When to plant pumpkin in Washington

In Washington, typical last spring frost is April 1 and typical first fall frost is November 11. Typical last spring frost: April 1. Pumpkin in Washington is a good fit outdoors. The suitable growing window of 132 days covers the 90–120 days this plant usually needs.

Pumpkin

How to grow Pumpkin Washington climate Weekly temperatures and windows

Where are you growing?

Comfortable

Comfortable in greenhouse

Comfortable in a cold frame

Pumpkin in Washington is a good fit outdoors. The suitable growing window of 132 days covers the 90–120 days this plant usually needs.

When to plantMay 11 – June 19

Harvest: August 9 – November 5
Season vs crop: 132 grow days vs 90–120 needed
Typical frost (last spring – first fall): April 1 – November 11

Pumpkin in Washington is a good fit outdoors. The suitable growing window of 132 days covers the 90–120 days this plant usually needs.

Planting conditions

Direct sow
Grow outdoors
Harvest

Local activity windows for this place and growing method. Blue fill is usually too cold for this plant. Dashed lines are typical last and first frost.

Suitable growing days in a row132

Days to harvest90–120 days from seed

May 11 – Jun 19

Direct sow

Jun 20 – Aug 8

Grow outdoors

Aug 9 – Nov 5

Harvest

Activity	Window	Notes
Direct sow	May 11 – Jun 19	Plant outdoors in this window.
Grow outdoors	Jun 20 – Aug 8	Plants grow outdoors until harvest.
Harvest	Aug 9 – Nov 5	Expected harvest from typical days to harvest.

Direct sow
Grow outdoors
Harvest

Blue fill is usually too cold for this plant. Dashed lines are typical last and first frost (35 seasons (1991–2025)). Adjust a week or two for your conditions.

Planting and growing across the year

Planting is the sow / plant-out window. Growing is daytime air versus this plant’s ideal (21 – 35 °C70 – 95 °F21 – 35 °C (70 – 95 °F)) and tolerable (16 – 38 °C61 – 100 °F16 – 38 °C (61 – 100 °F)) ranges.

Ideal / plantable
Tolerable
Too cold
Too hot
Outside window

Planting uses sow / plant-out rules; growing shows daytime air against this plant’s ideal and tolerable ranges.

Key dates

Typical last spring frostApril 1

Low-risk last spring frostApril 11

Typical first fall frostNovember 11

Low-risk first fall frostNovember 5

Frost-free days223

Outdoor sow dateMay 11

Direct sow windowMay 11 – June 19

Suitable growing windowMay 11 – September 19 (132 days)

Expected harvestAugust 9 – November 5

How these dates are judged

Ideal conditions: Daytime air from 21 – 35 °C70 – 95 °F21 – 35 °C (70 – 95 °F).
Suitable conditions: Daytime air from 16 – 38 °C61 – 100 °F16 – 38 °C (61 – 100 °F).
Last frost and first frost: Typical spring and fall frost dates for Washington, shown in the key dates.
Days to harvest: 90–120 days from seed, from typical days to harvest.
Sowing window: Dated sow and harvest bars use frost dates, soil minima, night limits, and last-sow count-back from typical crop timing. Air ratings on the weekly chart colour only weeks inside that same window — see weekly temperatures and windows.

Other plants for Washington

Calculated by Plan & Plant. Method. Data 35 seasons (1991–2025).

Frost and suitability dates are typical figures from climate statistics.

Based on 35 years (1991–2025) of ERA5-Land data from Open-Meteo, for an area of about 10 km. Typical dates, not a guarantee.

Dates for Washington use ERA5-Land cell 38.91, -77.04. How we calculated this · Algorithm 2026-10-season-10.

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