Frost Dates for Knox, IN 46534
Last spring frost April 28 · First fall frost October 13 · 168 frost-free days · USDA Zone 5b
ZIP 46534 has about 10,800 people.
Moderate season: 168 frost-free days. Spring frost risk spans April 11–May 15 (34 days). Fall frost risk spans September 30–October 25 (25 days).
Frost probability for 46534
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | May 15 | April 28 | April 11 |
| Fall (first frost) | September 30 | October 13 | October 25 |
Dates come from NOAA 1971–2000 freeze probabilities at WINAMAC 2SSE (28.9 km away); the 50% date is the median year.
Which crops fit a 168-day season in Knox
In Knox (168 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 24 | May 12–May 19 | 126 | fits: 80 days to maturity, 126 available after May 12. | Jun 13 |
| Pepper | Mar 17 | May 12–May 19 | 126 | fits: 75 days to maturity, 126 available after May 12. | Jun 18 |
| Lettuce | Mar 3 | Mar 31–Apr 7 | 203 | two-plantings: Plant Mar 31 and again by Aug 22; both mature before Oct 20. | Aug 22 |
| Carrots | — | Apr 7–Apr 14 | 210 | fits: 70 days to maturity, 210 available after Apr 7. | Aug 11 |
| Cucumber | Apr 7 | May 12–May 19 | 140 | two-plantings: Plant May 12 and again by Jul 17; both mature before Sep 29. | Jul 17 |
| Beans | — | May 5–May 19 | 154 | two-plantings: Plant May 5 and again by Jul 24; both mature before Oct 6. | Jul 24 |
| Peas | — | Mar 3–May 12 | 231 | fits: 65 days to maturity, 231 available after Mar 3. | Aug 2 |
| Zucchini | Apr 14 | May 12–May 19 | 140 | two-plantings: Plant May 12 and again by Jul 22; both mature before Sep 29. | Jul 22 |
| Onion | Feb 3 | Mar 31–Apr 14 | 203 | fits: 100 days to maturity, 203 available after Mar 31. | — |
| Spinach | — | Mar 3–Apr 21 | 245 | two-plantings: Plant Mar 3 and again by Sep 10; both mature before Nov 3. | Sep 10 |
| Kale | Feb 17 | Mar 31–Apr 14 | 217 | two-plantings: Plant Mar 31 and again by Aug 26; both mature before Nov 3. | Aug 26 |
| Broccoli | Mar 3 | Mar 31–Apr 14 | 203 | fits: 80 days to maturity, 203 available after Mar 31. | Jul 18 |
| Cabbage | Mar 3 | Mar 31–Apr 14 | 217 | fits: 70 days to maturity, 217 available after Mar 31. | Aug 11 |
| Radish | — | Mar 3–May 26 | 231 | two-plantings: Plant Mar 3 and again by Sep 11; both mature before Oct 20. | Sep 11 |
| Beets | — | Mar 3–May 26 | 231 | two-plantings: Plant Mar 3 and again by Aug 12; both mature before Oct 20. | Aug 12 |
| Potatoes | — | Apr 14–Apr 21 | 189 | fits: 90 days to maturity, 189 available after Apr 14. | — |
| Garlic | — | Oct 13 | 273 | overwinter: Plant Oct 13 to Nov 3; harvest the following summer. | Nov 3 |
| Strawberry | — | Mar 24–May 19 | 224 | perennial: A perennial: plant Mar 24; it fruits from the following year and keeps producing for several years. | — |
| Corn | Mar 31 | May 5–May 12 | 140 | fits: 75 days to maturity, 140 available after May 5. | Jun 25 |
| Pumpkin | Apr 14 | May 12–May 12 | 133 | fits: 100 days to maturity, 133 available after May 12. | May 31 |
| Cauliflower | Mar 17 | Apr 21–May 5 | 182 | fits: 75 days to maturity, 182 available after Apr 21. | Jul 23 |
| Swiss Chard | Mar 3 | Apr 14–Apr 14 | 189 | two-plantings: Plant Apr 14 and again by Aug 12; both mature before Oct 20. | Aug 12 |
| Arugula | — | Mar 3–May 26 | 245 | two-plantings: Plant Mar 3 and again by Sep 10; both mature before Nov 3. | Sep 10 |
| Brussel Sprouts | Mar 3 | Mar 31–Apr 14 | 217 | fits: 100 days to maturity, 217 available after Mar 31. | Jul 12 |
| Butternut Squash | Apr 14 | May 12–May 19 | 133 | fits: 100 days to maturity, 133 available after May 12. | May 31 |
| Eggplant | Mar 10 | May 12–May 19 | 126 | fits: 70 days to maturity, 126 available after May 12. | Jun 23 |
| Okra | Mar 31 | May 5–May 12 | 147 | two-plantings: Plant May 5 and again by Jul 22; both mature before Sep 29. | Jul 22 |
| Basil | Mar 24 | May 19–May 19 | 133 | fits: 60 days to maturity, 133 available after May 19. | Jul 17 |
| Cilantro | — | Mar 31–Apr 21 | 203 | two-plantings: Plant Mar 31 and again by Aug 17; both mature before Oct 20. | Aug 17 |
| Parsley | Feb 17 | May 5–May 12 | 168 | fits: 70 days to maturity, 168 available after May 5. | Jul 28 |
| Celery | Feb 17 | May 5–May 19 | 168 | fits: 120 days to maturity, 168 available after May 5. | Jun 8 |
| Scallions | Feb 17 | Mar 31–Apr 14 | 217 | two-plantings: Plant Mar 31 and again by Aug 21; both mature before Nov 3. | Aug 21 |
| Turnip | — | Mar 31–Apr 14 | 217 | two-plantings: Plant Mar 31 and again by Aug 31; both mature before Nov 3. | Aug 31 |
| Kohlrabi | — | Mar 17–Mar 31 | 231 | two-plantings: Plant Mar 17 and again by Aug 26; both mature before Nov 3. | Aug 26 |
| Bok Choy | Mar 31 | Apr 21–Apr 28 | 182 | two-plantings: Plant Apr 21 and again by Aug 22; both mature before Oct 20. | Aug 22 |
| Collards | Feb 17 | Mar 31–Apr 14 | 217 | two-plantings: Plant Mar 31 and again by Aug 21; both mature before Nov 3. | Aug 21 |
| Cantaloupe | Apr 14 | May 12–May 19 | 126 | fits: 85 days to maturity, 126 available after May 12. | Jun 8 |
| Chives | Feb 3 | May 5–May 12 | 182 | fits: 90 days to maturity, 182 available after May 5. | — |
| Dill | — | Mar 3–May 26 | 231 | two-plantings: Plant Mar 3 and again by Aug 12; both mature before Oct 20. | Aug 12 |
| Oregano | Feb 17 | May 5–May 12 | 182 | fits: 80 days to maturity, 182 available after May 5. | — |
| Rosemary | Feb 3 | May 5–May 12 | 168 | fits: 80 days to maturity, 168 available after May 5. | — |
| Sage | Mar 3 | May 5–May 12 | 182 | fits: 75 days to maturity, 182 available after May 5. | — |
| Thyme | Feb 17 | May 5–May 12 | 182 | fits: 90 days to maturity, 182 available after May 5. | — |
| Calendula | Mar 17 | Apr 14–Apr 28 | 189 | two-plantings: Plant Apr 14 and again by Aug 17; both mature before Oct 20. | Aug 17 |
| Cosmos | Mar 31 | Apr 28–May 12 | 154 | two-plantings: Plant Apr 28 and again by Jul 17; both mature before Sep 29. | Jul 17 |
| Lavender | Feb 3 | Apr 28–May 12 | 189 | fits: 90 days to maturity, 189 available after Apr 28. | — |
| Marigolds | Mar 17 | Apr 28–May 5 | 154 | two-plantings: Plant Apr 28 and again by Jul 27; both mature before Sep 29. | Jul 27 |
| Melons | Apr 14 | May 12–May 19 | 126 | fits: 85 days to maturity, 126 available after May 12. | Jun 8 |
| Mint | — | Apr 28–May 12 | 189 | fits: 90 days to maturity, 189 available after Apr 28. | — |
| Nasturtiums | Mar 31 | Apr 28–May 5 | 154 | two-plantings: Plant Apr 28 and again by Jul 22; both mature before Sep 29. | Jul 22 |
| Pole Beans | — | May 5–May 19 | 147 | fits: 65 days to maturity, 147 available after May 5. | Jul 12 |
| Spaghetti Squash | Apr 14 | May 12–May 19 | 133 | fits: 90 days to maturity, 133 available after May 12. | Jun 10 |
| Sunflowers | — | Apr 28–May 12 | 154 | fits: 70 days to maturity, 154 available after Apr 28. | Jul 7 |
| Tomatillos | Mar 3 | May 5–May 12 | 133 | fits: 75 days to maturity, 133 available after May 5. | Jun 18 |
| Watermelon | Apr 14 | May 5–May 12 | 133 | fits: 80 days to maturity, 133 available after May 5. | Jun 13 |
| Yellow Squash | Apr 14 | May 12–May 19 | 140 | two-plantings: Plant May 12 and again by Jul 22; both mature before Sep 29. | Jul 22 |
| Zinnias | Mar 31 | Apr 28–May 12 | 154 | two-plantings: Plant Apr 28 and again by Jul 17; both mature before Sep 29. | Jul 17 |
Month by month in Knox
| Month | What to do |
|---|---|
| January | Plan your garden layout and order seeds. Research varieties suited to your frost dates. |
| February | Start indoors: Chives (Feb 3), Lavender (Feb 3), Onion (Feb 3), Rosemary (Feb 3), Celery (Feb 17), Collards (Feb 17), +5 more. |
| March | Start indoors: Broccoli (Mar 3), Brussel Sprouts (Mar 3), Cabbage (Mar 3), Lettuce (Mar 3), Sage (Mar 3), Swiss Chard (Mar 3), +14 more. Direct sow from: Arugula (Mar 3), Beets (Mar 3), Dill (Mar 3), Peas (Mar 3), Radish (Mar 3), Spinach (Mar 3), +3 more. Transplant from: Broccoli (Mar 31), Brussel Sprouts (Mar 31), Cabbage (Mar 31), Collards (Mar 31), Kale (Mar 31), Lettuce (Mar 31), +2 more. Plant: Strawberry (Mar 24). |
| April | Start indoors: Cucumber (Apr 7), Butternut Squash (Apr 14), Cantaloupe (Apr 14), Melons (Apr 14), Pumpkin (Apr 14), Spaghetti Squash (Apr 14), +3 more. Direct sow from: Carrots (Apr 7), Potatoes (Apr 14), Sunflowers (Apr 28). Transplant from: Calendula (Apr 14), Swiss Chard (Apr 14), Bok Choy (Apr 21), Cauliflower (Apr 21), Cosmos (Apr 28), Lavender (Apr 28), +4 more. Last frost around April 28. |
| May | Direct sow from: Beans (May 5), Pole Beans (May 5). Transplant from: Celery (May 5), Chives (May 5), Corn (May 5), Okra (May 5), Oregano (May 5), Parsley (May 5), +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 Knox, IN (ZIP 46534)?
The median last spring frost date for Knox, IN (ZIP code 46534) is around April 28. 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 15.
What is the first fall frost date in Knox, IN?
The median first fall frost date for Knox, IN 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 30 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Knox, IN?
The frost-free growing season in Knox is about 168 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 Knox (168 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 Knox, IN?
Knox, IN 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 Knox, IN?
Start tomatoes indoors Mar 24 and plant out May 12 in Knox. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Knox?
Two: plant Mar 31 and again by Aug 22; both mature before Oct 20.
When do I plant garlic in Knox?
Oct 13 to Nov 3; it overwinters and is ready the following summer.
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