When to plant in Ankeny, IA
Planting dates worked out from Ankeny's own frost records, not a generic zone chart.
Safe to plant out
May 10
1 year in 10 has a later frost
Average last frost
Apr 26
about a 50% chance of a later one
Average first fall frost
Oct 11
1 year in 10 by Sep 29
Frost-free days
170
median, 1991–2020
Station used: Ankeny · 3.7 km away · station 297 m, town 302 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 15 – Mar 29 | May 10 – May 24 | Jul 4 |
| Sweet pepper | Mar 1 – Mar 15 | May 10 – May 24 | Jul 9 |
| Lettuce (leaf) | Feb 22 – Mar 1 | Mar 29 – Apr 12 | May 8 |
| Peas | — | Mar 29 – Apr 26 | May 23 |
| Bush beans | — | May 3 – May 24 | Jun 22 |
| Carrot | — | Apr 8 – May 20 | Jun 7 |
| Beet | — | Apr 8 – May 20 | May 28 |
| Potato | — | Apr 8 – Apr 29 | Jun 17 |
| Kale | Feb 22 – Mar 8 | Apr 5 – Apr 19 | May 18 |
| Broccoli | Feb 15 – Mar 1 | Mar 29 – Apr 19 | May 28 |
| Cucumber | Apr 12 – Apr 19 | May 10 – May 24 | Jun 29 |
| Summer squash and zucchini | Apr 12 – Apr 19 | May 10 – May 24 | Jun 24 |
| Winter squash | Apr 12 – Apr 19 | May 10 – May 24 | Jul 29 |
| Sweet corn | — | May 3 – May 24 | Jul 2 |
| Onion (from sets) | — | Mar 29 – Apr 19 | Jun 27 |
| Garlic | — | Sep 27 – Oct 25 (fall) | following summer |
| Spinach | — | Mar 29 – Apr 26 | May 6 |
| Basil | Mar 29 – Apr 12 | May 10 – May 24 | Jul 6 |
Ankeny'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 |
|---|---|
| 1951 | Apr 23 |
| 1952 | Apr 16 |
| 1953 | May 13 |
| 1954 | May 8 |
| 1955 | Apr 7 |
| 1956 | May 16 |
| 1957 | Apr 14 |
| 1958 | Apr 29 |
| 1959 | Apr 22 |
| 1960 | Apr 30 |
| 1961 | May 2 |
| 1962 | Apr 19 |
| 1963 | May 22 |
| 1964 | Apr 9 |
| 1965 | Apr 19 |
| 1966 | May 10 |
| 1967 | May 4 |
| 1968 | Apr 25 |
| 1969 | Apr 29 |
| 1970 | May 2 |
| 1971 | May 3 |
| 1972 | Apr 25 |
| 1974 | Apr 25 |
| 1975 | Apr 20 |
| 1976 | May 3 |
| 1977 | Apr 7 |
| 1978 | May 2 |
| 1980 | May 8 |
| 1981 | Apr 15 |
| 1982 | Apr 22 |
| 1983 | Apr 20 |
| 1984 | Apr 22 |
| 1985 | Apr 9 |
| 1986 | Apr 22 |
| 1987 | Apr 5 |
| 1988 | Apr 24 |
| 1989 | May 7 |
| 1990 | Apr 30 |
| 1991 | Apr 24 |
| 1992 | May 6 |
| 1993 | Apr 21 |
| 1994 | May 1 |
| 1995 | Apr 26 |
| 1996 | Apr 28 |
| 1997 | May 16 |
| 1998 | Apr 17 |
| 1999 | Apr 21 |
| 2000 | Apr 13 |
| 2002 | Apr 10 |
| 2003 | Apr 11 |
| 2004 | May 4 |
| 2005 | May 5 |
| 2006 | May 12 |
| 2007 | Apr 14 |
| 2008 | Apr 30 |
| 2009 | Apr 16 |
| 2010 | May 9 |
| 2011 | May 4 |
| 2013 | May 4 |
| 2015 | Apr 27 |
| 2016 | Apr 12 |
| 2017 | Apr 7 |
| 2020 | May 10 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1952 | 172 |
| 1953 | 146 |
| 1954 | 162 |
| 1955 | 190 |
| 1956 | 136 |
| 1957 | 178 |
| 1958 | 154 |
| 1959 | 169 |
| 1960 | 171 |
| 1961 | 148 |
| 1962 | 187 |
| 1963 | 159 |
| 1964 | 178 |
| 1965 | 175 |
| 1966 | 159 |
| 1967 | 146 |
| 1968 | 161 |
| 1969 | 167 |
| 1970 | 160 |
| 1971 | 180 |
| 1972 | 157 |
| 1974 | 149 |
| 1975 | 164 |
| 1976 | 155 |
| 1977 | 187 |
| 1978 | 166 |
| 1980 | 149 |
| 1981 | 169 |
| 1982 | 180 |
| 1983 | 155 |
| 1984 | 156 |
| 1985 | 174 |
| 1986 | 174 |
| 1987 | 180 |
| 1988 | 163 |
| 1990 | 163 |
| 1991 | 148 |
| 1992 | 145 |
| 1993 | 170 |
| 1994 | 161 |
| 1995 | 148 |
| 1996 | 157 |
| 2000 | 175 |
| 2002 | 179 |
| 2003 | 170 |
| 2004 | 150 |
| 2005 | 155 |
| 2006 | 152 |
| 2007 | 191 |
| 2008 | 180 |
| 2009 | 176 |
| 2010 | 172 |
| 2011 | 150 |
| 2013 | 171 |
| 2015 | 180 |
| 2016 | 183 |
| 2017 | 202 |
| 2020 | 160 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1951 | 17.3 °C |
| 1952 | 19.0 °C |
| 1953 | 18.6 °C |
| 1954 | 18.9 °C |
| 1955 | 20.0 °C |
| 1956 | 18.6 °C |
| 1957 | 18.3 °C |
| 1958 | 17.8 °C |
| 1959 | 18.7 °C |
| 1960 | 18.3 °C |
| 1961 | 17.1 °C |
| 1962 | 18.8 °C |
| 1963 | 19.8 °C |
| 1964 | 19.4 °C |
| 1965 | 18.8 °C |
| 1966 | 18.1 °C |
| 1967 | 17.7 °C |
| 1968 | 17.8 °C |
| 1969 | 17.9 °C |
| 1970 | 18.7 °C |
| 1971 | 18.5 °C |
| 1972 | 18.1 °C |
| 1974 | 17.7 °C |
| 1975 | 18.0 °C |
| 1976 | 18.7 °C |
| 1977 | 20.2 °C |
| 1978 | 19.2 °C |
| 1980 | 19.6 °C |
| 1981 | 19.4 °C |
| 1982 | 17.9 °C |
| 1983 | 19.1 °C |
| 1984 | 18.4 °C |
| 1985 | 19.4 °C |
| 1986 | 19.6 °C |
| 1987 | 20.0 °C |
| 1988 | 20.6 °C |
| 1990 | 17.7 °C |
| 1991 | 19.0 °C |
| 1992 | 16.3 °C |
| 1994 | 17.9 °C |
| 1995 | 17.6 °C |
| 1996 | 16.9 °C |
| 1998 | 19.2 °C |
| 1999 | 18.0 °C |
| 2000 | 18.9 °C |
| 2002 | 18.3 °C |
| 2003 | 18.6 °C |
| 2004 | 18.2 °C |
| 2005 | 19.8 °C |
| 2006 | 19.1 °C |
| 2007 | 19.6 °C |
| 2008 | 18.1 °C |
| 2009 | 17.9 °C |
| 2010 | 20.1 °C |
| 2011 | 19.1 °C |
| 2013 | 18.1 °C |
| 2015 | 18.6 °C |
| 2016 | 19.3 °C |
| 2017 | 19.5 °C |
| 2020 | 18.9 °C |
What this means for you: Since 1951, Ankeny's last spring frost has stayed at about the same time of year. The frost-free season has grown by about 1 days per decade. Year-to-year swings are large, so keep using the safe date rather than the trend.
Source: daily records from Ankeny (NOAA GHCN-Daily). Years with too many missing days are left out.