Frost Dates for Portage, IN 46368
Last spring frost May 3 · First fall frost October 13 · 163 frost-free days · USDA Zone 6a
Frost probability for 46368
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | May 17 | May 3 | April 19 |
| Fall (first frost) | September 28 | October 13 | October 29 |
Dates come from NOAA 1971–2000 freeze probabilities at the nearest reporting station (26.0 km away); the 50% date is the median year.
Month by month in Portage
| Month | What to do |
|---|---|
| January | Plan your garden layout and order seeds. Research varieties suited to your frost dates. |
| February | Start the slowest-growing crops indoors: onions, leeks, and celery (10–12 weeks before last frost). |
| March | Start peppers and eggplant indoors 8–10 weeks before your last frost (around May 3). Start tomatoes about two weeks later, 6–8 weeks before last frost. |
| April | Start herbs, basil, and squash indoors (4–6 weeks before frost). Direct sow peas, spinach, and lettuce if soil is workable. |
| May | Last frost around May 3. Transplant cold-hardy crops (broccoli, kale, cabbage). Harden off tomato and pepper seedlings. |
| June | Frost has passed. Transplant tomatoes, peppers, and basil outdoors. Direct sow beans, cucumbers, squash, and zucchini. |
| July | Succession plant lettuce and greens. Keep beds weeded and watered consistently. |
| August | Harvest regularly to encourage production. Monitor for pests and disease. |
| September | First fall frost approaching (around October 13). Transplant fall brassicas. Sow spinach, arugula, and radishes. |
| October | First frost around October 13. Harvest tomatoes and peppers before frost. Cover cold-hardy crops with row covers to extend the season. |
| 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. |
What grows in a 163-day season
Frequently Asked Questions
What is the last frost date for Portage, IN (ZIP 46368)?
The median last spring frost date for Portage, IN (ZIP code 46368) is around May 3. 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.
What is the first fall frost date in Portage, IN?
The median first fall frost date for Portage, 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.
How long is the growing season in Portage, IN?
The frost-free growing season in Portage 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.
What USDA hardiness zone is Portage, IN?
Based on frost date patterns, Portage falls approximately in 6a. USDA hardiness zones are determined by average annual minimum winter temperatures and guide both plant selection and planting timing for your location.
When should I start tomatoes indoors in Portage, IN?
Start tomato seeds indoors 6–8 weeks before your last frost date (around May 3). For Portage, that's roughly March 8 to March 22. Transplant outdoors 1–2 weeks after your last frost.
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