When to plant swiss chard in Portland

Swiss chard is cold-hardy, so every date keys off Portland's frost dates of Mar 1.
Step 1 · Sow
Start seeds indoors
Feb 1 – Feb 22
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Feb 15 – Mar 8
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Apr 6 – Apr 16
Picking runs until conditions turn against the crop.
Step 4 · Second sowing
Autumn / second sowing
Aug 12 – Aug 26
A second window for a fall crop, timed to mature before the first frost.
Step 5 · Second harvest
Autumn crop harvest
Oct 8 – Oct 18
Maturity window for the second sowing.
Window
Days to maturity
50 – 60 d
Portland's 266-day season leaves this much room.
Swiss chard on Portland'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 1
NOV 22

Common questions

When can I sow swiss chard outdoors in Portland?

Direct-sow around mid February (Feb 15–Mar 8) in Portland, based on its local frost dates. Confidence 88%.

When will swiss chard be ready to harvest in Portland?

Expect to harvest from around early April (Apr 6–Apr 16) in Portland, based on its local frost dates. Confidence 79%.

When should I start swiss chard seeds indoors in Portland?

Start seeds indoors around early February (Feb 1–Feb 22) in Portland, based on its local frost dates. Confidence 84%.

When can I transplant swiss chard outdoors in Portland?

Transplant outdoors around mid February (Feb 15–Mar 8) in Portland, based on its local frost dates. Confidence 88%.

Can I plant swiss chard in autumn in Portland?

Yes — Portland supports a second, autumn sowing of swiss chard around mid August (Aug 12–Aug 26), timed to mature before the first fall frost.

How long is the growing season in Portland?

Portland has roughly 266 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 Portland's frost dates.

Confidence 88/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.