Pumpkin · Philadelphia, Pennsylvania, United States
When to plant pumpkins in Philadelphia
Main outdoor window
28 Apr - 12 May
The window this page is built around.
Timed from last spring frost
14 April
In Philadelphia, on your chosen risk.
Ready to pick
27 Jul - 26 Aug
If you plant at the start of the window.
The average last frost. Half of all years are later than this.
Step by step in Philadelphia
Each window is a range, not a single day. Earlier in the range buys you a longer season; later in it buys you a safer one.
Start indoors
24 Mar - 7 Apr
Three weeks before your last frost, under cover or on a windowsill.
Sow direct
28 Apr - 12 May
Two weeks after your last frost.
Plant out
28 Apr - 12 May
Two weeks after your last frost.
Harvest
27 Jul - 26 Aug
Pumpkins through the year
Against the frost risk in Philadelphia
Why these dates
If your frost-free season is shorter than 110 days, start indoors and choose a smaller cultivar. Giant pumpkins are a long-season crop, not a beginner one.
Foliage dies at the first frost, but mature fruit tolerates a light touch. Harvest before a hard frost or the flesh will not store.
Seed packets and extension guides express timing as weeks either side of the last spring frost, because that is the only reference point that travels. Pumpkins are timed from 3 weeks before that frost for an indoor start, with planting out 2 weeks after it, and this page simply resolves those offsets against the frost date computed for Philadelphia.
The median frost-free season here is 202 days, against 90 to 120 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Philadelphia
Other vegetables to time
Growing pumpkins in Philadelphia
When should I plant pumpkins in Philadelphia?
Aim for 28 Apr - 12 May in an average year. If you would rather not gamble on the weather, wait until 7-21 May - by then frost has finished in nine years out of ten.
When will pumpkins be ready to harvest in Philadelphia?
Expect to start picking around 27 Jul - 26 Aug, based on 90 to 120 days to maturity from the planting date calculated for this location.
How much frost will pumpkins tolerate?
Foliage dies at the first frost, but mature fruit tolerates a light touch. Harvest before a hard frost or the flesh will not store.