When to plant cabbage in Denver
Cabbage is cold-hardy, so every date keys off Denver's frost dates of May 4.
Step 1 · Sow
Start seeds indoors
Mar 23 – Apr 13
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 13 – May 4
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jun 22 – Jul 22
Picking runs until conditions turn against the crop.
Step 4 · Second sowing
Autumn / second sowing
Jun 11 – Jun 25
A second window for a fall crop, timed to mature before the first frost.
Step 5 · Second harvest
Autumn crop harvest
Aug 27 – Sep 26
Maturity window for the second sowing.
Window
Days to maturity
70 – 100 d
Denver's 157-day season leaves this much room.
Cabbage on Denver's growing year
Frost-bounded season with crops mapped onto the 12-month axis.
Frost risk Growing Harvest
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
FROST
FROST
MAY 4
OCT 10
Common questions
When will cabbage be ready to harvest in Denver?
Expect to harvest from around late June (Jun 22–Jul 22) in Denver, based on its local frost dates. Confidence 76%.
When should I start cabbage seeds indoors in Denver?
Start seeds indoors around late March (Mar 23–Apr 13) in Denver, based on its local frost dates. Confidence 81%.
When can I transplant cabbage outdoors in Denver?
Transplant outdoors around mid April (Apr 13–May 4) in Denver, based on its local frost dates. Confidence 85%.
Can I plant cabbage in autumn in Denver?
Yes — Denver supports a second, autumn sowing of cabbage around mid June (Jun 11–Jun 25), timed to mature before the first fall frost.
How long is the growing season in Denver?
Denver has roughly 157 frost-free days, which is enough time to grow cabbage to maturity outdoors.
The rule of thumb
Sow cabbage as soon as the soil is workable — it tolerates cool weather and light frost. Every date on this page is derived from that rule and Denver's frost dates.
Confidence 85/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.