Frost Dates for Mechanicsburg, PA 17055
Last spring frost April 23 · First fall frost October 19 · 179 frost-free days · USDA Zone 7a
ZIP 17055 has about 42,000 people, one of 2 ZIP codes in Mechanicsburg.
Moderate season: 179 frost-free days. Spring frost risk spans April 8–May 11 (33 days). Fall frost risk spans October 2–November 3 (32 days).
Frost probability for 17055
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | May 11 | April 23 | April 8 |
| Fall (first frost) | October 2 | October 19 | November 3 |
Dates come from NOAA 1971–2000 freeze probabilities at BLOSERVILLE 1 N (32.5 km away); the 50% date is the median year.
Which crops fit a 179-day season in Mechanicsburg
In Mechanicsburg (179 frost-free days, a moderate 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 19 | May 7–May 14 | 137 | fits: 80 days to maturity, 137 available after May 7. | Jun 19 |
| Pepper | Mar 12 | May 7–May 14 | 137 | fits: 75 days to maturity, 137 available after May 7. | Jun 24 |
| Lettuce | Feb 26 | Mar 26–Apr 2 | 214 | two-plantings: Plant Mar 26 and again by Aug 28; both mature before Oct 26. | Aug 28 |
| Carrots | — | Apr 2–Apr 9 | 221 | fits: 70 days to maturity, 221 available after Apr 2. | Aug 17 |
| Cucumber | Apr 2 | May 7–May 14 | 151 | two-plantings: Plant May 7 and again by Jul 23; both mature before Oct 5. | Jul 23 |
| Beans | — | Apr 30–May 14 | 165 | two-plantings: Plant Apr 30 and again by Jul 30; both mature before Oct 12. | Jul 30 |
| Peas | — | Feb 26–May 7 | 242 | fits: 65 days to maturity, 242 available after Feb 26. | Aug 8 |
| Zucchini | Apr 9 | May 7–May 14 | 151 | two-plantings: Plant May 7 and again by Jul 28; both mature before Oct 5. | Jul 28 |
| Onion | Jan 29 | Mar 26–Apr 9 | 214 | fits: 100 days to maturity, 214 available after Mar 26. | — |
| Spinach | — | Feb 26–Apr 16 | 256 | two-plantings: Plant Feb 26 and again by Sep 16; both mature before Nov 9. | Sep 16 |
| Kale | Feb 12 | Mar 26–Apr 9 | 228 | two-plantings: Plant Mar 26 and again by Sep 1; both mature before Nov 9. | Sep 1 |
| Broccoli | Feb 26 | Mar 26–Apr 9 | 214 | fits: 80 days to maturity, 214 available after Mar 26. | Jul 24 |
| Cabbage | Feb 26 | Mar 26–Apr 9 | 228 | fits: 70 days to maturity, 228 available after Mar 26. | Aug 17 |
| Radish | — | Feb 26–May 21 | 242 | two-plantings: Plant Feb 26 and again by Sep 17; both mature before Oct 26. | Sep 17 |
| Beets | — | Feb 26–May 21 | 242 | two-plantings: Plant Feb 26 and again by Aug 18; both mature before Oct 26. | Aug 18 |
| Potatoes | — | Apr 9–Apr 16 | 200 | fits: 90 days to maturity, 200 available after Apr 9. | — |
| Garlic | — | Oct 19 | 284 | overwinter: Plant Oct 19 to Nov 9; harvest the following summer. | Nov 9 |
| Strawberry | — | Mar 19–May 14 | 235 | perennial: A perennial: plant Mar 19; it fruits from the following year and keeps producing for several years. | — |
| Corn | Mar 26 | Apr 30–May 7 | 151 | fits: 75 days to maturity, 151 available after Apr 30. | Jul 1 |
| Pumpkin | Apr 9 | May 7–May 7 | 144 | fits: 100 days to maturity, 144 available after May 7. | Jun 6 |
| Cauliflower | Mar 12 | Apr 16–Apr 30 | 193 | fits: 75 days to maturity, 193 available after Apr 16. | Jul 29 |
| Swiss Chard | Feb 26 | Apr 9–Apr 9 | 200 | two-plantings: Plant Apr 9 and again by Aug 18; both mature before Oct 26. | Aug 18 |
| Arugula | — | Feb 26–May 21 | 256 | two-plantings: Plant Feb 26 and again by Sep 16; both mature before Nov 9. | Sep 16 |
| Brussel Sprouts | Feb 26 | Mar 26–Apr 9 | 228 | fits: 100 days to maturity, 228 available after Mar 26. | Jul 18 |
| Butternut Squash | Apr 9 | May 7–May 14 | 144 | fits: 100 days to maturity, 144 available after May 7. | Jun 6 |
| Eggplant | Mar 5 | May 7–May 14 | 137 | fits: 70 days to maturity, 137 available after May 7. | Jun 29 |
| Okra | Mar 26 | Apr 30–May 7 | 158 | two-plantings: Plant Apr 30 and again by Jul 28; both mature before Oct 5. | Jul 28 |
| Basil | Mar 19 | May 14–May 14 | 144 | two-plantings: Plant May 14 and again by Jul 23; both mature before Oct 5. | Jul 23 |
| Cilantro | — | Mar 26–Apr 16 | 214 | two-plantings: Plant Mar 26 and again by Aug 23; both mature before Oct 26. | Aug 23 |
| Parsley | Feb 12 | Apr 30–May 7 | 179 | fits: 70 days to maturity, 179 available after Apr 30. | Aug 3 |
| Celery | Feb 12 | Apr 30–May 14 | 179 | fits: 120 days to maturity, 179 available after Apr 30. | Jun 14 |
| Scallions | Feb 12 | Mar 26–Apr 9 | 228 | two-plantings: Plant Mar 26 and again by Aug 27; both mature before Nov 9. | Aug 27 |
| Turnip | — | Mar 26–Apr 9 | 228 | two-plantings: Plant Mar 26 and again by Sep 6; both mature before Nov 9. | Sep 6 |
| Kohlrabi | — | Mar 12–Mar 26 | 242 | two-plantings: Plant Mar 12 and again by Sep 1; both mature before Nov 9. | Sep 1 |
| Bok Choy | Mar 26 | Apr 16–Apr 23 | 193 | two-plantings: Plant Apr 16 and again by Aug 28; both mature before Oct 26. | Aug 28 |
| Collards | Feb 12 | Mar 26–Apr 9 | 228 | two-plantings: Plant Mar 26 and again by Aug 27; both mature before Nov 9. | Aug 27 |
| Cantaloupe | Apr 9 | May 7–May 14 | 137 | fits: 85 days to maturity, 137 available after May 7. | Jun 14 |
| Chives | Jan 29 | Apr 30–May 7 | 193 | fits: 90 days to maturity, 193 available after Apr 30. | — |
| Dill | — | Feb 26–May 21 | 242 | two-plantings: Plant Feb 26 and again by Aug 18; both mature before Oct 26. | Aug 18 |
| Oregano | Feb 12 | Apr 30–May 7 | 193 | fits: 80 days to maturity, 193 available after Apr 30. | — |
| Rosemary | Jan 29 | Apr 30–May 7 | 179 | fits: 80 days to maturity, 179 available after Apr 30. | — |
| Sage | Feb 26 | Apr 30–May 7 | 193 | fits: 75 days to maturity, 193 available after Apr 30. | — |
| Thyme | Feb 12 | Apr 30–May 7 | 193 | fits: 90 days to maturity, 193 available after Apr 30. | — |
| Calendula | Mar 12 | Apr 9–Apr 23 | 200 | two-plantings: Plant Apr 9 and again by Aug 23; both mature before Oct 26. | Aug 23 |
| Cosmos | Mar 26 | Apr 23–May 7 | 165 | two-plantings: Plant Apr 23 and again by Jul 23; both mature before Oct 5. | Jul 23 |
| Lavender | Jan 29 | Apr 23–May 7 | 200 | fits: 90 days to maturity, 200 available after Apr 23. | — |
| Marigolds | Mar 12 | Apr 23–Apr 30 | 165 | two-plantings: Plant Apr 23 and again by Aug 2; both mature before Oct 5. | Aug 2 |
| Melons | Apr 9 | May 7–May 14 | 137 | fits: 85 days to maturity, 137 available after May 7. | Jun 14 |
| Mint | — | Apr 23–May 7 | 200 | fits: 90 days to maturity, 200 available after Apr 23. | — |
| Nasturtiums | Mar 26 | Apr 23–Apr 30 | 165 | two-plantings: Plant Apr 23 and again by Jul 28; both mature before Oct 5. | Jul 28 |
| Pole Beans | — | Apr 30–May 14 | 158 | fits: 65 days to maturity, 158 available after Apr 30. | Jul 18 |
| Spaghetti Squash | Apr 9 | May 7–May 14 | 144 | fits: 90 days to maturity, 144 available after May 7. | Jun 16 |
| Sunflowers | — | Apr 23–May 7 | 165 | fits: 70 days to maturity, 165 available after Apr 23. | Jul 13 |
| Tomatillos | Feb 26 | Apr 30–May 7 | 144 | fits: 75 days to maturity, 144 available after Apr 30. | Jun 24 |
| Watermelon | Apr 9 | Apr 30–May 7 | 144 | fits: 80 days to maturity, 144 available after Apr 30. | Jun 19 |
| Yellow Squash | Apr 9 | May 7–May 14 | 151 | two-plantings: Plant May 7 and again by Jul 28; both mature before Oct 5. | Jul 28 |
| Zinnias | Mar 26 | Apr 23–May 7 | 165 | two-plantings: Plant Apr 23 and again by Jul 23; both mature before Oct 5. | Jul 23 |
Month by month in Mechanicsburg
| Month | What to do |
|---|---|
| January | Start indoors: Chives (Jan 29), Lavender (Jan 29), Onion (Jan 29), Rosemary (Jan 29). |
| February | Start indoors: Celery (Feb 12), Collards (Feb 12), Kale (Feb 12), Oregano (Feb 12), Parsley (Feb 12), Scallions (Feb 12), +8 more. Direct sow from: Arugula (Feb 26), Beets (Feb 26), Dill (Feb 26), Peas (Feb 26), Radish (Feb 26), Spinach (Feb 26). |
| March | Start indoors: Eggplant (Mar 5), Calendula (Mar 12), Cauliflower (Mar 12), Marigolds (Mar 12), Pepper (Mar 12), Basil (Mar 19), +7 more. Direct sow from: Kohlrabi (Mar 12), Cilantro (Mar 26), Turnip (Mar 26). Transplant from: Broccoli (Mar 26), Brussel Sprouts (Mar 26), Cabbage (Mar 26), Collards (Mar 26), Kale (Mar 26), Lettuce (Mar 26), +2 more. Plant: Strawberry (Mar 19). |
| April | Start indoors: Cucumber (Apr 2), Butternut Squash (Apr 9), Cantaloupe (Apr 9), Melons (Apr 9), Pumpkin (Apr 9), Spaghetti Squash (Apr 9), +3 more. Direct sow from: Carrots (Apr 2), Potatoes (Apr 9), Sunflowers (Apr 23), Beans (Apr 30), Pole Beans (Apr 30). Transplant from: Calendula (Apr 9), Swiss Chard (Apr 9), Bok Choy (Apr 16), Cauliflower (Apr 16), Cosmos (Apr 23), Lavender (Apr 23), +15 more. Last frost around April 23. |
| May | Transplant from: Butternut Squash (May 7), Cantaloupe (May 7), Cucumber (May 7), Eggplant (May 7), Melons (May 7), Pepper (May 7), +6 more. |
| June | Last sowing dates: Butternut Squash (Jun 6), Pumpkin (Jun 6), Cantaloupe (Jun 14), Celery (Jun 14), Melons (Jun 14), Spaghetti Squash (Jun 16), +5 more. |
| July | Last sowing dates: Corn (Jul 1), Sunflowers (Jul 13), Brussel Sprouts (Jul 18), Pole Beans (Jul 18), Basil (Jul 23), Cosmos (Jul 23), +9 more. |
| August | Last sowing dates: Marigolds (Aug 2), Parsley (Aug 3), Peas (Aug 8), Cabbage (Aug 17), Carrots (Aug 17), Beets (Aug 18), +8 more. |
| September | Last sowing dates: Kale (Sep 1), Kohlrabi (Sep 1), Turnip (Sep 6), Arugula (Sep 16), Spinach (Sep 16), Radish (Sep 17). |
| October | Direct sow from: Garlic (Oct 19). First frost around October 19. |
| November | Last sowing dates: Garlic (Nov 9). |
| 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 Mechanicsburg, PA (ZIP 17055)?
The median last spring frost date for Mechanicsburg, PA (ZIP code 17055) is around April 23. 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 8; one in ten it runs past May 11.
What is the first fall frost date in Mechanicsburg, PA?
The median first fall frost date for Mechanicsburg, PA is around October 19. 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 2 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Mechanicsburg, PA?
The frost-free growing season in Mechanicsburg is about 179 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 Mechanicsburg (179 frost-free days, a moderate season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.
What USDA hardiness zone is Mechanicsburg, PA?
Mechanicsburg, PA 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 Mechanicsburg, PA?
Start tomatoes indoors Mar 19 and plant out May 7 in Mechanicsburg. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Mechanicsburg?
Two: plant Mar 26 and again by Aug 28; both mature before Oct 26.
When do I plant garlic in Mechanicsburg?
Oct 19 to Nov 9; it overwinters and is ready the following summer.
Nearby and related
- Frost dates for Mechanicsburg, PA 17050 (5.2 mi)
- Frost dates for Camp Hill, PA 17011 (5.4 mi)
- Frost dates for Dillsburg, PA 17019 (6.2 mi)
- Frost dates for New Cumberland, PA 17070 (7.3 mi)
- Frost dates for Enola, PA 17025 (8.2 mi)
- When to plant in PA
- When to plant Peppers in PA
- When to plant Cucumbers in PA
- When to plant Zucchini in PA
- When to plant Butternut Squash in PA
- When to plant Basil in PA
- When to plant Sweet Corn in PA
- Look up another ZIP