When to plant in Plentywood, MT
Planting dates worked out from Plentywood's own frost records, not a generic zone chart.
Safe to plant out
Jun 3
1 year in 10 has a later frost
Average last frost
May 21
about a 50% chance of a later one
Average first fall frost
Sep 15
1 year in 10 by Sep 8
Frost-free days
119
median, 1991–2020
Station used: Plentywood · 0.3 km away · station 624 m, town 624 m. How we match towns to stations
This season
Plan your garden.
Planting dates for common crops
| Crop | Start indoors | Plant out or sow | Harvest from |
|---|---|---|---|
| Tomato | Apr 8 – Apr 22 | Jun 3 – Jun 17 | Jul 28 |
| Sweet pepper | Mar 25 – Apr 8 | Jun 3 – Jun 17 | Aug 2 |
| Lettuce (leaf) | Mar 19 – Mar 26 | Apr 23 – May 7 | Jun 2 |
| Peas | — | Apr 19 – May 17 | Jun 13 |
| Bush beans | — | May 27 – Jun 17 | Jul 16 |
| Carrot | — | Apr 30 – Jun 11 | Jun 29 |
| Beet | — | Apr 28 – Jun 9 | Jun 17 |
| Potato | — | Apr 30 – May 21 | Jul 9 |
| Kale | Mar 15 – Mar 29 | Apr 26 – May 10 | Jun 8 |
| Broccoli | Mar 12 – Mar 26 | Apr 23 – May 14 | Jun 22 |
| Cucumber | May 6 – May 13 | Jun 3 – Jun 17 | Jul 23 |
| Summer squash and zucchini | May 6 – May 13 | Jun 3 – Jun 17 | Jul 18 |
| Winter squash | May 6 – May 13 | Jun 3 – Jun 17 | Aug 22 |
| Sweet corn | — | May 27 – Jun 17 | Jul 26 |
| Onion (from sets) | — | Apr 23 – May 14 | Jul 22 |
| Garlic | — | Sep 1 – Sep 29 (fall) | following summer |
| Spinach | — | Apr 19 – May 17 | May 27 |
| Basil | Apr 22 – May 6 | Jun 3 – Jun 17 | Jul 30 |
Plentywood's weather over time
How the growing season has shifted here, year by year, from the station's own records.
Each year's last spring frostLong-term trend
See the data as a table
| Year | Last spring frost |
|---|---|
| 1986 | May 17 |
| 1987 | May 20 |
| 1988 | May 4 |
| 1989 | May 6 |
| 1990 | May 17 |
| 1991 | May 6 |
| 1992 | May 25 |
| 1993 | May 19 |
| 1994 | May 9 |
| 1995 | May 25 |
| 1996 | May 13 |
| 1997 | May 20 |
| 1998 | Jun 4 |
| 1999 | May 17 |
| 2000 | Jun 18 |
| 2001 | Jun 2 |
| 2002 | May 26 |
| 2003 | May 22 |
| 2004 | Jun 24 |
| 2005 | May 15 |
| 2012 | May 12 |
| 2013 | May 12 |
| 2014 | May 17 |
| 2015 | May 21 |
| 2016 | May 16 |
| 2017 | May 20 |
| 2018 | Apr 27 |
| 2019 | May 28 |
| 2020 | May 13 |
| 2021 | May 14 |
| 2022 | Jun 4 |
| 2023 | May 20 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1986 | 111 |
| 1987 | 111 |
| 1988 | 137 |
| 1989 | 126 |
| 1990 | 134 |
| 1991 | 134 |
| 1992 | 107 |
| 1993 | 117 |
| 1994 | 135 |
| 1995 | 116 |
| 1996 | 120 |
| 1997 | 119 |
| 1999 | 114 |
| 2000 | 63 |
| 2001 | 98 |
| 2002 | 115 |
| 2003 | 115 |
| 2012 | 127 |
| 2013 | 130 |
| 2014 | 116 |
| 2015 | 130 |
| 2016 | 119 |
| 2017 | 125 |
| 2018 | 130 |
| 2019 | 125 |
| 2020 | 117 |
| 2021 | 130 |
| 2022 | 124 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 2009 | 14.9 °C |
| 2012 | 16.0 °C |
| 2013 | 14.6 °C |
| 2014 | 13.7 °C |
| 2015 | 14.6 °C |
| 2016 | 14.7 °C |
| 2017 | 14.7 °C |
| 2018 | 13.8 °C |
| 2019 | 13.5 °C |
| 2020 | 13.6 °C |
| 2021 | 14.9 °C |
| 2022 | 14.1 °C |
What this means for you: Since 1986, Plentywood's last spring frost has stayed at about the same time of year. Year-to-year swings are large, so keep using the safe date rather than the trend.
Source: daily records from Plentywood (NOAA GHCN-Daily). Years with too many missing days are left out.