Frost Dates for Princeton, IL 61356
Last spring frost April 27 · First fall frost October 7 · 163 frost-free days · USDA Zone 5b
ZIP 61356 has about 10,800 people.
Moderate season: 163 frost-free days. Spring frost risk spans April 11–May 14 (33 days). Fall frost risk spans September 23–October 21 (28 days).
Frost probability for 61356
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | May 14 | April 27 | April 11 |
| Fall (first frost) | September 23 | October 7 | October 21 |
Dates come from NOAA 1971–2000 freeze probabilities at PERU (27.6 km away); the 50% date is the median year.
Which crops fit a 163-day season in Princeton
In Princeton (163 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 23 | May 11–May 18 | 121 | fits: 80 days to maturity, 121 available after May 11. | Jun 7 |
| Pepper | Mar 16 | May 11–May 18 | 121 | fits: 75 days to maturity, 121 available after May 11. | Jun 12 |
| Lettuce | Mar 2 | Mar 30–Apr 6 | 198 | two-plantings: Plant Mar 30 and again by Aug 16; both mature before Oct 14. | Aug 16 |
| Carrots | — | Apr 6–Apr 13 | 205 | fits: 70 days to maturity, 205 available after Apr 6. | Aug 5 |
| Cucumber | Apr 6 | May 11–May 18 | 135 | two-plantings: Plant May 11 and again by Jul 11; both mature before Sep 23. | Jul 11 |
| Beans | — | May 4–May 18 | 149 | two-plantings: Plant May 4 and again by Jul 18; both mature before Sep 30. | Jul 18 |
| Peas | — | Mar 2–May 11 | 226 | fits: 65 days to maturity, 226 available after Mar 2. | Jul 27 |
| Zucchini | Apr 13 | May 11–May 18 | 135 | two-plantings: Plant May 11 and again by Jul 16; both mature before Sep 23. | Jul 16 |
| Onion | Feb 2 | Mar 30–Apr 13 | 198 | fits: 100 days to maturity, 198 available after Mar 30. | — |
| Spinach | — | Mar 2–Apr 20 | 240 | two-plantings: Plant Mar 2 and again by Sep 4; both mature before Oct 28. | Sep 4 |
| Kale | Feb 16 | Mar 30–Apr 13 | 212 | two-plantings: Plant Mar 30 and again by Aug 20; both mature before Oct 28. | Aug 20 |
| Broccoli | Mar 2 | Mar 30–Apr 13 | 198 | fits: 80 days to maturity, 198 available after Mar 30. | Jul 12 |
| Cabbage | Mar 2 | Mar 30–Apr 13 | 212 | fits: 70 days to maturity, 212 available after Mar 30. | Aug 5 |
| Radish | — | Mar 2–May 25 | 226 | two-plantings: Plant Mar 2 and again by Sep 5; both mature before Oct 14. | Sep 5 |
| Beets | — | Mar 2–May 25 | 226 | two-plantings: Plant Mar 2 and again by Aug 6; both mature before Oct 14. | Aug 6 |
| Potatoes | — | Apr 13–Apr 20 | 184 | fits: 90 days to maturity, 184 available after Apr 13. | — |
| Garlic | — | Oct 7 | 268 | overwinter: Plant Oct 7 to Oct 28; harvest the following summer. | Oct 28 |
| Strawberry | — | Mar 23–May 18 | 219 | perennial: A perennial: plant Mar 23; it fruits from the following year and keeps producing for several years. | — |
| Corn | Mar 30 | May 4–May 11 | 135 | fits: 75 days to maturity, 135 available after May 4. | Jun 19 |
| Pumpkin | Apr 13 | May 11–May 11 | 128 | fits: 100 days to maturity, 128 available after May 11. | May 25 |
| Cauliflower | Mar 16 | Apr 20–May 4 | 177 | fits: 75 days to maturity, 177 available after Apr 20. | Jul 17 |
| Swiss Chard | Mar 2 | Apr 13–Apr 13 | 184 | two-plantings: Plant Apr 13 and again by Aug 6; both mature before Oct 14. | Aug 6 |
| Arugula | — | Mar 2–May 25 | 240 | two-plantings: Plant Mar 2 and again by Sep 4; both mature before Oct 28. | Sep 4 |
| Brussel Sprouts | Mar 2 | Mar 30–Apr 13 | 212 | fits: 100 days to maturity, 212 available after Mar 30. | Jul 6 |
| Butternut Squash | Apr 13 | May 11–May 18 | 128 | fits: 100 days to maturity, 128 available after May 11. | May 25 |
| Eggplant | Mar 9 | May 11–May 18 | 121 | fits: 70 days to maturity, 121 available after May 11. | Jun 17 |
| Okra | Mar 30 | May 4–May 11 | 142 | two-plantings: Plant May 4 and again by Jul 16; both mature before Sep 23. | Jul 16 |
| Basil | Mar 23 | May 18–May 18 | 128 | fits: 60 days to maturity, 128 available after May 18. | Jul 11 |
| Cilantro | — | Mar 30–Apr 20 | 198 | two-plantings: Plant Mar 30 and again by Aug 11; both mature before Oct 14. | Aug 11 |
| Parsley | Feb 16 | May 4–May 11 | 163 | fits: 70 days to maturity, 163 available after May 4. | Jul 22 |
| Celery | Feb 16 | May 4–May 18 | 163 | fits: 120 days to maturity, 163 available after May 4. | Jun 2 |
| Scallions | Feb 16 | Mar 30–Apr 13 | 212 | two-plantings: Plant Mar 30 and again by Aug 15; both mature before Oct 28. | Aug 15 |
| Turnip | — | Mar 30–Apr 13 | 212 | two-plantings: Plant Mar 30 and again by Aug 25; both mature before Oct 28. | Aug 25 |
| Kohlrabi | — | Mar 16–Mar 30 | 226 | two-plantings: Plant Mar 16 and again by Aug 20; both mature before Oct 28. | Aug 20 |
| Bok Choy | Mar 30 | Apr 20–Apr 27 | 177 | two-plantings: Plant Apr 20 and again by Aug 16; both mature before Oct 14. | Aug 16 |
| Collards | Feb 16 | Mar 30–Apr 13 | 212 | two-plantings: Plant Mar 30 and again by Aug 15; both mature before Oct 28. | Aug 15 |
| Cantaloupe | Apr 13 | May 11–May 18 | 121 | fits: 85 days to maturity, 121 available after May 11. | Jun 2 |
| Chives | Feb 2 | May 4–May 11 | 177 | fits: 90 days to maturity, 177 available after May 4. | — |
| Dill | — | Mar 2–May 25 | 226 | two-plantings: Plant Mar 2 and again by Aug 6; both mature before Oct 14. | Aug 6 |
| Oregano | Feb 16 | May 4–May 11 | 177 | fits: 80 days to maturity, 177 available after May 4. | — |
| Rosemary | Feb 2 | May 4–May 11 | 163 | fits: 80 days to maturity, 163 available after May 4. | — |
| Sage | Mar 2 | May 4–May 11 | 177 | fits: 75 days to maturity, 177 available after May 4. | — |
| Thyme | Feb 16 | May 4–May 11 | 177 | fits: 90 days to maturity, 177 available after May 4. | — |
| Calendula | Mar 16 | Apr 13–Apr 27 | 184 | two-plantings: Plant Apr 13 and again by Aug 11; both mature before Oct 14. | Aug 11 |
| Cosmos | Mar 30 | Apr 27–May 11 | 149 | two-plantings: Plant Apr 27 and again by Jul 11; both mature before Sep 23. | Jul 11 |
| Lavender | Feb 2 | Apr 27–May 11 | 184 | fits: 90 days to maturity, 184 available after Apr 27. | — |
| Marigolds | Mar 16 | Apr 27–May 4 | 149 | two-plantings: Plant Apr 27 and again by Jul 21; both mature before Sep 23. | Jul 21 |
| Melons | Apr 13 | May 11–May 18 | 121 | fits: 85 days to maturity, 121 available after May 11. | Jun 2 |
| Mint | — | Apr 27–May 11 | 184 | fits: 90 days to maturity, 184 available after Apr 27. | — |
| Nasturtiums | Mar 30 | Apr 27–May 4 | 149 | two-plantings: Plant Apr 27 and again by Jul 16; both mature before Sep 23. | Jul 16 |
| Pole Beans | — | May 4–May 18 | 142 | fits: 65 days to maturity, 142 available after May 4. | Jul 6 |
| Spaghetti Squash | Apr 13 | May 11–May 18 | 128 | fits: 90 days to maturity, 128 available after May 11. | Jun 4 |
| Sunflowers | — | Apr 27–May 11 | 149 | fits: 70 days to maturity, 149 available after Apr 27. | Jul 1 |
| Tomatillos | Mar 2 | May 4–May 11 | 128 | fits: 75 days to maturity, 128 available after May 4. | Jun 12 |
| Watermelon | Apr 13 | May 4–May 11 | 128 | fits: 80 days to maturity, 128 available after May 4. | Jun 7 |
| Yellow Squash | Apr 13 | May 11–May 18 | 135 | two-plantings: Plant May 11 and again by Jul 16; both mature before Sep 23. | Jul 16 |
| Zinnias | Mar 30 | Apr 27–May 11 | 149 | two-plantings: Plant Apr 27 and again by Jul 11; both mature before Sep 23. | Jul 11 |
Month by month in Princeton
| Month | What to do |
|---|---|
| January | Plan your garden layout and order seeds. Research varieties suited to your frost dates. |
| February | Start indoors: Chives (Feb 2), Lavender (Feb 2), Onion (Feb 2), Rosemary (Feb 2), Celery (Feb 16), Collards (Feb 16), +5 more. |
| March | Start indoors: Broccoli (Mar 2), Brussel Sprouts (Mar 2), Cabbage (Mar 2), Lettuce (Mar 2), Sage (Mar 2), Swiss Chard (Mar 2), +14 more. Direct sow from: Arugula (Mar 2), Beets (Mar 2), Dill (Mar 2), Peas (Mar 2), Radish (Mar 2), Spinach (Mar 2), +3 more. Transplant from: Broccoli (Mar 30), Brussel Sprouts (Mar 30), Cabbage (Mar 30), Collards (Mar 30), Kale (Mar 30), Lettuce (Mar 30), +2 more. Plant: Strawberry (Mar 23). |
| April | Start indoors: Cucumber (Apr 6), Butternut Squash (Apr 13), Cantaloupe (Apr 13), Melons (Apr 13), Pumpkin (Apr 13), Spaghetti Squash (Apr 13), +3 more. Direct sow from: Carrots (Apr 6), Potatoes (Apr 13), Sunflowers (Apr 27). Transplant from: Calendula (Apr 13), Swiss Chard (Apr 13), Bok Choy (Apr 20), Cauliflower (Apr 20), Cosmos (Apr 27), Lavender (Apr 27), +4 more. Last frost around April 27. |
| May | Direct sow from: Beans (May 4), Pole Beans (May 4). Transplant from: Celery (May 4), Chives (May 4), Corn (May 4), Okra (May 4), Oregano (May 4), Parsley (May 4), +17 more. Last sowing dates: Butternut Squash (May 25), Pumpkin (May 25). |
| June | Last sowing dates: Cantaloupe (Jun 2), Celery (Jun 2), Melons (Jun 2), Spaghetti Squash (Jun 4), Tomato (Jun 7), Watermelon (Jun 7), +4 more. |
| July | Last sowing dates: Sunflowers (Jul 1), Brussel Sprouts (Jul 6), Pole Beans (Jul 6), Basil (Jul 11), Cosmos (Jul 11), Cucumber (Jul 11), +11 more. |
| August | Last sowing dates: Cabbage (Aug 5), Carrots (Aug 5), Beets (Aug 6), Dill (Aug 6), Swiss Chard (Aug 6), Calendula (Aug 11), +8 more. |
| September | Last sowing dates: Arugula (Sep 4), Spinach (Sep 4), Radish (Sep 5). |
| October | Direct sow from: Garlic (Oct 7). First frost around October 7. Last sowing dates: Garlic (Oct 28). |
| November | Harvest remaining cold-hardy crops: kale, carrots, and beets. Plant garlic bulbs for next year. |
| 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, IL (ZIP 61356)?
The median last spring frost date for Princeton, IL (ZIP code 61356) is around April 27. 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 11; one in ten it runs past May 14.
What is the first fall frost date in Princeton, IL?
The median first fall frost date for Princeton, IL is around October 7. 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 23 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Princeton, IL?
The frost-free growing season in Princeton is about 163 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 (163 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 Princeton, IL?
Princeton, IL is in USDA hardiness zone 5b (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, IL?
Start tomatoes indoors Mar 23 and plant out May 11 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 30 and again by Aug 16; both mature before Oct 14.
When do I plant garlic in Princeton?
Oct 7 to Oct 28; it overwinters and is ready the following summer.
Which nearby ZIP has a longer season?
Kewanee (ZIP 61443) has 174 frost-free days, 11 more than Princeton (ZIP 61356). See Kewanee ZIP 61443 frost dates
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