When to plant leeks in Colorado

Leeks
Plant out in Denver
Apr 20–May 4

Across Colorado the window opens between March 31 and April 26. Find your city below; the dates follow each town's own average last frost.

Start indoors, Denver
Feb 9–Feb 23
Plant out, Denver
Apr 20–May 4
Last frost, Denver
May 4

Start seeds indoors 10–12 weeks before the last frost; plant out up to 2 weeks before the last frost. Plant leeks deep in a trench and fill it in as they grow to get long white stems.

Leeks planting dates by city

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
JanFebMarAprMayJunJulAugSepOctNovDec
DenverApr 20–May 4
Colorado SpringsApr 19–May 3
AuroraApr 23–May 7
Fort CollinsApr 18–May 2
LakewoodApr 19–May 3
ThorntonApr 18–May 2
ArvadaApr 21–May 5
WestminsterApr 18–May 2
GreeleyApr 18–May 2
PuebloApr 16–Apr 30
CentennialApr 21–May 5
BoulderApr 22–May 6
LongmontApr 23–May 7
LovelandApr 26–May 10
BroomfieldApr 18–May 2
Commerce CityApr 19–May 3
Grand JunctionMar 31–Apr 14
LittletonApr 18–May 2
BrightonApr 19–May 3
WindsorApr 19–May 3
ErieApr 23–May 7
NorthglennApr 18–May 2
Security-WidefieldApr 19–May 3
EnglewoodApr 18–May 2
Pueblo WestApr 12–Apr 26
Wheat RidgeApr 21–May 5
LafayetteApr 18–May 2
FountainApr 19–May 3
EvansApr 18–May 2
JohnstownApr 26–May 10
All 34 cities
CityStart indoorsPlant outLast frost
DenverFeb 9 to Feb 23Apr 20 to May 4May 4
Colorado SpringsFeb 8 to Feb 22Apr 19 to May 3May 3
AuroraFeb 12 to Feb 26Apr 23 to May 7May 7
Fort CollinsFeb 7 to Feb 21Apr 18 to May 2May 2
LakewoodFeb 8 to Feb 22Apr 19 to May 3May 3
ThorntonFeb 7 to Feb 21Apr 18 to May 2May 2
ArvadaFeb 10 to Feb 24Apr 21 to May 5May 5
WestminsterFeb 7 to Feb 21Apr 18 to May 2May 2
GreeleyFeb 7 to Feb 21Apr 18 to May 2May 2
PuebloFeb 5 to Feb 19Apr 16 to Apr 30Apr 30
CentennialFeb 10 to Feb 24Apr 21 to May 5May 5
BoulderFeb 11 to Feb 25Apr 22 to May 6May 6
LongmontFeb 12 to Feb 26Apr 23 to May 7May 7
LovelandFeb 15 to Mar 1Apr 26 to May 10May 10
BroomfieldFeb 7 to Feb 21Apr 18 to May 2May 2
Commerce CityFeb 8 to Feb 22Apr 19 to May 3May 3
Grand JunctionJan 20 to Feb 3Mar 31 to Apr 14Apr 14
LittletonFeb 7 to Feb 21Apr 18 to May 2May 2
BrightonFeb 8 to Feb 22Apr 19 to May 3May 3
WindsorFeb 8 to Feb 22Apr 19 to May 3May 3
ErieFeb 12 to Feb 26Apr 23 to May 7May 7
NorthglennFeb 7 to Feb 21Apr 18 to May 2May 2
Security-WidefieldFeb 8 to Feb 22Apr 19 to May 3May 3
EnglewoodFeb 7 to Feb 21Apr 18 to May 2May 2
Pueblo WestFeb 1 to Feb 15Apr 12 to Apr 26Apr 26
Wheat RidgeFeb 10 to Feb 24Apr 21 to May 5May 5
LafayetteFeb 7 to Feb 21Apr 18 to May 2May 2
FountainFeb 8 to Feb 22Apr 19 to May 3May 3
EvansFeb 7 to Feb 21Apr 18 to May 2May 2
JohnstownFeb 15 to Mar 1Apr 26 to May 10May 10
Four Square MileFeb 12 to Feb 26Apr 23 to May 7May 7
MontroseFeb 3 to Feb 17Apr 14 to Apr 28Apr 28
LouisvilleFeb 11 to Feb 25Apr 22 to May 6May 6
FirestoneFeb 12 to Feb 26Apr 23 to May 7May 7

Questions

When should I plant leeks in Colorado?

In Denver, plant out from April 20 to May 4. Across Colorado the window opens between March 31 and April 26, depending on the local last frost.

How is this date worked out?

Start seeds indoors 10–12 weeks before the last frost; plant out up to 2 weeks before the last frost. Frost dates are NOAA 1991–2020 averages for the weather station nearest each city.

More for Colorado

Leeks in other states

Frost dates for every city in Colorado