When to plant onions in Washington

Onions
Plant out in Seattle
Jan 25–Feb 15

Across Washington the window opens between January 19 and March 27. Find your city below; the dates follow each town's own average last frost.

Start indoors, Seattle
Dec 14–Jan 11
Plant out, Seattle
Jan 25–Feb 15
Last frost, Seattle
Mar 8

Start seeds indoors 8–12 weeks before the last frost; plant out 3–6 weeks before the last frost. Northern gardens need long-day varieties and southern gardens need short-day ones. A wrong pick gives small bulbs.

Onions planting dates by city

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
JanFebMarAprMayJunJulAugSepOctNovDec
SeattleJan 25–Feb 15
SpokaneMar 15–Apr 5
TacomaJan 25–Feb 15
VancouverFeb 15–Mar 8
BellevueJan 25–Feb 15
KentFeb 6–Feb 27
EverettFeb 10–Mar 3
Spokane ValleyMar 15–Apr 5
RentonJan 30–Feb 20
Federal WayJan 25–Feb 15
YakimaFeb 25–Mar 18
KirklandJan 25–Feb 15
BellinghamFeb 18–Mar 11
KennewickFeb 14–Mar 7
AuburnFeb 6–Feb 27
PascoMar 16–Apr 6
RedmondJan 25–Feb 15
MarysvilleFeb 10–Mar 3
South HillFeb 28–Mar 21
ShorelineJan 25–Feb 15
SammamishFeb 16–Mar 9
RichlandFeb 23–Mar 16
LakewoodJan 28–Feb 18
LaceyMar 18–Apr 8
OlympiaMar 18–Apr 8
BothellJan 25–Feb 15
BurienJan 19–Feb 9
BremertonFeb 15–Mar 8
EdmondsJan 26–Feb 16
PuyallupFeb 28–Mar 21
All 76 cities
CityStart indoorsPlant outLast frost
SeattleDec 14 to Jan 11Jan 25 to Feb 15Mar 8
SpokaneFeb 1 to Mar 1Mar 15 to Apr 5Apr 26
TacomaDec 14 to Jan 11Jan 25 to Feb 15Mar 8
VancouverJan 4 to Feb 1Feb 15 to Mar 8Mar 29
BellevueDec 14 to Jan 11Jan 25 to Feb 15Mar 8
KentDec 26 to Jan 23Feb 6 to Feb 27Mar 20
EverettDec 30 to Jan 27Feb 10 to Mar 3Mar 24
Spokane ValleyFeb 1 to Mar 1Mar 15 to Apr 5Apr 26
RentonDec 19 to Jan 16Jan 30 to Feb 20Mar 13
Federal WayDec 14 to Jan 11Jan 25 to Feb 15Mar 8
YakimaJan 14 to Feb 11Feb 25 to Mar 18Apr 8
KirklandDec 14 to Jan 11Jan 25 to Feb 15Mar 8
BellinghamJan 7 to Feb 4Feb 18 to Mar 11Apr 1
KennewickJan 3 to Jan 31Feb 14 to Mar 7Mar 28
AuburnDec 26 to Jan 23Feb 6 to Feb 27Mar 20
PascoFeb 2 to Mar 2Mar 16 to Apr 6Apr 27
RedmondDec 14 to Jan 11Jan 25 to Feb 15Mar 8
MarysvilleDec 30 to Jan 27Feb 10 to Mar 3Mar 24
South HillJan 17 to Feb 14Feb 28 to Mar 21Apr 11
ShorelineDec 14 to Jan 11Jan 25 to Feb 15Mar 8
SammamishJan 5 to Feb 2Feb 16 to Mar 9Mar 30
RichlandJan 12 to Feb 9Feb 23 to Mar 16Apr 6
LakewoodDec 17 to Jan 14Jan 28 to Feb 18Mar 11
LaceyFeb 4 to Mar 4Mar 18 to Apr 8Apr 29
OlympiaFeb 4 to Mar 4Mar 18 to Apr 8Apr 29
BothellDec 14 to Jan 11Jan 25 to Feb 15Mar 8
BurienDec 8 to Jan 5Jan 19 to Feb 9Mar 2
BremertonJan 4 to Feb 1Feb 15 to Mar 8Mar 29
EdmondsDec 15 to Jan 12Jan 26 to Feb 16Mar 9
PuyallupJan 17 to Feb 14Feb 28 to Mar 21Apr 11
LynnwoodDec 15 to Jan 12Jan 26 to Feb 16Mar 9
Lake StevensDec 30 to Jan 27Feb 10 to Mar 3Mar 24
IssaquahDec 19 to Jan 16Jan 30 to Feb 20Mar 13
ParklandDec 14 to Jan 11Jan 25 to Feb 15Mar 8
LongviewJan 14 to Feb 11Feb 25 to Mar 18Apr 8
WenatcheeJan 10 to Feb 7Feb 21 to Mar 14Apr 4
University PlaceDec 17 to Jan 14Jan 28 to Feb 18Mar 11
Mount VernonDec 30 to Jan 27Feb 10 to Mar 3Mar 24
GrahamJan 17 to Feb 14Feb 28 to Mar 21Apr 11
SeaTacDec 8 to Jan 5Jan 19 to Feb 9Mar 2
SpanawayJan 17 to Feb 14Feb 28 to Mar 21Apr 11
Walla WallaJan 2 to Jan 30Feb 13 to Mar 6Mar 27
PullmanFeb 11 to Mar 11Mar 25 to Apr 15May 6
Des MoinesDec 8 to Jan 5Jan 19 to Feb 9Mar 2
OrchardsFeb 1 to Mar 1Mar 15 to Apr 5Apr 26
Maple ValleyJan 26 to Feb 23Mar 9 to Mar 30Apr 20
TumwaterFeb 4 to Mar 4Mar 18 to Apr 8Apr 29
CamasDec 22 to Jan 19Feb 2 to Feb 23Mar 16
Moses LakeFeb 2 to Mar 2Mar 16 to Apr 6Apr 27
Mill Creek EastDec 15 to Jan 12Jan 26 to Feb 16Mar 9
Mountlake TerraceDec 14 to Jan 11Jan 25 to Feb 15Mar 8
Mercer IslandDec 19 to Jan 16Jan 30 to Feb 20Mar 13
Bainbridge IslandJan 4 to Feb 1Feb 15 to Mar 8Mar 29
KenmoreDec 14 to Jan 11Jan 25 to Feb 15Mar 8
FredericksonJan 17 to Feb 14Feb 28 to Mar 21Apr 11
Oak HarborDec 19 to Jan 16Jan 30 to Feb 20Mar 13
North LynnwoodDec 15 to Jan 12Jan 26 to Feb 16Mar 9
Battle GroundFeb 1 to Mar 1Mar 15 to Apr 5Apr 26
EastmontDec 15 to Jan 12Jan 26 to Feb 16Mar 9
Union Hill-Novelty HillDec 14 to Jan 11Jan 25 to Feb 15Mar 8
Cottage LakeJan 23 to Feb 20Mar 6 to Mar 27Apr 17
Hazel DellFeb 1 to Mar 1Mar 15 to Apr 5Apr 26
Martha LakeDec 15 to Jan 12Jan 26 to Feb 16Mar 9
Bonney LakeJan 17 to Feb 14Feb 28 to Mar 21Apr 11
ArlingtonJan 28 to Feb 25Mar 11 to Apr 1Apr 22
TukwilaDec 8 to Jan 5Jan 19 to Feb 9Mar 2
Silver FirsDec 15 to Jan 12Jan 26 to Feb 16Mar 9
CovingtonJan 26 to Feb 23Mar 9 to Mar 30Apr 20
Five CornersFeb 1 to Mar 1Mar 15 to Apr 5Apr 26
EllensburgFeb 13 to Mar 13Mar 27 to Apr 17May 8
MukilteoDec 15 to Jan 12Jan 26 to Feb 16Mar 9
SilverdaleJan 4 to Feb 1Feb 15 to Mar 8Mar 29
Bothell WestDec 15 to Jan 12Jan 26 to Feb 16Mar 9
Mill CreekDec 15 to Jan 12Jan 26 to Feb 16Mar 9
Port AngelesDec 18 to Jan 15Jan 29 to Feb 19Mar 12
MonroeJan 23 to Feb 20Mar 6 to Mar 27Apr 17

Questions

When should I plant onions in Washington?

In Seattle, plant out from January 25 to February 15. Across Washington the window opens between January 19 and March 27, depending on the local last frost.

How is this date worked out?

Start seeds indoors 8–12 weeks before the last frost; plant out 3–6 weeks before the last frost. Frost dates are NOAA 1991–2020 averages for the weather station nearest each city.

More for Washington

Onions in other states

Frost dates for every city in Washington