Basil · Tacoma, Washington, United States
When to plant basil in Tacoma
Main outdoor window
27 Mar - 10 Apr
The window this page is built around.
Timed from last spring frost
13 March
In Tacoma, on your chosen risk.
Ready to pick
16 May - 5 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 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.
Start indoors
13-27 Feb
Four weeks before your last frost, under cover or on a windowsill.
Sow direct
27 Mar - 10 Apr
Two weeks after your last frost.
Plant out
27 Mar - 10 Apr
Two weeks after your last frost.
Harvest
16 May - 5 Jun
Basil through the year
Against the frost risk in Tacoma
Why these dates
Plant out two weeks after last frost, once nights are reliably above 12C. A second sowing in midsummer replaces plants that have gone to flower.
Damaged at 1C, before any actual frost forms. If your forecast shows 2C, basil should already be indoors.
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. Basil are timed from 4 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 Tacoma.
The median frost-free season here is 252 days, against 50 to 70 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Growing basil in Tacoma
When should I plant basil in Tacoma?
Aim for 27 Mar - 10 Apr in an average year. If you would rather not gamble on the weather, wait until 25 Apr - 9 May - by then frost has finished in nine years out of ten.
When will basil be ready to harvest in Tacoma?
Expect to start picking around 16 May - 5 Jun, based on 50 to 70 days to maturity from the planting date calculated for this location.
How much frost will basil tolerate?
Damaged at 1C, before any actual frost forms. If your forecast shows 2C, basil should already be indoors.