Coriander · Tacoma, Washington, United States
When to plant coriander in Tacoma
Main outdoor window
27 Feb - 9 Mar
The window this page is built around.
Timed from last spring frost
13 March
In Tacoma, on your chosen risk.
Ready to pick
13 Apr - 8 May
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 Tacoma
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.
Sow for autumn
7-28 Aug
Counting back 84 days from your first frost so the crop matures in time.
Sow direct
27 Feb - 9 Mar
Two weeks before your last frost.
Harvest
13 Apr - 8 May
Coriander through the year
Against the frost risk in Tacoma
Why these dates
Sow every two weeks from two weeks before last frost. The autumn sowing lasts far longer than any summer one, and in mild climates overwinters.
Takes -5C and grows happily in cool weather. Heat, not frost, is what ends a coriander plant.
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. Coriander are timed for direct sowing 2 weeks before it, and this page simply resolves those offsets against the frost date computed for Tacoma.
The median frost-free season here is 252 days, against 45 to 70 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Growing coriander in Tacoma
When should I plant coriander in Tacoma?
Aim for 27 Feb - 9 Mar in an average year. If you would rather not gamble on the weather, wait until 28 Mar - 7 Apr - by then frost has finished in nine years out of ten.
When will coriander be ready to harvest in Tacoma?
Expect to start picking around 13 Apr - 8 May, based on 45 to 70 days to maturity from the planting date calculated for this location.
How much frost will coriander tolerate?
Takes -5C and grows happily in cool weather. Heat, not frost, is what ends a coriander plant.