When to plant garlic in Boise
Garlic is cold-hardy, so every date keys off Boise's frost dates of May 2.
Step 1 · Sow
Direct sow outdoors
Sep 19 – Oct 10
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
May 17 – May 17
Picking runs until conditions turn against the crop.
Window
Days to maturity
240 d
Boise's 168-day season leaves this much room.
Garlic on Boise'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 2
OCT 17
Common questions
When can I sow garlic outdoors in Boise?
Direct-sow around mid September (Sep 19–Oct 10) in Boise, based on its local frost dates. Confidence 89%.
When will garlic be ready to harvest in Boise?
Expect to harvest from around mid May (May 17–May 17) in Boise, based on its local frost dates. Confidence 80%.
How long is the growing season in Boise?
Boise has roughly 168 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 Boise's frost dates.
Confidence 89/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.