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Frost dates and planting calendar

Sunnyside, Grandview and Prosser, WA

The typical last spring frost in Sunnyside, Grandview and Prosser is May 1, and the first fall frost is around October 6. Plant peas from Mar 20; plant tomatoes from May 1.

Last spring frostMay 1Typical date. Frost is over by May 18 in 9 years out of 10.
First fall frostOctober 6Typical date. Comes as early as Sep 25 in 1 year out of 10.
Frost-free season158 daysYour growing season for frost-tender crops like tomatoes and squash.

NOAA 1991–2020 frost normals, Sunnyside station. Where these dates come from

About Sunnyside, Grandview and Prosser

Sunnyside, Grandview and Prosser sit in the lower Yakima Valley, known for wine grapes, hops, Concord grapes and orchards. Prosser calls itself the birthplace of Washington wine.

Chance of frost through the year

Frost over in 9 years out of 10: after May 18
Tomatoes go out May 1–29, under frost cover at first

In 9 years out of 10, the last spring frost has passed by May 18 and the first fall frost holds off until Sep 25.

What to plant now

Turn on JavaScript to see what's in season today. The full calendar is below.

East-side valleys. The Columbia Basin, Yakima Valley, Boise's Treasure Valley, Lewiston and other low valleys east of the Cascades. Hot, dry summers and quick spring warm-up. Warm crops go in earlier than west of the Cascades, and irrigation matters more than rain.

Gardening in the Yakima Valley and Columbia Basin. Summers are hot with very little rain, so irrigation is a must. The long, hot days suit melons, peppers and sweet corn, and spring winds can dry out or damage young plants, so shelter new transplants.

How the season in Sunnyside, Grandview and Prosser compares

With 158 frost-free days, Sunnyside, Grandview and Prosser have the 60th-longest season of the 86 Oregon, Washington and Idaho towns we cover. They run from 72 days in McCall to 330 days in Brookings and Gold Beach.

The typical last frost here, May 1, is in the middle of the towns we cover in the Yakima Valley and Columbia Basin: 35 days later than Walla Walla and 18 days earlier than Goldendale.

The gap between the typical last frost and the date it's over in 9 years out of 10 is 17 days, about average for the towns on this site. Frost after the typical date still happens about half the time, so plan on covering warm crops until May 18.

The season is long enough for every warm crop on our list, even pumpkins and sweet potatoes, to finish from a normal planting date.

For a fall and winter garden, sow carrots by July 28 and set out kale plants by August 11. Fall crops here are timed to the first frost (October 6 on average) and to shortening days.

Planting calendar

Pick a group to see when each plant goes in, or search for one.

Frost

Salad greens 7 plants

  • SpinachPlant seeds in the ground
    • Plant Mar 20 – Apr 24
    • Again for fall Aug 11 – Sep 1
  • LettucePlant seeds or young plants
    • Indoors Feb 6–20
    • Plant Mar 20 – May 15
    • Again for fall Aug 11–25
  • Swiss chardPlant seeds in the ground
    • Plant Apr 3 – May 29
    • Again for fall Jul 28 – Aug 11
  • ArugulaPlant seeds in the ground
    • Plant Mar 20 – May 1
    • Again for fall Aug 18 – Sep 8
  • CeleryPlant young plants (starts)
    • Indoors Feb 20 – Mar 6
    • Plant May 1 – Jun 5
  • MâchePlant seeds in the ground
    • Plant Mar 20 – Apr 24
    • Again for fall Aug 4 – Sep 8
  • RadicchioPlant seeds or young plants
    • Indoors Feb 20 – Mar 6
    • Plant Apr 3 – May 8
    • Again for fall Jun 30 – Jul 21

Cabbage family 9 plants

  • KalePlant young plants (starts)
    • Indoors Feb 20 – Mar 6
    • Plant Apr 3 – May 15
    • Again for fall Jul 28 – Aug 11
  • BroccoliPlant young plants (starts)
    • Indoors Feb 13–27
    • Plant Apr 3 – May 8
    • Again for fall Jul 14–28
  • CabbagePlant young plants (starts)
    • Indoors Feb 13–27
    • Plant Apr 3 – May 8
    • Again for fall Jul 14–28
  • CauliflowerPlant young plants (starts)
    • Indoors Feb 13–27
    • Plant Apr 3 – May 1
    • Again for fall Jul 7–21
  • Brussels sproutsPlant young plants (starts)
    • Indoors Feb 6–20
    • Plant Apr 3 – May 15
  • Bok choyPlant seeds or young plants
    • Indoors Feb 13–27
    • Plant Mar 20 – Apr 24
    • Again for fall Aug 11–25
  • KohlrabiPlant seeds or young plants
    • Indoors Feb 20 – Mar 6
    • Plant Apr 3 – May 15
    • Again for fall Aug 4–18
  • CollardsPlant young plants (starts)
    • Indoors Feb 20 – Mar 6
    • Plant Apr 3 – May 15
    • Again for fall Jul 28 – Aug 11
  • Mustard greensPlant seeds in the ground
    • Plant Mar 20 – May 1
    • Again for fall Aug 11 – Sep 1

Root vegetables 7 plants

  • RadishesPlant seeds in the ground
    • Plant Mar 20 – May 15
    • Again for fall Aug 25 – Sep 8
  • CarrotsPlant seeds in the ground
    • Plant Apr 3 – May 29
    • Again for fall Jul 14–28
  • BeetsPlant seeds in the ground
    • Plant Apr 3 – May 29
    • Again for fall Jul 28 – Aug 11
  • PotatoesPlant seed potatoes
    • Plant Apr 3 – May 15
  • TurnipsPlant seeds in the ground
    • Plant Mar 20 – May 1
    • Again for fall Aug 4–18
  • ParsnipsPlant seeds in the ground
    • Plant Apr 3 – May 15
  • Sweet potatoesPlant rooted cuttings (slips)
    • Plant May 10–31

    Frost possible until about May 18: keep frost cover handy.

Onion family 4 plants

  • OnionsPlant young plants or sets
    • Plant Mar 20 – Apr 24
  • GarlicPlant cloves
    • Fall Oct 1 – Nov 1
  • LeeksPlant young plants (starts)
    • Indoors Jan 23 – Feb 6
    • Plant Apr 3 – May 15
  • ShallotsPlant bulbs
    • Fall Oct 1 – Nov 1

Peas and beans 4 plants

  • PeasPlant seeds in the ground
    • Plant Mar 20 – May 1
  • Bush beansPlant seeds in the ground
    • Plant May 8 – Jun 19

    Frost possible until about May 18: keep frost cover handy.

  • Pole beansPlant seeds in the ground
    • Plant May 8 – Jun 12

    Frost possible until about May 18: keep frost cover handy.

  • Fava beansPlant seeds in the ground
    • Plant Mar 20 – Apr 24

Tomatoes and summer crops 6 plants

  • Sweet cornPlant seeds in the ground
    • Plant May 8 – Jun 12

    Frost possible until about May 18: keep frost cover handy.

  • TomatoesPlant young plants (starts)
    • Indoors Mar 6–20
    • Plant May 1–29

    Frost possible until about May 18: keep frost cover handy.

  • PeppersPlant young plants (starts)
    • Indoors Mar 1–15
    • Plant May 10–31

    Frost possible until about May 18: keep frost cover handy.

  • EggplantPlant young plants (starts)
    • Indoors Mar 1–15
    • Plant May 10–31

    Frost possible until about May 18: keep frost cover handy.

  • TomatillosPlant young plants (starts)
    • Indoors Mar 6–20
    • Plant May 1–29

    Frost possible until about May 18: keep frost cover handy.

  • Ground cherriesPlant young plants (starts)
    • Indoors Mar 13–27
    • Plant May 1–29

    Frost possible until about May 18: keep frost cover handy.

Squash, cucumbers and melons 5 plants

  • CucumbersPlant seeds or young plants
    • Indoors Apr 3–10
    • Plant May 1–29

    Frost possible until about May 18: keep frost cover handy.

  • Zucchini and summer squashPlant seeds or young plants
    • Indoors Apr 3–10
    • Plant May 1–29

    Frost possible until about May 18: keep frost cover handy.

  • Winter squashPlant seeds or young plants
    • Indoors Apr 3–10
    • Plant May 1–22

    Frost possible until about May 18: keep frost cover handy.

  • MelonsPlant seeds or young plants
    • Indoors Apr 12–19
    • Plant May 10–31

    Frost possible until about May 18: keep frost cover handy.

  • PumpkinsPlant seeds or young plants
    • Indoors Apr 3–10
    • Plant May 1–22

    Frost possible until about May 18: keep frost cover handy.

Herbs 13 plants

  • BasilPlant young plants (starts)
    • Indoors Mar 29 – Apr 12
    • Plant May 10 – Jun 7

    Frost possible until about May 18: keep frost cover handy.

  • CilantroPlant seeds in the ground
    • Plant Mar 20 – May 8
    • Again for fall Aug 18 – Sep 1
  • ParsleyPlant seeds or young plants
    • Indoors Feb 6–20
    • Plant Apr 3 – May 22
  • DillPlant seeds in the ground
    • Plant Apr 3 – Jun 5
  • ChivesPlant seeds or young plants
    • Indoors Feb 6–20
    • Plant Apr 3 – May 29
  • MintPlant young plants
    • Plant Apr 3 – May 29
  • RosemaryPlant young plants
    • Plant Apr 3 – May 22
  • ThymePlant young plants
    • Plant Apr 3 – May 29
  • OreganoPlant young plants
    • Plant Apr 3 – May 29
  • LavenderPlant young plants
    • Plant Apr 3 – May 29
  • SagePlant young plants
    • Plant Apr 3 – May 29
  • Lemon balmPlant young plants
    • Plant Apr 3 – May 29
  • TarragonPlant young plants
    • Plant Apr 3 – May 29

Berries 10 plants

  • StrawberriesPlant young plants
    • Plant Apr 3 – May 15
  • BlueberriesPlant potted or bare-root bushes
    • Plant Apr 3 – May 22
  • RaspberriesPlant bare-root canes
    • Plant Apr 3 – May 15
  • BlackberriesPlant bare-root or potted canes
    • Plant Mar 20 – May 8
  • GrapesPlant bare-root or potted vines
    • Plant Mar 20 – May 15
  • Hardy kiwiPlant potted vines
    • Plant Apr 3 – May 22
  • HoneyberriesPlant potted bushes
    • Plant Mar 20 – May 15
  • CurrantsPlant bare-root or potted bushes
    • Plant Mar 20 – May 15
  • GooseberriesPlant bare-root or potted bushes
    • Plant Mar 20 – May 15
  • ElderberriesPlant bare-root or potted shrubs
    • Plant Mar 20 – May 15

Perennial vegetables 5 plants

  • AsparagusPlant dormant crowns
    • Plant Apr 3 – May 15
  • RhubarbPlant dormant crowns
    • Plant Mar 20 – May 1
  • ArtichokesPlant young plants (starts)
    • Plant Apr 3 – May 15
  • SorrelPlant seeds or young plants
    • Plant Mar 20 – May 15
  • HorseradishPlant root cuttings
    • Plant Mar 20 – May 1

Fruit and nut trees 11 plants

  • Apple treesPlant bare-root or potted trees
    • Plant Mar 20 – May 15
  • Pear treesPlant bare-root or potted trees
    • Plant Mar 20 – May 15
  • Plum treesPlant bare-root or potted trees
    • Plant Mar 20 – May 15
  • Cherry treesPlant bare-root or potted trees
    • Plant Mar 20 – May 15
  • Fig treesPlant potted trees
    • Plant Apr 3 – May 29
  • Peach treesPlant bare-root or potted trees
    • Plant Mar 20 – May 15
  • Hazelnut treesPlant bare-root or potted trees
    • Plant Mar 20 – May 15
  • Persimmon treesPlant bare-root or potted trees
    • Plant Mar 20 – May 15
  • Asian pear treesPlant bare-root or potted trees
    • Plant Mar 20 – May 15
  • Quince treesPlant bare-root or potted trees
    • Plant Mar 20 – May 15
  • Mulberry treesPlant bare-root or potted trees
    • Plant Mar 20 – May 15

Native plants 15 plants

Flowers 13 plants

  • DahliasPlant tubers
    • Plant May 1–29

    Frost possible until about May 18: keep frost cover handy.

  • SunflowersPlant seeds in the ground
    • Plant May 8 – Jun 19

    Frost possible until about May 18: keep frost cover handy.

  • Sweet peasPlant seeds in the ground
    • Plant Mar 20 – Apr 24
  • TulipsPlant bulbs
    • Fall Oct 1 – Nov 1
  • DaffodilsPlant bulbs
    • Fall Oct 1 – Nov 1
  • ZinniasPlant seeds in the ground
    • Plant May 8 – Jun 19

    Frost possible until about May 18: keep frost cover handy.

  • PeoniesPlant bare-root divisions
    • Fall Oct 1 – Nov 1
  • CosmosPlant seeds or young plants
    • Indoors Mar 27 – Apr 10
    • Plant May 8 – Jun 19

    Frost possible until about May 18: keep frost cover handy.

  • NasturtiumsPlant seeds in the ground
    • Plant May 8 – Jun 19

    Frost possible until about May 18: keep frost cover handy.

  • MarigoldsPlant seeds or young plants
    • Indoors Mar 20 – Apr 3
    • Plant May 1 – Jun 5

    Frost possible until about May 18: keep frost cover handy.

  • CalendulaPlant seeds in the ground
    • Plant Apr 3 – May 22
    • Again for fall Jul 28 – Aug 11
  • RanunculusPlant soaked corms
    • Plant Apr 3 – May 8
  • SnapdragonsPlant seeds or young plants
    • Indoors Jan 23 – Feb 6
    • Plant Apr 3 – May 15

New to this? Read the beginner's guide or look up a term in the glossary.

ZIP codes that use these dates: 98944, 98930, 99350, 98935, 98932. Look up another ZIP.

Where these dates come from

The frost dates for Sunnyside, Grandview and Prosser come from the NOAA weather station in Sunnyside, at 750 feet. It's the closest weather station to Sunnyside, Grandview and Prosser with NOAA's 1991–2020 frost records. It's a NOAA cooperative station, not an airport station.

They're NOAA's 1991–2020 climate normals: 30-year averages, not a forecast. How we pick each town's station.

Common questions about frost in Sunnyside, Grandview and Prosser

When is the last frost in Sunnyside, Grandview and Prosser?

May 1 in a typical year. Frost is over by May 18 in 9 years out of 10, Tender plants like tomatoes wait longer than that, for warm soil: see the tomato question below.

When is the first frost in Sunnyside, Grandview and Prosser?

Around October 6. It comes as early as September 25 in 1 year out of 10.

When can I plant tomatoes in Sunnyside, Grandview and Prosser?

Set out tomato plants May 1–29, after starting seeds indoors Mar 6–20. Keep frost cover handy until about May 18.

When should I plant garlic in Sunnyside, Grandview and Prosser?

Plant garlic cloves Oct 1 – Nov 1, and harvest next summer when the lower leaves turn brown.

How long is the growing season in Sunnyside, Grandview and Prosser?

About 158 frost-free days, shorter than most of the 86 Oregon, Washington and Idaho towns we cover.

Nearby areas with similar weather

All town calendars or look up your ZIP.