Winter melon · Philadelphia, Pennsylvania, United States
When to plant winter melons in Philadelphia
Main outdoor window
28 Apr - 19 May
The window this page is built around.
Timed from last spring frost
14 April
In Philadelphia, on your chosen risk.
Ready to pick
1 Sep - 30 Nov
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
10-31 Mar
Five weeks before your last frost, under cover or on a windowsill.
Plant out
28 Apr - 19 May
Two weeks after your last frost.
Harvest
1 Sep - 30 Nov
Winter melons through the year
Against the frost risk in Philadelphia
Why these dates
Start indoors five weeks before the last frost and plant out two weeks after it. It needs a longer warm run than a pumpkin, so it is marginal in cool summers.
Killed at 0C. The wax bloom that makes it store so well only develops on fully mature fruit, which needs the whole season.
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. Winter melons are timed from 5 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 110 to 140 days to maturity for this crop counted from planting out. That margin is what decides whether a late sowing is worth attempting.
Also in Philadelphia
Other vegetables to time
Growing winter melons in Philadelphia
When should I plant winter melons in Philadelphia?
Aim for 28 Apr - 19 May in an average year. If you would rather not gamble on the weather, wait until 7-28 May - by then frost has finished in nine years out of ten.
When will winter melons be ready to harvest in Philadelphia?
Expect to start picking around 1 Sep - 30 Nov, based on 110 to 140 days to maturity from the planting date calculated for this location.
How much frost will winter melons tolerate?
Killed at 0C. The wax bloom that makes it store so well only develops on fully mature fruit, which needs the whole season.