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When to plant in Merton, WI

Planting dates worked out from Merton'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 2
about a 50% chance of a later one
Average first fall frost
Oct 10
1 year in 10 by Sep 30
Frost-free days
160
median, 1991–2020

Station used: Oconomowoc Wwtp · 16.8 km away · station 262 m, town 297 m. How we match towns to stations

This season

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Planting dates for common crops

CropStart indoorsPlant out or sowHarvest 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 3 – Mar 10 Apr 7 – Apr 21 May 17
Peas — Apr 7 – May 5 Jun 1
Bush beans — May 14 – Jun 4 Jul 3
Carrot — Apr 17 – May 29 Jun 16
Beet — Apr 17 – May 29 Jun 6
Potato — Apr 17 – May 8 Jun 26
Kale Mar 3 – Mar 17 Apr 14 – Apr 28 May 27
Broccoli Feb 24 – Mar 10 Apr 7 – Apr 28 Jun 6
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 7 – Apr 28 Jul 6
Garlic — Sep 26 – Oct 24 (fall) following summer
Spinach — Apr 7 – May 5 May 15
Basil Apr 9 – Apr 23 May 21 – Jun 4 Jul 17

Plan all 65 crops for Merton

Merton's weather over time

How the growing season has shifted here, year by year, from the station's own records.

Apr 15May 1May 15Jun 1 1900191019201930194019501960197019801990200020102020
Each year's last spring frostLong-term trend
See the data as a table
YearLast spring frost
1893May 7
1894May 4
1895May 27
1896Apr 22
1945Jun 4
1946Apr 27
1947May 10
1948May 8
1949Apr 25
1950May 8
1951Apr 26
1952Apr 16
1953Apr 28
1954May 9
1955Apr 7
1956Apr 30
1957May 5
1958May 7
1959Apr 22
1960May 12
1961May 27
1962Apr 20
1963May 23
1964Apr 15
1965Apr 28
1966May 13
1967May 6
1968May 6
1969Apr 30
1970May 6
1972Apr 27
1973May 17
1974May 10
1975Apr 21
1976May 8
1977May 10
1978May 11
1979May 1
1980Apr 26
1981May 12
1982Apr 27
1983May 16
1984May 1
1985Apr 9
1986May 2
1987Apr 8
1988Apr 28
1989May 7
1990May 10
1991Apr 21
1992May 26
1993Apr 27
1994May 27
1995Apr 25
1996May 13
1997May 21
1998Apr 28
1999Apr 25
2000Apr 22
2001Apr 19
2002May 21
2003Apr 23
2004May 3
2005May 4
2006May 12
2007Apr 16
2008May 4
2009Apr 22
2010May 9
2011Apr 30
2012Apr 27
2013May 13
2014Apr 23
2015Apr 28
2017May 3
2018Apr 30
2019Apr 28
2021May 12
2022Apr 28
2023Apr 26
2024Apr 25
2025Apr 16

What this means for you: Since 1893, Merton's last spring frost has stayed at about the same time of year. The frost-free season has grown by about 2 days per decade. Year-to-year swings are large, so keep using the safe date rather than the trend.

Source: daily records from Oconomowoc Wwtp (NOAA GHCN-Daily). Years with too many missing days are left out.

Nearby towns

HartlandSussexPewaukeeNashotahOkauchee LakeLannon