When to plant lettuce in Riverside

Lettuce is cold-hardy, so every date keys off Riverside's frost dates of Feb 16.
Step 1 · Sow
Start seeds indoors
Jan 19 – Feb 9
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Jan 26 – Feb 16
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Mar 12 – Mar 27
Picking runs until conditions turn against the crop.
Step 4 · Second sowing
Autumn / second sowing
Sep 2 – Sep 16
A second window for a fall crop, timed to mature before the first frost.
Step 5 · Second harvest
Autumn crop harvest
Oct 24 – Nov 8
Maturity window for the second sowing.
Window
Days to maturity
45 – 60 d
Riverside's 293-day season leaves this much room.
Lettuce on Riverside'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
FEB 16
DEC 6

Common questions

When can I sow lettuce outdoors in Riverside?

Direct-sow around mid January (Jan 19–Feb 9) in Riverside, based on its local frost dates. Confidence 78%.

When will lettuce be ready to harvest in Riverside?

Expect to harvest from around mid March (Mar 12–Mar 27) in Riverside, based on its local frost dates. Confidence 70%.

When should I start lettuce seeds indoors in Riverside?

Start seeds indoors around mid January (Jan 19–Feb 9) in Riverside, based on its local frost dates. Confidence 74%.

When can I transplant lettuce outdoors in Riverside?

Transplant outdoors around late January (Jan 26–Feb 16) in Riverside, based on its local frost dates. Confidence 78%.

Can I plant lettuce in autumn in Riverside?

Yes — Riverside supports a second, autumn sowing of lettuce around early September (Sep 2–Sep 16), timed to mature before the first fall frost.

How long is the growing season in Riverside?

Riverside has roughly 293 frost-free days, which is enough time to grow lettuce to maturity outdoors.

The rule of thumb

Sow lettuce 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 Riverside's frost dates.

Confidence 78/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.