 268 | two-plantings: Plant Feb 18 and again by Sep 20; both mature before Nov 13. | Sep 20 |
| Kale | Feb 4 | Mar 18–Apr 1 | 240 | two-plantings: Plant Mar 18 and again by Sep 5; both mature before Nov 13. | Sep 5 |
| Broccoli | Feb 18 | Mar 18–Apr 1 | 226 | fits: 80 days to maturity, 226 available after Mar 18. | Jul 28 |
| Cabbage | Feb 18 | Mar 18–Apr 1 | 240 | fits: 70 days to maturity, 240 available after Mar 18. | Aug 21 |
| Radish | — | Feb 18–May 13 | 254 | two-plantings: Plant Feb 18 and again by Sep 21; both mature before Oct 30. | Sep 21 |
| Beets | — | Feb 18–May 13 | 254 | two-plantings: Plant Feb 18 and again by Aug 22; both mature before Oct 30. | Aug 22 |
| Potatoes | — | Apr 1–Apr 8 | 212 | fits: 90 days to maturity, 212 available after Apr 1. | — |
| Garlic | — | Oct 23 | 296 | overwinter: Plant Oct 23 to Nov 13; harvest the following summer. | Nov 13 |
| Strawberry | — | Mar 11–May 6 | 247 | perennial: A perennial: plant Mar 11; it fruits from the following year and keeps producing for several years. | — |
| Corn | Mar 18 | Apr 22–Apr 29 | 163 | fits: 75 days to maturity, 163 available after Apr 22. | Jul 5 |
| Pumpkin | Apr 1 | Apr 29–Apr 29 | 156 | fits: 100 days to maturity, 156 available after Apr 29. | Jun 10 |
| Cauliflower | Mar 4 | Apr 8–Apr 22 | 205 | fits: 75 days to maturity, 205 available after Apr 8. | Aug 2 |
| Swiss Chard | Feb 18 | Apr 1–Apr 1 | 212 | two-plantings: Plant Apr 1 and again by Aug 22; both mature before Oct 30. | Aug 22 |
| Arugula | — | Feb 18–May 13 | 268 | two-plantings: Plant Feb 18 and again by Sep 20; both mature before Nov 13. | Sep 20 |
| Brussel Sprouts | Feb 18 | Mar 18–Apr 1 | 240 | fits: 100 days to maturity, 240 available after Mar 18. | Jul 22 |
| Butternut Squash | Apr 1 | Apr 29–May 6 | 156 | fits: 100 days to maturity, 156 available after Apr 29. | Jun 10 |
| Eggplant | Feb 25 | Apr 29–May 6 | 149 | fits: 70 days to maturity, 149 available after Apr 29. | Jul 3 |
| Okra | Mar 18 | Apr 22–Apr 29 | 170 | two-plantings: Plant Apr 22 and again by Aug 1; both mature before Oct 9. | Aug 1 |
| Basil | Mar 11 | May 6–May 6 | 156 | two-plantings: Plant May 6 and again by Jul 27; both mature before Oct 9. | Jul 27 |
| Cilantro | — | Mar 18–Apr 8 | 226 | two-plantings: Plant Mar 18 and again by Aug 27; both mature before Oct 30. | Aug 27 |
| Parsley | Feb 4 | Apr 22–Apr 29 | 191 | fits: 70 days to maturity, 191 available after Apr 22. | Aug 7 |
| Celery | Feb 4 | Apr 22–May 6 | 191 | fits: 120 days to maturity, 191 available after Apr 22. | Jun 18 |
| Scallions | Feb 4 | Mar 18–Apr 1 | 240 | two-plantings: Plant Mar 18 and again by Aug 31; both mature before Nov 13. | Aug 31 |
| Turnip | — | Mar 18–Apr 1 | 240 | two-plantings: Plant Mar 18 and again by Sep 10; both mature before Nov 13. | Sep 10 |
| Kohlrabi | — | Mar 4–Mar 18 | 254 | two-plantings: Plant Mar 4 and again by Sep 5; both mature before Nov 13. | Sep 5 |
| Bok Choy | Mar 18 | Apr 8–Apr 15 | 205 | two-plantings: Plant Apr 8 and again by Sep 1; both mature before Oct 30. | Sep 1 |
| Collards | Feb 4 | Mar 18–Apr 1 | 240 | two-plantings: Plant Mar 18 and again by Aug 31; both mature before Nov 13. | Aug 31 |
| Cantaloupe | Apr 1 | Apr 29–May 6 | 149 | fits: 85 days to maturity, 149 available after Apr 29. | Jun 18 |
| Chives | Jan 21 | Apr 22–Apr 29 | 205 | fits: 90 days to maturity, 205 available after Apr 22. | — |
| Dill | — | Feb 18–May 13 | 254 | two-plantings: Plant Feb 18 and again by Aug 22; both mature before Oct 30. | Aug 22 |
| Oregano | Feb 4 | Apr 22–Apr 29 | 205 | fits: 80 days to maturity, 205 available after Apr 22. | — |
| Rosemary | Jan 21 | Apr 22–Apr 29 | 191 | fits: 80 days to maturity, 191 available after Apr 22. | — |
| Sage | Feb 18 | Apr 22–Apr 29 | 205 | fits: 75 days to maturity, 205 available after Apr 22. | — |
| Thyme | Feb 4 | Apr 22–Apr 29 | 205 | fits: 90 days to maturity, 205 available after Apr 22. | — |
| Calendula | Mar 4 | Apr 1–Apr 15 | 212 | two-plantings: Plant Apr 1 and again by Aug 27; both mature before Oct 30. | Aug 27 |
| Cosmos | Mar 18 | Apr 15–Apr 29 | 177 | two-plantings: Plant Apr 15 and again by Jul 27; both mature before Oct 9. | Jul 27 |
| Lavender | Jan 21 | Apr 15–Apr 29 | 212 | fits: 90 days to maturity, 212 available after Apr 15. | — |
| Marigolds | Mar 4 | Apr 15–Apr 22 | 177 | two-plantings: Plant Apr 15 and again by Aug 6; both mature before Oct 9. | Aug 6 |
| Melons | Apr 1 | Apr 29–May 6 | 149 | fits: 85 days to maturity, 149 available after Apr 29. | Jun 18 |
| Mint | — | Apr 15–Apr 29 | 212 | fits: 90 days to maturity, 212 available after Apr 15. | — |
| Nasturtiums | Mar 18 | Apr 15–Apr 22 | 177 | two-plantings: Plant Apr 15 and again by Aug 1; both mature before Oct 9. | Aug 1 |
| Pole Beans | — | Apr 22–May 6 | 170 | fits: 65 days to maturity, 170 available after Apr 22. | Jul 22 |
| Spaghetti Squash | Apr 1 | Apr 29–May 6 | 156 | fits: 90 days to maturity, 156 available after Apr 29. | Jun 20 |
| Sunflowers | — | Apr 15–Apr 29 | 177 | fits: 70 days to maturity, 177 available after Apr 15. | Jul 17 |
| Tomatillos | Feb 18 | Apr 22–Apr 29 | 156 | fits: 75 days to maturity, 156 available after Apr 22. | Jun 28 |
| Watermelon | Apr 1 | Apr 22–Apr 29 | 156 | fits: 80 days to maturity, 156 available after Apr 22. | Jun 23 |
| Yellow Squash | Apr 1 | Apr 29–May 6 | 163 | two-plantings: Plant Apr 29 and again by Aug 1; both mature before Oct 9. | Aug 1 |
| Zinnias | Mar 18 | Apr 15–Apr 29 | 177 | two-plantings: Plant Apr 15 and again by Jul 27; both mature before Oct 9. | Jul 27 |
Month by month in Gaithersburg
| Month | What to do |
|---|---|
| January | Start indoors: Chives (Jan 21), Lavender (Jan 21), Onion (Jan 21), Rosemary (Jan 21). |
| February | Start indoors: Celery (Feb 4), Collards (Feb 4), Kale (Feb 4), Oregano (Feb 4), Parsley (Feb 4), Scallions (Feb 4), +9 more. Direct sow from: Arugula (Feb 18), Beets (Feb 18), Dill (Feb 18), Peas (Feb 18), Radish (Feb 18), Spinach (Feb 18). |
| March | Start indoors: Calendula (Mar 4), Cauliflower (Mar 4), Marigolds (Mar 4), Pepper (Mar 4), Basil (Mar 11), Tomato (Mar 11), +7 more. Direct sow from: Kohlrabi (Mar 4), Cilantro (Mar 18), Turnip (Mar 18), Carrots (Mar 25). Transplant from: Broccoli (Mar 18), Brussel Sprouts (Mar 18), Cabbage (Mar 18), Collards (Mar 18), Kale (Mar 18), Lettuce (Mar 18), +2 more. Plant: Strawberry (Mar 11). |
| April | Start indoors: Butternut Squash (Apr 1), Cantaloupe (Apr 1), Melons (Apr 1), Pumpkin (Apr 1), Spaghetti Squash (Apr 1), Watermelon (Apr 1), +2 more. Direct sow from: Potatoes (Apr 1), Sunflowers (Apr 15), Beans (Apr 22), Pole Beans (Apr 22). Transplant from: Calendula (Apr 1), Swiss Chard (Apr 1), Bok Choy (Apr 8), Cauliflower (Apr 8), Cosmos (Apr 15), Lavender (Apr 15), +26 more. Last frost around April 15. |
| May | Transplant from: Basil (May 6). |
| June | Last sowing dates: Butternut Squash (Jun 10), Pumpkin (Jun 10), Cantaloupe (Jun 18), Celery (Jun 18), Melons (Jun 18), Spaghetti Squash (Jun 20), +4 more. |
| July | Last sowing dates: Eggplant (Jul 3), Corn (Jul 5), Sunflowers (Jul 17), Brussel Sprouts (Jul 22), Pole Beans (Jul 22), Basil (Jul 27), +4 more. |
| August | Last sowing dates: Nasturtiums (Aug 1), Okra (Aug 1), Yellow Squash (Aug 1), Zucchini (Aug 1), Cauliflower (Aug 2), Beans (Aug 3), +12 more. |
| September | Last sowing dates: Bok Choy (Sep 1), Lettuce (Sep 1), Kale (Sep 5), Kohlrabi (Sep 5), Turnip (Sep 10), Arugula (Sep 20), +2 more. |
| October | Direct sow from: Garlic (Oct 23). First frost around October 23. |
| November | Last sowing dates: Garlic (Nov 13). |
| December | Clean up spent plants. Add compost to beds. Rest, review, and plan next year's garden. |
Frequently Asked Questions
What is the last frost date for Gaithersburg, MD (ZIP 20877)?
The median last spring frost date for Gaithersburg, MD (ZIP code 20877) is around April 15. This is the 50th-percentile date — meaning half of all years see frost end before this date. Use the 10% and 90% dates to understand the full range of risk in your area. One year in ten frost ends before March 27; one in ten it runs past May 4.
What is the first fall frost date in Gaithersburg, MD?
The median first fall frost date for Gaithersburg, MD is around October 23. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses. The first frost arrives around October 6 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Gaithersburg, MD?
The frost-free growing season in Gaithersburg is about 191 days. This window — from your last spring frost to your first fall frost — is when warm-season vegetables thrive. Cold-hardy crops like kale, spinach, and peas can extend your season by weeks on either side. In Gaithersburg (191 frost-free days, a long season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.
What USDA hardiness zone is Gaithersburg, MD?
Gaithersburg, MD is in USDA hardiness zone 7b (2023 USDA Plant Hardiness Zone Map). Zones come from the average coldest winter temperature, so they tell you which perennials survive the winter; the frost dates on this page tell you when to plant.
When should I start tomatoes indoors in Gaithersburg, MD?
Start tomatoes indoors Mar 11 and plant out Apr 29 in Gaithersburg. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Gaithersburg?
Two: plant Mar 18 and again by Sep 1; both mature before Oct 30.
When do I plant garlic in Gaithersburg?
Oct 23 to Nov 13; it overwinters and is ready the following summer.
Can I get two tomato crops in Gaithersburg?
Yes: plant out Apr 29 for a summer crop, and set out a second round of transplants by Jun 23 for a fall crop.
Nearby and related
- Frost dates for Montgomery Village, MD 20886 (2.7 mi)
- Frost dates for Derwood, MD 20855 (3 mi)
- Frost dates for Rockville, MD 20850 (3.5 mi)
- Frost dates for Gaithersburg, MD 20878 (3.7 mi)
- Frost dates for Germantown, MD 20874 (5.9 mi)
- When to plant in Gaithersburg, MD: month-by-month guide
- When to plant in MD
- When to plant Peppers in MD
- When to plant Cucumbers in MD
- When to plant Zucchini in MD
- When to plant Butternut Squash in MD
- When to plant Basil in MD
- When to plant Sweet Corn in MD
- Look up another ZIP