FrostCal

When to Plant Watermelon in Oregon

In a typical Oregon location, start seeds indoors Mar 6 – Mar 13, then transplant outdoors Apr 17 – Apr 24. Across the state, the outdoor planting window starts as early as Feb 25 in Beaverton and as late as Jun 23 in Altamont.

Method Start indoors, then transplant
Days to maturity 70–90 days

Needs warm soil (65F+); start indoors 3-4 weeks before last frost, transplant 2-3 weeks after last frost.

Watermelon Planting Dates by City

CityStart indoorsTransplant
PortlandJan 28 – Feb 4Mar 11 – Mar 18
EugeneMar 14 – Mar 21Apr 25 – May 2
SalemMar 6 – Mar 13Apr 17 – Apr 24
GreshamFeb 16 – Feb 23Mar 30 – Apr 6
HillsboroMar 19 – Mar 26Apr 30 – May 7
BeavertonJan 14 – Jan 21Feb 25 – Mar 4
BendMay 9 – May 16Jun 20 – Jun 27
MedfordMar 11 – Mar 18Apr 22 – Apr 29
SpringfieldMar 14 – Mar 21Apr 25 – May 2
CorvallisMar 20 – Mar 27May 1 – May 8
AlbanyMar 20 – Mar 27May 1 – May 8
TigardMar 4 – Mar 11Apr 15 – Apr 22
AlohaJan 14 – Jan 21Feb 25 – Mar 4
Lake OswegoFeb 18 – Feb 25Apr 1 – Apr 8
KeizerMar 6 – Mar 13Apr 17 – Apr 24
Grants PassMar 11 – Mar 18Apr 22 – Apr 29
Oregon CityFeb 18 – Feb 25Apr 1 – Apr 8
McMinnvilleMar 8 – Mar 15Apr 19 – Apr 26
RedmondMay 12 – May 19Jun 23 – Jun 30
TualatinMar 4 – Mar 11Apr 15 – Apr 22
West LinnFeb 18 – Feb 25Apr 1 – Apr 8
WoodburnFeb 16 – Feb 23Mar 30 – Apr 6
Forest GroveMar 19 – Mar 26Apr 30 – May 7
NewbergFeb 21 – Feb 28Apr 4 – Apr 11
WilsonvilleFeb 18 – Feb 25Apr 1 – Apr 8
RoseburgFeb 23 – Mar 2Apr 6 – Apr 13
Klamath FallsMay 12 – May 19Jun 23 – Jun 30
AshlandApr 8 – Apr 15May 20 – May 27
MilwaukieJan 28 – Feb 4Mar 11 – Mar 18
BethanyMar 19 – Mar 26Apr 30 – May 7

Showing the 30 most populous of 68 Oregon cities. Dates are estimates from each city's NOAA frost normals and university extension timing guidelines. See all Oregon cities.

Frequently Asked Questions

When should I plant watermelon in Oregon?

In a typical Oregon location, start seeds indoors Mar 6 – Mar 13, then transplant outdoors Apr 17 – Apr 24. Across the state, the outdoor planting window starts as early as Feb 25 in Beaverton and as late as Jun 23 in Altamont.

When is the last frost in Oregon?

The average last spring frost in Oregon ranges from February 11 in Beaverton to June 9 in Altamont, based on NOAA 1991–2020 climate normals.

How long do watermelon take to grow?

Watermelon typically take 70–90 days from planting to harvest. Needs warm soil (65F+); start indoors 3-4 weeks before last frost, transplant 2-3 weeks after last frost.

Other Crops in Oregon

When to plant watermelon in other states

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