When to plant zucchini in Colorado

Zucchini
Sow outdoors in Denver
May 11–May 25

Across Colorado the window opens between April 21 and May 17. Find your city below; the dates follow each town's own average last frost.

Sow outdoors, Denver
May 11–May 25
Last sowing for a harvest
Jul 26
Last frost, Denver
May 4

Sow outdoors 1–3 weeks after the last frost. Two plants are plenty for most families. Pick fruit at 6–8 inches.

Zucchini planting dates by city

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
JanFebMarAprMayJunJulAugSepOctNovDec
DenverMay 11–May 25
Colorado SpringsMay 10–May 24
AuroraMay 14–May 28
Fort CollinsMay 9–May 23
LakewoodMay 10–May 24
ThorntonMay 9–May 23
ArvadaMay 12–May 26
WestminsterMay 9–May 23
GreeleyMay 9–May 23
PuebloMay 7–May 21
CentennialMay 12–May 26
BoulderMay 13–May 27
LongmontMay 14–May 28
LovelandMay 17–May 31
BroomfieldMay 9–May 23
Commerce CityMay 10–May 24
Grand JunctionApr 21–May 5
LittletonMay 9–May 23
BrightonMay 10–May 24
WindsorMay 10–May 24
ErieMay 14–May 28
NorthglennMay 9–May 23
Security-WidefieldMay 10–May 24
EnglewoodMay 9–May 23
Pueblo WestMay 3–May 17
Wheat RidgeMay 12–May 26
LafayetteMay 9–May 23
FountainMay 10–May 24
EvansMay 9–May 23
JohnstownMay 17–May 31
All 34 cities
CitySow outdoorsLast frost
DenverMay 11 to May 25May 4
Colorado SpringsMay 10 to May 24May 3
AuroraMay 14 to May 28May 7
Fort CollinsMay 9 to May 23May 2
LakewoodMay 10 to May 24May 3
ThorntonMay 9 to May 23May 2
ArvadaMay 12 to May 26May 5
WestminsterMay 9 to May 23May 2
GreeleyMay 9 to May 23May 2
PuebloMay 7 to May 21Apr 30
CentennialMay 12 to May 26May 5
BoulderMay 13 to May 27May 6
LongmontMay 14 to May 28May 7
LovelandMay 17 to May 31May 10
BroomfieldMay 9 to May 23May 2
Commerce CityMay 10 to May 24May 3
Grand JunctionApr 21 to May 5Apr 14
LittletonMay 9 to May 23May 2
BrightonMay 10 to May 24May 3
WindsorMay 10 to May 24May 3
ErieMay 14 to May 28May 7
NorthglennMay 9 to May 23May 2
Security-WidefieldMay 10 to May 24May 3
EnglewoodMay 9 to May 23May 2
Pueblo WestMay 3 to May 17Apr 26
Wheat RidgeMay 12 to May 26May 5
LafayetteMay 9 to May 23May 2
FountainMay 10 to May 24May 3
EvansMay 9 to May 23May 2
JohnstownMay 17 to May 31May 10
Four Square MileMay 14 to May 28May 7
MontroseMay 5 to May 19Apr 28
LouisvilleMay 13 to May 27May 6
FirestoneMay 14 to May 28May 7

Questions

When should I plant zucchini in Colorado?

In Denver, sow outdoors from May 11 to May 25. Across Colorado the window opens between April 21 and May 17, depending on the local last frost.

How is this date worked out?

Sow outdoors 1–3 weeks after the last frost. Frost dates are NOAA 1991–2020 averages for the weather station nearest each city.

More for Colorado

Zucchini in other states

Frost dates for every city in Colorado