Frost dates for Owatonna, MN
When the last spring frost and first fall frost usually come, and when to plant, from 30 years of NOAA weather records.
Last spring frost
May 5
typical year
Safe to plant
May 20
frost is over in 9 of 10 years
First fall frost
October 6
typical year
Growing season
154 days
frost-free, typical year
Frost watch this week
Tonight's and the next six nights' lows from the National Weather Service forecast for the station's location. Frost: 32°F or colder. Possible frost: 33–36°F, mostly in low spots on clear, still nights.
When to plant
Counted from this page's frost dates. Warm-season crops wait for the safe-to-plant date.
| Crop | Start indoors | Plant outside | Fall planting |
|---|---|---|---|
| Cool-season crops | |||
| Peas | – | Apr 7 – 21 | – |
| Spinach | – | Mar 24 – Apr 14 | Aug 11 – 25 |
| Lettuce | – | Apr 7 – 28 | Aug 11 – 25 |
| Radishes | – | Apr 7 – May 19 | Aug 25 – Sep 8 |
| Onions | – | Apr 7 – 21 | – |
| Potatoes | – | Apr 14 – 28 | – |
| Carrots | – | Apr 14 – May 5 | Jul 14 – 28 |
| Beets | – | Apr 7 – 21 | Jul 28 – Aug 11 |
| Kale | Feb 24 – Mar 10 | Apr 7 – 21 | Jul 28 – Aug 11 |
| Broccoli | Feb 24 – Mar 10 | Apr 21 – May 5 | Jul 28 – Aug 11 |
| Cabbage | Feb 10 – 24 | Apr 7 – 21 | Jul 28 – Aug 11 |
| Garlic | – | – | Aug 25 – Sep 15 |
| Warm-season crops | |||
| Tomatoes | Mar 25 – Apr 8 | May 20 – Jun 3 | – |
| Peppers | Mar 18 – Apr 1 | May 27 – Jun 10 | – |
| Cucumbers | – | May 20 – Jun 10 | – |
| Zucchini | – | May 20 – Jun 17 | – |
| Pumpkins | – | May 20 – Jun 10 | – |
| Green beans | – | May 20 – Jul 28 | – |
| Sweet corn | – | May 20 – Jun 17 | – |
| Basil | Apr 15 – 29 | May 27 – Jun 3 | – |
Onions: from sets. Green beans: until 10 weeks before the first fall frost. Garlic: harvest next summer.
The year at a glance
Start indoors Plant outside Fall planting
The chance of frost, by date
| 1 year in 10 | Half of years | 9 years in 10 | |
|---|---|---|---|
| Spring frost after | May 20 | May 5 | April 20 |
| Fall frost before | September 23 | October 6 | October 21 |
Frost here means 32°F or colder. Read across: in 1 year in 10, spring frost carries on past the first date, which is why that date is the safe-to-plant date.
Hard freeze (28°F)
A hard freeze kills most garden plants, even hardy ones. The last one in spring usually comes around April 25 (May 12 in a late year), and the first one in fall around October 18.
Towns that use these dates
This is the nearest NOAA station with frost records for 4 towns.
Owatonna, Medford, Ellendale, Claremont
Where these dates come from
NOAA weather station OWATONNA, MN US (USC00216287), 1991–2020 climate normals. It's the nearest station for 6 zip codes, all within 17 miles:
55049, 55060, 55917, 55924, 56026, 56046
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.