When to plant in Ken Caryl, CO
Planting dates worked out from Ken Caryl's own frost records, not a generic zone chart.
Safe to plant out
May 21
1 year in 10 has a later frost
Average last frost
May 8
about a 50% chance of a later one
Average first fall frost
Oct 12
1 year in 10 by Oct 5
Frost-free days
161
median, 1991–2020
Station used: Marston Fltr Plt · 7.9 km away · station 1682 m, town 1756 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 | Mar 26 – Apr 9 | May 21 – Jun 4 | Jul 15 |
| Sweet pepper | Mar 12 – Mar 26 | May 21 – Jun 4 | Jul 20 |
| Lettuce (leaf) | Mar 6 – Mar 13 | Apr 10 – Apr 24 | May 20 |
| Peas | — | Mar 27 – Apr 24 | May 21 |
| Bush beans | — | May 14 – Jun 4 | Jul 3 |
| Carrot | — | Apr 17 – May 29 | Jun 16 |
| Beet | — | Apr 10 – May 22 | May 30 |
| Potato | — | Apr 17 – May 8 | Jun 26 |
| Kale | Feb 27 – Mar 13 | Apr 10 – Apr 24 | May 23 |
| Broccoli | Feb 27 – Mar 13 | Apr 10 – May 1 | Jun 9 |
| Cucumber | Apr 23 – Apr 30 | May 21 – Jun 4 | Jul 10 |
| Summer squash and zucchini | Apr 23 – Apr 30 | May 21 – Jun 4 | Jul 5 |
| Winter squash | Apr 23 – Apr 30 | May 21 – Jun 4 | Aug 9 |
| Sweet corn | — | May 14 – Jun 4 | Jul 13 |
| Onion (from sets) | — | Apr 10 – May 1 | Jul 9 |
| Garlic | — | Sep 28 – Oct 26 (fall) | following summer |
| Spinach | — | Mar 27 – Apr 24 | May 4 |
| Basil | Apr 9 – Apr 23 | May 21 – Jun 4 | Jul 17 |
Ken Caryl'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 |
|---|---|
| 1999 | May 10 |
| 2001 | May 21 |
| 2004 | May 2 |
| 2005 | Jun 13 |
| 2006 | May 11 |
| 2007 | May 7 |
| 2008 | May 4 |
| 2009 | Apr 28 |
| 2010 | May 14 |
| 2011 | May 6 |
| 2012 | Apr 8 |
| 2013 | May 4 |
| 2014 | May 14 |
| 2015 | May 12 |
| 2016 | May 3 |
| 2017 | May 20 |
| 2018 | Apr 29 |
| 2019 | May 22 |
| 2020 | Apr 18 |
| 2021 | May 12 |
| 2022 | May 22 |
| 2023 | Apr 24 |
| 2024 | May 8 |
| 2025 | Apr 21 |
| 2026 | May 7 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 2001 | 136 |
| 2004 | 176 |
| 2005 | 115 |
| 2006 | 159 |
| 2007 | 154 |
| 2008 | 161 |
| 2010 | 165 |
| 2011 | 164 |
| 2012 | 179 |
| 2013 | 153 |
| 2014 | 166 |
| 2015 | 168 |
| 2016 | 169 |
| 2017 | 141 |
| 2018 | 163 |
| 2019 | 140 |
| 2020 | 143 |
| 2021 | 153 |
| 2022 | 154 |
| 2023 | 172 |
| 2024 | 175 |
| 2025 | 180 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1999 | 16.9 °C |
| 2001 | 18.3 °C |
| 2004 | 16.6 °C |
| 2005 | 17.4 °C |
| 2006 | 17.9 °C |
| 2007 | 17.8 °C |
| 2008 | 16.6 °C |
| 2009 | 16.2 °C |
| 2010 | 17.1 °C |
| 2011 | 17.1 °C |
| 2012 | 19.1 °C |
| 2013 | 17.2 °C |
| 2014 | 17.2 °C |
| 2015 | 17.3 °C |
| 2016 | 17.6 °C |
| 2017 | 17.3 °C |
| 2018 | 18.1 °C |
| 2019 | 17.4 °C |
| 2020 | 18.2 °C |
| 2021 | 18.0 °C |
| 2022 | 18.2 °C |
| 2023 | 16.7 °C |
| 2024 | 18.2 °C |
| 2025 | 17.5 °C |
| 2026 | 18.7 °C |
What this means for you: This station's record is too short to show a reliable trend yet.
Source: daily records from Marston Fltr Plt (NOAA GHCN-Daily). Years with too many missing days are left out.