When to plant swiss chard in Portland

Swiss chard is cold-hardy, so every date keys off Portland's frost dates of May 1.
Step 1 · Sow
Start seeds indoors
Apr 3 – Apr 24
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 23 – May 14
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jun 12 – Jun 22
Picking runs until conditions turn against the crop.
Step 4 · Second sowing
Autumn / second sowing
Jul 12 – Jul 26
A second window for a fall crop, timed to mature before the first frost.
Step 5 · Second harvest
Autumn crop harvest
Sep 7 – Sep 17
Maturity window for the second sowing.
Window
Days to maturity
50 – 60 d
Portland's 165-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
MAY 1
OCT 10

Common questions

When can I sow swiss chard outdoors in Portland?

Direct-sow around late April (Apr 23–May 14) in Portland, based on its local frost dates. Confidence 86%.

When will swiss chard be ready to harvest in Portland?

Expect to harvest from around mid June (Jun 12–Jun 22) in Portland, based on its local frost dates. Confidence 80%.

When should I start swiss chard seeds indoors in Portland?

Start seeds indoors around early April (Apr 3–Apr 24) in Portland, based on its local frost dates. Confidence 85%.

When can I transplant swiss chard outdoors in Portland?

Transplant outdoors around late April (Apr 23–May 14) in Portland, based on its local frost dates. Confidence 86%.

Can I plant swiss chard in autumn in Portland?

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

How long is the growing season in Portland?

Portland has roughly 165 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 89/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.