Frost Dates for Westminster, MD 21157
Last spring frost April 30 · First fall frost October 13 · 166 frost-free days · USDA Zone 7a
ZIP 21157 has about 39,000 people, the largest of 2 ZIP codes in Westminster.
Moderate season: 166 frost-free days. Spring frost risk spans April 13–May 15 (32 days). Fall frost risk spans September 29–October 26 (27 days).
Frost probability for 21157
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | May 15 | April 30 | April 13 |
| Fall (first frost) | September 29 | October 13 | October 26 |
Dates come from NOAA 1971–2000 freeze probabilities at CLARKSVILLE 3 NNE (33.0 km away); the 50% date is the median year.
Frost dates by ZIP code in Westminster, MD
| ZIP | Last spring frost (50%) | First fall frost (50%) | Zone |
|---|---|---|---|
| 21157 | April 30 | October 13 | 7a |
| 21158 | April 30 | October 13 | 7a |
Which crops fit a 166-day season in Westminster
In Westminster (166 frost-free days, a moderate season), 31 of 56 planner crops fit outright, 24 get two plantings, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Mar 26 | May 14–May 21 | 124 | fits: 80 days to maturity, 124 available after May 14. | Jun 13 |
| Pepper | Mar 19 | May 14–May 21 | 124 | fits: 75 days to maturity, 124 available after May 14. | Jun 18 |
| Lettuce | Mar 5 | Apr 2–Apr 9 | 201 | two-plantings: Plant Apr 2 and again by Aug 22; both mature before Oct 20. | Aug 22 |
| Carrots | — | Apr 9–Apr 16 | 208 | fits: 70 days to maturity, 208 available after Apr 9. | Aug 11 |
| Cucumber | Apr 9 | May 14–May 21 | 138 | two-plantings: Plant May 14 and again by Jul 17; both mature before Sep 29. | Jul 17 |
| Beans | — | May 7–May 21 | 152 | two-plantings: Plant May 7 and again by Jul 24; both mature before Oct 6. | Jul 24 |
| Peas | — | Mar 5–May 14 | 229 | fits: 65 days to maturity, 229 available after Mar 5. | Aug 2 |
| Zucchini | Apr 16 | May 14–May 21 | 138 | two-plantings: Plant May 14 and again by Jul 22; both mature before Sep 29. | Jul 22 |
| Onion | Feb 5 | Apr 2–Apr 16 | 201 | fits: 100 days to maturity, 201 available after Apr 2. | — |
| Spinach | — | Mar 5–Apr 23 | 243 | two-plantings: Plant Mar 5 and again by Sep 10; both mature before Nov 3. | Sep 10 |
| Kale | Feb 19 | Apr 2–Apr 16 | 215 | two-plantings: Plant Apr 2 and again by Aug 26; both mature before Nov 3. | Aug 26 |
| Broccoli | Mar 5 | Apr 2–Apr 16 | 201 | fits: 80 days to maturity, 201 available after Apr 2. | Jul 18 |
| Cabbage | Mar 5 | Apr 2–Apr 16 | 215 | fits: 70 days to maturity, 215 available after Apr 2. | Aug 11 |
| Radish | — | Mar 5–May 28 | 229 | two-plantings: Plant Mar 5 and again by Sep 11; both mature before Oct 20. | Sep 11 |
| Beets | — | Mar 5–May 28 | 229 | two-plantings: Plant Mar 5 and again by Aug 12; both mature before Oct 20. | Aug 12 |
| Potatoes | — | Apr 16–Apr 23 | 187 | fits: 90 days to maturity, 187 available after Apr 16. | — |
| Garlic | — | Oct 13 | 271 | overwinter: Plant Oct 13 to Nov 3; harvest the following summer. | Nov 3 |
| Strawberry | — | Mar 26–May 21 | 222 | perennial: A perennial: plant Mar 26; it fruits from the following year and keeps producing for several years. | — |
| Corn | Apr 2 | May 7–May 14 | 138 | fits: 75 days to maturity, 138 available after May 7. | Jun 25 |
| Pumpkin | Apr 16 | May 14–May 14 | 131 | fits: 100 days to maturity, 131 available after May 14. | May 31 |
| Cauliflower | Mar 19 | Apr 23–May 7 | 180 | fits: 75 days to maturity, 180 available after Apr 23. | Jul 23 |
| Swiss Chard | Mar 5 | Apr 16–Apr 16 | 187 | two-plantings: Plant Apr 16 and again by Aug 12; both mature before Oct 20. | Aug 12 |
| Arugula | — | Mar 5–May 28 | 243 | two-plantings: Plant Mar 5 and again by Sep 10; both mature before Nov 3. | Sep 10 |
| Brussel Sprouts | Mar 5 | Apr 2–Apr 16 | 215 | fits: 100 days to maturity, 215 available after Apr 2. | Jul 12 |
| Butternut Squash | Apr 16 | May 14–May 21 | 131 | fits: 100 days to maturity, 131 available after May 14. | May 31 |
| Eggplant | Mar 12 | May 14–May 21 | 124 | fits: 70 days to maturity, 124 available after May 14. | Jun 23 |
| Okra | Apr 2 | May 7–May 14 | 145 | two-plantings: Plant May 7 and again by Jul 22; both mature before Sep 29. | Jul 22 |
| Basil | Mar 26 | May 21–May 21 | 131 | fits: 60 days to maturity, 131 available after May 21. | Jul 17 |
| Cilantro | — | Apr 2–Apr 23 | 201 | two-plantings: Plant Apr 2 and again by Aug 17; both mature before Oct 20. | Aug 17 |
| Parsley | Feb 19 | May 7–May 14 | 166 | fits: 70 days to maturity, 166 available after May 7. | Jul 28 |
| Celery | Feb 19 | May 7–May 21 | 166 | fits: 120 days to maturity, 166 available after May 7. | Jun 8 |
| Scallions | Feb 19 | Apr 2–Apr 16 | 215 | two-plantings: Plant Apr 2 and again by Aug 21; both mature before Nov 3. | Aug 21 |
| Turnip | — | Apr 2–Apr 16 | 215 | two-plantings: Plant Apr 2 and again by Aug 31; both mature before Nov 3. | Aug 31 |
| Kohlrabi | — | Mar 19–Apr 2 | 229 | two-plantings: Plant Mar 19 and again by Aug 26; both mature before Nov 3. | Aug 26 |
| Bok Choy | Apr 2 | Apr 23–Apr 30 | 180 | two-plantings: Plant Apr 23 and again by Aug 22; both mature before Oct 20. | Aug 22 |
| Collards | Feb 19 | Apr 2–Apr 16 | 215 | two-plantings: Plant Apr 2 and again by Aug 21; both mature before Nov 3. | Aug 21 |
| Cantaloupe | Apr 16 | May 14–May 21 | 124 | fits: 85 days to maturity, 124 available after May 14. | Jun 8 |
| Chives | Feb 5 | May 7–May 14 | 180 | fits: 90 days to maturity, 180 available after May 7. | — |
| Dill | — | Mar 5–May 28 | 229 | two-plantings: Plant Mar 5 and again by Aug 12; both mature before Oct 20. | Aug 12 |
| Oregano | Feb 19 | May 7–May 14 | 180 | fits: 80 days to maturity, 180 available after May 7. | — |
| Rosemary | Feb 5 | May 7–May 14 | 166 | fits: 80 days to maturity, 166 available after May 7. | — |
| Sage | Mar 5 | May 7–May 14 | 180 | fits: 75 days to maturity, 180 available after May 7. | — |
| Thyme | Feb 19 | May 7–May 14 | 180 | fits: 90 days to maturity, 180 available after May 7. | — |
| Calendula | Mar 19 | Apr 16–Apr 30 | 187 | two-plantings: Plant Apr 16 and again by Aug 17; both mature before Oct 20. | Aug 17 |
| Cosmos | Apr 2 | Apr 30–May 14 | 152 | two-plantings: Plant Apr 30 and again by Jul 17; both mature before Sep 29. | Jul 17 |
| Lavender | Feb 5 | Apr 30–May 14 | 187 | fits: 90 days to maturity, 187 available after Apr 30. | — |
| Marigolds | Mar 19 | Apr 30–May 7 | 152 | two-plantings: Plant Apr 30 and again by Jul 27; both mature before Sep 29. | Jul 27 |
| Melons | Apr 16 | May 14–May 21 | 124 | fits: 85 days to maturity, 124 available after May 14. | Jun 8 |
| Mint | — | Apr 30–May 14 | 187 | fits: 90 days to maturity, 187 available after Apr 30. | — |
| Nasturtiums | Apr 2 | Apr 30–May 7 | 152 | two-plantings: Plant Apr 30 and again by Jul 22; both mature before Sep 29. | Jul 22 |
| Pole Beans | — | May 7–May 21 | 145 | fits: 65 days to maturity, 145 available after May 7. | Jul 12 |
| Spaghetti Squash | Apr 16 | May 14–May 21 | 131 | fits: 90 days to maturity, 131 available after May 14. | Jun 10 |
| Sunflowers | — | Apr 30–May 14 | 152 | fits: 70 days to maturity, 152 available after Apr 30. | Jul 7 |
| Tomatillos | Mar 5 | May 7–May 14 | 131 | fits: 75 days to maturity, 131 available after May 7. | Jun 18 |
| Watermelon | Apr 16 | May 7–May 14 | 131 | fits: 80 days to maturity, 131 available after May 7. | Jun 13 |
| Yellow Squash | Apr 16 | May 14–May 21 | 138 | two-plantings: Plant May 14 and again by Jul 22; both mature before Sep 29. | Jul 22 |
| Zinnias | Apr 2 | Apr 30–May 14 | 152 | two-plantings: Plant Apr 30 and again by Jul 17; both mature before Sep 29. | Jul 17 |
Month by month in Westminster
| Month | What to do |
|---|---|
| January | Plan your garden layout and order seeds. Research varieties suited to your frost dates. |
| February | Start indoors: Chives (Feb 5), Lavender (Feb 5), Onion (Feb 5), Rosemary (Feb 5), Celery (Feb 19), Collards (Feb 19), +5 more. |
| March | Start indoors: Broccoli (Mar 5), Brussel Sprouts (Mar 5), Cabbage (Mar 5), Lettuce (Mar 5), Sage (Mar 5), Swiss Chard (Mar 5), +8 more. Direct sow from: Arugula (Mar 5), Beets (Mar 5), Dill (Mar 5), Peas (Mar 5), Radish (Mar 5), Spinach (Mar 5), +1 more. Plant: Strawberry (Mar 26). |
| April | Start indoors: Bok Choy (Apr 2), Corn (Apr 2), Cosmos (Apr 2), Nasturtiums (Apr 2), Okra (Apr 2), Zinnias (Apr 2), +9 more. Direct sow from: Cilantro (Apr 2), Turnip (Apr 2), Carrots (Apr 9), Potatoes (Apr 16), Sunflowers (Apr 30). Transplant from: Broccoli (Apr 2), Brussel Sprouts (Apr 2), Cabbage (Apr 2), Collards (Apr 2), Kale (Apr 2), Lettuce (Apr 2), +12 more. Last frost around April 30. |
| May | Direct sow from: Beans (May 7), Pole Beans (May 7). Transplant from: Celery (May 7), Chives (May 7), Corn (May 7), Okra (May 7), Oregano (May 7), Parsley (May 7), +17 more. Last sowing dates: Butternut Squash (May 31), Pumpkin (May 31). |
| June | Last sowing dates: Cantaloupe (Jun 8), Celery (Jun 8), Melons (Jun 8), Spaghetti Squash (Jun 10), Tomato (Jun 13), Watermelon (Jun 13), +4 more. |
| July | Last sowing dates: Sunflowers (Jul 7), Brussel Sprouts (Jul 12), Pole Beans (Jul 12), Basil (Jul 17), Cosmos (Jul 17), Cucumber (Jul 17), +10 more. |
| August | Last sowing dates: Peas (Aug 2), Cabbage (Aug 11), Carrots (Aug 11), Beets (Aug 12), Dill (Aug 12), Swiss Chard (Aug 12), +9 more. |
| September | Last sowing dates: Arugula (Sep 10), Spinach (Sep 10), Radish (Sep 11). |
| October | Direct sow from: Garlic (Oct 13). First frost around October 13. |
| November | Last sowing dates: Garlic (Nov 3). |
| 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 Westminster, MD (ZIP 21157)?
The median last spring frost date for Westminster, MD (ZIP code 21157) is around April 30. 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 April 13; one in ten it runs past May 15.
What is the first fall frost date in Westminster, MD?
The median first fall frost date for Westminster, MD is around October 13. 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 September 29 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Westminster, MD?
The frost-free growing season in Westminster is about 166 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 Westminster (166 frost-free days, a moderate season), 31 of 56 planner crops fit outright, 24 get two plantings, 1 crop is perennial.
What USDA hardiness zone is Westminster, MD?
Westminster, MD is in USDA hardiness zone 7a (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 Westminster, MD?
Start tomatoes indoors Mar 26 and plant out May 14 in Westminster. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Westminster?
Two: plant Apr 2 and again by Aug 22; both mature before Oct 20.
When do I plant garlic in Westminster?
Oct 13 to Nov 3; it overwinters and is ready the following summer.
Which nearby ZIP has a longer season?
Finksburg (ZIP 21048) has 201 frost-free days, 35 more than Westminster (ZIP 21157). See Finksburg ZIP 21048 frost dates
Nearby and related
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- When to plant Peppers in MD
- When to plant Cucumbers in MD
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- Look up another ZIP