Frost Dates for Princeton, NJ 08540
Last spring frost April 24 · First fall frost October 15 · 174 frost-free days · USDA Zone 7a
ZIP 08540 has about 50,400 people, the largest of 3 ZIP codes in Princeton.
Moderate season: 174 frost-free days. Spring frost risk spans April 13–May 6 (23 days). Fall frost risk spans October 2–October 29 (27 days).
Frost probability for 08540
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | May 6 | April 24 | April 13 |
| Fall (first frost) | October 2 | October 15 | October 29 |
Dates come from NOAA 1971–2000 freeze probabilities at HIGHTSTOWN 2 W (13.4 km away); the 50% date is the median year.
Frost dates by ZIP code in Princeton, NJ
| ZIP | Last spring frost (50%) | First fall frost (50%) | Zone |
|---|---|---|---|
| 08540 | April 24 | October 15 | 7a |
| 08544 | April 24 | October 15 | 7a |
| 08542 | April 24 | October 15 | 7a |
Which crops fit a 174-day season in Princeton
In Princeton (174 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 20 | May 8–May 15 | 132 | fits: 80 days to maturity, 132 available after May 8. | Jun 15 |
| Pepper | Mar 13 | May 8–May 15 | 132 | fits: 75 days to maturity, 132 available after May 8. | Jun 20 |
| Lettuce | Feb 27 | Mar 27–Apr 3 | 209 | two-plantings: Plant Mar 27 and again by Aug 24; both mature before Oct 22. | Aug 24 |
| Carrots | — | Apr 3–Apr 10 | 216 | fits: 70 days to maturity, 216 available after Apr 3. | Aug 13 |
| Cucumber | Apr 3 | May 8–May 15 | 146 | two-plantings: Plant May 8 and again by Jul 19; both mature before Oct 1. | Jul 19 |
| Beans | — | May 1–May 15 | 160 | two-plantings: Plant May 1 and again by Jul 26; both mature before Oct 8. | Jul 26 |
| Peas | — | Feb 27–May 8 | 237 | fits: 65 days to maturity, 237 available after Feb 27. | Aug 4 |
| Zucchini | Apr 10 | May 8–May 15 | 146 | two-plantings: Plant May 8 and again by Jul 24; both mature before Oct 1. | Jul 24 |
| Onion | Jan 30 | Mar 27–Apr 10 | 209 | fits: 100 days to maturity, 209 available after Mar 27. | — |
| Spinach | — | Feb 27–Apr 17 | 251 | two-plantings: Plant Feb 27 and again by Sep 12; both mature before Nov 5. | Sep 12 |
| Kale | Feb 13 | Mar 27–Apr 10 | 223 | two-plantings: Plant Mar 27 and again by Aug 28; both mature before Nov 5. | Aug 28 |
| Broccoli | Feb 27 | Mar 27–Apr 10 | 209 | fits: 80 days to maturity, 209 available after Mar 27. | Jul 20 |
| Cabbage | Feb 27 | Mar 27–Apr 10 | 223 | fits: 70 days to maturity, 223 available after Mar 27. | Aug 13 |
| Radish | — | Feb 27–May 22 | 237 | two-plantings: Plant Feb 27 and again by Sep 13; both mature before Oct 22. | Sep 13 |
| Beets | — | Feb 27–May 22 | 237 | two-plantings: Plant Feb 27 and again by Aug 14; both mature before Oct 22. | Aug 14 |
| Potatoes | — | Apr 10–Apr 17 | 195 | fits: 90 days to maturity, 195 available after Apr 10. | — |
| Garlic | — | Oct 15 | 279 | overwinter: Plant Oct 15 to Nov 5; harvest the following summer. | Nov 5 |
| Strawberry | — | Mar 20–May 15 | 230 | perennial: A perennial: plant Mar 20; it fruits from the following year and keeps producing for several years. | — |
| Corn | Mar 27 | May 1–May 8 | 146 | fits: 75 days to maturity, 146 available after May 1. | Jun 27 |
| Pumpkin | Apr 10 | May 8–May 8 | 139 | fits: 100 days to maturity, 139 available after May 8. | Jun 2 |
| Cauliflower | Mar 13 | Apr 17–May 1 | 188 | fits: 75 days to maturity, 188 available after Apr 17. | Jul 25 |
| Swiss Chard | Feb 27 | Apr 10–Apr 10 | 195 | two-plantings: Plant Apr 10 and again by Aug 14; both mature before Oct 22. | Aug 14 |
| Arugula | — | Feb 27–May 22 | 251 | two-plantings: Plant Feb 27 and again by Sep 12; both mature before Nov 5. | Sep 12 |
| Brussel Sprouts | Feb 27 | Mar 27–Apr 10 | 223 | fits: 100 days to maturity, 223 available after Mar 27. | Jul 14 |
| Butternut Squash | Apr 10 | May 8–May 15 | 139 | fits: 100 days to maturity, 139 available after May 8. | Jun 2 |
| Eggplant | Mar 6 | May 8–May 15 | 132 | fits: 70 days to maturity, 132 available after May 8. | Jun 25 |
| Okra | Mar 27 | May 1–May 8 | 153 | two-plantings: Plant May 1 and again by Jul 24; both mature before Oct 1. | Jul 24 |
| Basil | Mar 20 | May 15–May 15 | 139 | two-plantings: Plant May 15 and again by Jul 19; both mature before Oct 1. | Jul 19 |
| Cilantro | — | Mar 27–Apr 17 | 209 | two-plantings: Plant Mar 27 and again by Aug 19; both mature before Oct 22. | Aug 19 |
| Parsley | Feb 13 | May 1–May 8 | 174 | fits: 70 days to maturity, 174 available after May 1. | Jul 30 |
| Celery | Feb 13 | May 1–May 15 | 174 | fits: 120 days to maturity, 174 available after May 1. | Jun 10 |
| Scallions | Feb 13 | Mar 27–Apr 10 | 223 | two-plantings: Plant Mar 27 and again by Aug 23; both mature before Nov 5. | Aug 23 |
| Turnip | — | Mar 27–Apr 10 | 223 | two-plantings: Plant Mar 27 and again by Sep 2; both mature before Nov 5. | Sep 2 |
| Kohlrabi | — | Mar 13–Mar 27 | 237 | two-plantings: Plant Mar 13 and again by Aug 28; both mature before Nov 5. | Aug 28 |
| Bok Choy | Mar 27 | Apr 17–Apr 24 | 188 | two-plantings: Plant Apr 17 and again by Aug 24; both mature before Oct 22. | Aug 24 |
| Collards | Feb 13 | Mar 27–Apr 10 | 223 | two-plantings: Plant Mar 27 and again by Aug 23; both mature before Nov 5. | Aug 23 |
| Cantaloupe | Apr 10 | May 8–May 15 | 132 | fits: 85 days to maturity, 132 available after May 8. | Jun 10 |
| Chives | Jan 30 | May 1–May 8 | 188 | fits: 90 days to maturity, 188 available after May 1. | — |
| Dill | — | Feb 27–May 22 | 237 | two-plantings: Plant Feb 27 and again by Aug 14; both mature before Oct 22. | Aug 14 |
| Oregano | Feb 13 | May 1–May 8 | 188 | fits: 80 days to maturity, 188 available after May 1. | — |
| Rosemary | Jan 30 | May 1–May 8 | 174 | fits: 80 days to maturity, 174 available after May 1. | — |
| Sage | Feb 27 | May 1–May 8 | 188 | fits: 75 days to maturity, 188 available after May 1. | — |
| Thyme | Feb 13 | May 1–May 8 | 188 | fits: 90 days to maturity, 188 available after May 1. | — |
| Calendula | Mar 13 | Apr 10–Apr 24 | 195 | two-plantings: Plant Apr 10 and again by Aug 19; both mature before Oct 22. | Aug 19 |
| Cosmos | Mar 27 | Apr 24–May 8 | 160 | two-plantings: Plant Apr 24 and again by Jul 19; both mature before Oct 1. | Jul 19 |
| Lavender | Jan 30 | Apr 24–May 8 | 195 | fits: 90 days to maturity, 195 available after Apr 24. | — |
| Marigolds | Mar 13 | Apr 24–May 1 | 160 | two-plantings: Plant Apr 24 and again by Jul 29; both mature before Oct 1. | Jul 29 |
| Melons | Apr 10 | May 8–May 15 | 132 | fits: 85 days to maturity, 132 available after May 8. | Jun 10 |
| Mint | — | Apr 24–May 8 | 195 | fits: 90 days to maturity, 195 available after Apr 24. | — |
| Nasturtiums | Mar 27 | Apr 24–May 1 | 160 | two-plantings: Plant Apr 24 and again by Jul 24; both mature before Oct 1. | Jul 24 |
| Pole Beans | — | May 1–May 15 | 153 | fits: 65 days to maturity, 153 available after May 1. | Jul 14 |
| Spaghetti Squash | Apr 10 | May 8–May 15 | 139 | fits: 90 days to maturity, 139 available after May 8. | Jun 12 |
| Sunflowers | — | Apr 24–May 8 | 160 | fits: 70 days to maturity, 160 available after Apr 24. | Jul 9 |
| Tomatillos | Feb 27 | May 1–May 8 | 139 | fits: 75 days to maturity, 139 available after May 1. | Jun 20 |
| Watermelon | Apr 10 | May 1–May 8 | 139 | fits: 80 days to maturity, 139 available after May 1. | Jun 15 |
| Yellow Squash | Apr 10 | May 8–May 15 | 146 | two-plantings: Plant May 8 and again by Jul 24; both mature before Oct 1. | Jul 24 |
| Zinnias | Mar 27 | Apr 24–May 8 | 160 | two-plantings: Plant Apr 24 and again by Jul 19; both mature before Oct 1. | Jul 19 |
Month by month in Princeton
| Month | What to do |
|---|---|
| January | Start indoors: Chives (Jan 30), Lavender (Jan 30), Onion (Jan 30), Rosemary (Jan 30). |
| February | Start indoors: Celery (Feb 13), Collards (Feb 13), Kale (Feb 13), Oregano (Feb 13), Parsley (Feb 13), Scallions (Feb 13), +8 more. Direct sow from: Arugula (Feb 27), Beets (Feb 27), Dill (Feb 27), Peas (Feb 27), Radish (Feb 27), Spinach (Feb 27). |
| March | Start indoors: Eggplant (Mar 6), Calendula (Mar 13), Cauliflower (Mar 13), Marigolds (Mar 13), Pepper (Mar 13), Basil (Mar 20), +7 more. Direct sow from: Kohlrabi (Mar 13), Cilantro (Mar 27), Turnip (Mar 27). Transplant from: Broccoli (Mar 27), Brussel Sprouts (Mar 27), Cabbage (Mar 27), Collards (Mar 27), Kale (Mar 27), Lettuce (Mar 27), +2 more. Plant: Strawberry (Mar 20). |
| April | Start indoors: Cucumber (Apr 3), Butternut Squash (Apr 10), Cantaloupe (Apr 10), Melons (Apr 10), Pumpkin (Apr 10), Spaghetti Squash (Apr 10), +3 more. Direct sow from: Carrots (Apr 3), Potatoes (Apr 10), Sunflowers (Apr 24). Transplant from: Calendula (Apr 10), Swiss Chard (Apr 10), Bok Choy (Apr 17), Cauliflower (Apr 17), Cosmos (Apr 24), Lavender (Apr 24), +4 more. Last frost around April 24. |
| May | Direct sow from: Beans (May 1), Pole Beans (May 1). Transplant from: Celery (May 1), Chives (May 1), Corn (May 1), Okra (May 1), Oregano (May 1), Parsley (May 1), +17 more. |
| June | Last sowing dates: Butternut Squash (Jun 2), Pumpkin (Jun 2), Cantaloupe (Jun 10), Celery (Jun 10), Melons (Jun 10), Spaghetti Squash (Jun 12), +6 more. |
| July | Last sowing dates: Sunflowers (Jul 9), Brussel Sprouts (Jul 14), Pole Beans (Jul 14), Basil (Jul 19), Cosmos (Jul 19), Cucumber (Jul 19), +10 more. |
| August | Last sowing dates: Peas (Aug 4), Cabbage (Aug 13), Carrots (Aug 13), Beets (Aug 14), Dill (Aug 14), Swiss Chard (Aug 14), +8 more. |
| September | Last sowing dates: Turnip (Sep 2), Arugula (Sep 12), Spinach (Sep 12), Radish (Sep 13). |
| October | Direct sow from: Garlic (Oct 15). First frost around October 15. |
| November | Last sowing dates: Garlic (Nov 5). |
| 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 Princeton, NJ (ZIP 08540)?
The median last spring frost date for Princeton, NJ (ZIP code 08540) is around April 24. 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 6.
What is the first fall frost date in Princeton, NJ?
The median first fall frost date for Princeton, NJ is around October 15. 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 Princeton, NJ?
The frost-free growing season in Princeton is about 174 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 Princeton (174 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 Princeton, NJ?
Princeton, NJ 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 Princeton, NJ?
Start tomatoes indoors Mar 20 and plant out May 8 in Princeton. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Princeton?
Two: plant Mar 27 and again by Aug 24; both mature before Oct 22.
When do I plant garlic in Princeton?
Oct 15 to Nov 5; it overwinters and is ready the following summer.
Nearby and related
- Frost dates for Plainsboro, NJ 08536 (4.3 mi)
- Frost dates for Belle Mead, NJ 08502 (5.8 mi)
- Frost dates for Princeton Junction, NJ 08550 (6.1 mi)
- Frost dates for Monmouth Junction, NJ 08852 (6.1 mi)
- Frost dates for Lawrence Township, NJ 08648 (6.5 mi)
- When to plant in NJ
- When to plant Peppers in NJ
- When to plant Cucumbers in NJ
- When to plant Zucchini in NJ
- When to plant Butternut Squash in NJ
- When to plant Basil in NJ
- When to plant Sweet Corn in NJ
- Look up another ZIP