When to plant pumpkin in Detroit

In Detroit, typical last spring frost is April 12 and typical first fall frost is November 8. Typical last spring frost: April 12. Pumpkin in Detroit is doable with planning outdoors. 114 suitable days are enough for fast varieties (90 days) but not slow ones (120 days).

Pumpkin

How to grow Pumpkin Detroit climate Weekly temperatures and windows

Where are you growing?

Tight fit

Tight fit in greenhouse

Comfortable in a cold frame

Pumpkin in Detroit is doable with planning outdoors. 114 suitable days are enough for fast varieties (90 days) but not slow ones (120 days).

When to plantMay 21 – June 13

Harvest: August 19 – October 30
Season vs crop: 114 grow days vs 90–120 needed
Typical frost (last spring – first fall): April 12 – November 8

Pumpkin in Detroit is doable with planning outdoors. 114 suitable days are enough for fast varieties (90 days) but not slow ones (120 days).

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 row114

Days to harvest90–120 days from seed

May 21 – Jun 13

Direct sow

Jun 14 – Aug 18

Grow outdoors

Aug 19 – Oct 30

Harvest

Activity	Window	Notes
Direct sow	May 21 – Jun 13	Plant outdoors in this window.
Grow outdoors	Jun 14 – Aug 18	Plants grow outdoors until harvest.
Harvest	Aug 19 – Oct 30	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 12

Low-risk last spring frostApril 22

Typical first fall frostNovember 8

Low-risk first fall frostOctober 30

Frost-free days209

Outdoor sow dateMay 21

Direct sow windowMay 21 – June 13

Suitable growing windowMay 21 – September 11 (114 days)

Expected harvestAugust 19 – October 30

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 Detroit, 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 Detroit

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 Detroit use ERA5-Land cell 42.33, -83.05. How we calculated this · Algorithm 2026-10-season-10.

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