Frost dates for Castlewood, SD
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 6
typical year
Safe to plant
May 20
frost is over in 9 of 10 years
First fall frost
October 1
typical year
Growing season
145 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 8 – 22 | – |
| Spinach | – | Mar 25 – Apr 15 | Aug 6 – 20 |
| Lettuce | – | Apr 8 – 29 | Aug 6 – 20 |
| Radishes | – | Apr 8 – May 20 | Aug 20 – Sep 3 |
| Onions | – | Apr 8 – 22 | – |
| Potatoes | – | Apr 15 – 29 | – |
| Carrots | – | Apr 15 – May 6 | Jul 9 – 23 |
| Beets | – | Apr 8 – 22 | Jul 23 – Aug 6 |
| Kale | Feb 25 – Mar 11 | Apr 8 – 22 | Jul 23 – Aug 6 |
| Broccoli | Feb 25 – Mar 11 | Apr 22 – May 6 | Jul 23 – Aug 6 |
| Cabbage | Feb 11 – 25 | Apr 8 – 22 | Jul 23 – Aug 6 |
| Garlic | – | – | Aug 20 – Sep 10 |
| 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 23 | – |
| 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 6 | April 25 |
| Fall frost before | September 19 | October 1 | October 14 |
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 29 (May 11 in a late year), and the first one in fall around October 11.
Towns that use these dates
This is the nearest NOAA station with frost records for 3 towns.
Castlewood, Lake Norden, Hayti
Where these dates come from
NOAA weather station CASTLEWOOD #2, SD US (USC00391520), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 13 miles:
57241, 57248
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.