Parsley · Philadelphia, Pennsylvania, United States
When to plant parsley in Philadelphia
Main outdoor window
31 Mar - 21 Apr
The window this page is built around.
Timed from last spring frost
14 April
In Philadelphia, on your chosen risk.
Ready to pick
9-29 Jun
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
17 Feb - 10 Mar
Eight weeks before your last frost, under cover or on a windowsill.
Sow for overwintering
30 Jun - 21 Jul
Counting back 104 days from your first frost so the crop matures in time.
Sow direct
31 Mar - 21 Apr
Two weeks before your last frost.
Plant out
31 Mar - 21 Apr
Two weeks before your last frost.
Harvest
9-29 Jun
Parsley through the year
Against the frost risk in Philadelphia
Why these dates
Germination takes three to four weeks. Sow indoors eight weeks before last frost or direct once soil warms; either way, patience is required.
Survives -10C and often overwinters to produce an early spring crop before running to seed in its second year.
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. Parsley are timed from 8 weeks before that frost for an indoor start, with planting out 2 weeks before 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 70 to 90 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Growing parsley in Philadelphia
When should I plant parsley in Philadelphia?
Aim for 31 Mar - 21 Apr in an average year. If you would rather not gamble on the weather, wait until 9-30 Apr - by then frost has finished in nine years out of ten.
When will parsley be ready to harvest in Philadelphia?
Expect to start picking around 9-29 Jun, based on 70 to 90 days to maturity from the planting date calculated for this location.
How much frost will parsley tolerate?
Survives -10C and often overwinters to produce an early spring crop before running to seed in its second year.