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USDA hardiness zone lookup

Portland (Mt. Scott) (97206) — USDA Zone 9a

Portland (Mt. Scott), Oregon · 234-day growing season

Frost dates and growing season for 97206

USDA hardiness zoneZone 9a
Average last spring frostMarch 25
Average first fall frostNovember 14
Growing season length~234 days
Temperature range (F)20 to 30°F
Temperature range (C)-7 to -1°C

These are 50%-probability averages modeled from this ZIP's USDA hardiness zone and regional climate normals — not a single-station reading. In a typical year the last spring frost will have passed by March 25, but in a colder-than-average year it can run 1-2 weeks later. Plant tender crops (tomatoes, peppers, basil) once both soil and night temperatures are consistently warm — a thermometer beats the calendar.

Growing season in Portland (Mt. Scott)

Portland (Mt. Scott), Oregon sits in USDA Zone 9a, with roughly 234 frost-free days between an average last spring frost around March 25 and a first fall frost around November 14. That is a long season — succession-sow through summer and run a full fall crop; heat-sensitive greens still need spring/autumn timing.

What grows in Portland (Mt. Scott)

Portland (Mt. Scott) falls in USDA Zone 9a, which means the same hardiness constraints apply as the full Zone 9 guide. Vegetables, herbs, and fruit trees rated to Zone 9a (or hardier) will overwinter here in a typical year.

What to plant in Portland (Mt. Scott) this week

Portland (Mt. Scott) is in the winter hold — outdoor planting is on pause. Use this time to plan, order seeds, and prep beds. Tomato and pepper seeds can start indoors 6-10 weeks before your last frost (March 25).

Full planting calendar for Portland (Mt. Scott)

Crop-by-crop sowing, transplant, and harvest dates calibrated to zone 9 averages:

Local microclimate notes

Zone tables give you the average — but Portland (Mt. Scott)gardens vary. South-facing walls and paved areas can run a full half-zone warmer than the published rating. Low-lying spots, frost pockets, and shaded north sides can run colder. If you've gardened here a few seasons, your own frost record (the last time you actually got frost damage) is more accurate than any national average.

Source and methodology

Hardiness zone from the USDA Plant Hardiness Zone Map (2023 revision). Frost-date and growing-season figures are modeled from this ZIP's USDA hardiness zone and regional NOAA 1991-2020 climate normals — they are zone-level estimates, not a per-station record, so treat them as planning guidance and confirm against your own local frost history. Crop recommendations are drawn from US Cooperative Extension references and curated by the Growli editorial team. Last reviewed May 2026.

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