When to plant garlic in Denver
Garlic is cold-hardy, so every date keys off Denver's frost dates of May 4.
Step 1 · Sow
Direct sow outdoors
Sep 12 – Oct 3
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
May 10 – May 10
Picking runs until conditions turn against the crop.
Window
Days to maturity
240 d
Denver's 157-day season leaves this much room.
Garlic 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 can I sow garlic outdoors in Denver?
Direct-sow around mid September (Sep 12–Oct 3) in Denver, based on its local frost dates. Confidence 85%.
When will garlic be ready to harvest in Denver?
Expect to harvest from around early May (May 10–May 10) in Denver, based on its local frost dates. Confidence 76%.
How long is the growing season in Denver?
Denver has roughly 157 frost-free days, which is marginal time to grow garlic to maturity outdoors.
The rule of thumb
Sow garlic 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.