GrowZone

ZIP 97204 planting calendar

When to plant cucumbers in Portland, OR - Zone 9a

In ZIP 97204, plant cucumbers around Apr 11; this uses the Portland frost station, USDA zone 9a, and cucumbers timing rules.

Your Portland calendar has a 223-day estimated frost-free season. This estimate uses the representative Portland frost station, USDA zone 9a, and cucumbers timing rules.

Source: portland-intl frost station, USDA zone 9a, last updated 2026-06-28. Verify locally before planting high-value crops because microclimates, current weather, and yard exposure can move the safe date.

USDA zone 9a Portland frost station Oregon State University Extension Updated 2026-06-28
Read the method

Answer first

When to start cucumbers seeds indoors in Portland

In ZIP 97204, start cucumbers seeds indoors around Mar 11, about 21 days before the Apr 1 last-frost estimate.

Start cucumbers seeds indoors in Portland around Mar 11, about 21 days before the Apr 1 last-frost estimate.

Seed starting schedule

Cucumbers dates for Portland, OR

StepDateHow to use it
Start IndoorsMarch 11, 2026Start seeds under lights or in a bright indoor seed-starting space.
Transplant OutdoorsApril 11, 2026Move hardened-off seedlings outside after the frost-risk window.
Direct SowApril 11, 2026Sow seed outside when the crop and soil can handle the window.

Last frost

When is the last frost in Portland?

Portland (ZIP 97204) has an average last spring frost around Apr 1.

First frost

When is the first frost in Portland?

The average first fall frost is around Nov 10, giving about 223 frost-free days.

Season map

Cucumbers windows by month

JanFebMarAprMayJunJulAugSepOctNovDec
Start indoors
Mar 11
Direct sow
Apr 11
Transplant
Apr 11
Harvest
Jun 10
Frost watch
Sep 11

Reminder workflow

Every date has a next action

Start cucumbers indoorsMar 11
Last frost windowApr 1
Direct sow cucumbersApr 11
Transplant cucumbersApr 11
First cucumbers harvest windowJun 10
Last cucumbers sowing targetSep 11
SignalValueWhy it matters
Last frost estimateApril 1, 2026Warm-season transplant risk starts falling after this window.
First frost estimateNovember 10, 2026Fall planting counts backward from this date.
Season length223 daysLonger seasons can support succession crops.
Spacing12-18 inAirflow and root space affect yield.
Soil temperature65 F+Seeds and transplants stall in cold soil.

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Local data

Why this date changes by ZIP

Portland frost history and USDA zone 9a shift the safe planting window. GrowZone uses a local representative station instead of one national rule.

Oregon State University Extension is the kind of local source to verify against when a crop is expensive, weather is unusual, or your yard has a cold pocket.

Crop note

Cucumbers timing notes

Use a trellis if space is tight and keep soil evenly moist. Cucumbers prefers full sun, 12-18 in spacing, and soil near 65 F+.

For fall, count backward from Nov 10. A conservative last sowing target is around Sep 11.