When to plant swiss chard in Washington

Swiss chard is cold-hardy, so every date keys off Washington's frost dates of Mar 24.
Step 1 · Sow
Start seeds indoors
Feb 24 – Mar 17
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Mar 12 – Apr 2
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
May 1 – May 11
Picking runs until conditions turn against the crop.
Step 4 · Second sowing
Autumn / second sowing
Aug 15 – Aug 29
A second window for a fall crop, timed to mature before the first frost.
Step 5 · Second harvest
Autumn crop harvest
Oct 11 – Oct 21
Maturity window for the second sowing.
Window
Days to maturity
50 – 60 d
Washington's 234-day season leaves this much room.
Swiss chard on Washington'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
MAR 24
NOV 17

Common questions

When can I sow swiss chard outdoors in Washington?

Direct-sow around mid March (Mar 12–Apr 2) in Washington, based on its local frost dates. Confidence 86%.

When will swiss chard be ready to harvest in Washington?

Expect to harvest from around early May (May 1–May 11) in Washington, based on its local frost dates. Confidence 80%.

When should I start swiss chard seeds indoors in Washington?

Start seeds indoors around late February (Feb 24–Mar 17) in Washington, based on its local frost dates. Confidence 85%.

When can I transplant swiss chard outdoors in Washington?

Transplant outdoors around mid March (Mar 12–Apr 2) in Washington, based on its local frost dates. Confidence 86%.

Can I plant swiss chard in autumn in Washington?

Yes — Washington supports a second, autumn sowing of swiss chard around mid August (Aug 15–Aug 29), timed to mature before the first fall frost.

How long is the growing season in Washington?

Washington has roughly 234 frost-free days, which is enough time to grow swiss chard to maturity outdoors.

The rule of thumb

Sow swiss chard 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 Washington's frost dates.

Confidence 89/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.