Washington planting calendar

When to put transplants or seed in the ground in covered areas of Washington, worked out from the average last spring and first fall frost for each USDA zone in the state, and what to line up before you commit ground. This page covers only the listed Zone 6–9 areas, not the whole state. Elevation changes frost dates fast here, so check your own last-frost date against the zone average. Written for farms that sell what they grow.

Your zone in Washington: frost dates

Zones 6b–8b run through Washington. Frost dates are long-term averages for planning, not a forecast for your field.

  • Zone 6b
    Spokane and the eastern uplands
    Last frost
    ~April 24
    First frost
    ~October 8
    Frost-free days
    167
    Winter low
    -5°F to 0°F
  • Zone 7a
    Yakima and Wenatchee
    Last frost
    ~April 15
    First frost
    ~October 15
    Frost-free days
    183
    Winter low
    0°F to 5°F
  • Zone 7b
    Tri-Cities and the Columbia Basin
    Last frost
    ~April 8
    First frost
    ~October 22
    Frost-free days
    197
    Winter low
    5°F to 10°F
  • Zone 8b
    Skagit Valley, Seattle and Puget Sound
    Last frost
    ~March 15
    First frost
    ~November 15
    Frost-free days
    245
    Winter low
    15°F to 20°F

What it costs to grow an acre in Washington

No published Washington budget is transcribed here yet, so this page shows planting dates only — we do not publish cost figures we cannot source. Neighboring state budgets from NC State, UGA and UF/IFAS are on the crop profitability page.

Every figure is transcribed from a published land-grant enterprise budget for that state. These are planning budgets built from grower panels and dealer quotes, not surveys of what farms actually spent — your invoices override them everywhere they exist.

When to plant Washington's main crops

Calculated for Zone 7b (Tri-Cities and the Columbia Basin). Pick your own zone on the crop page.

  • Tomatoes
    April 15 – May 6
    July 6 – August 3
  • Peppers
    April 22 – May 13
    July 8 – August 5
  • Sweet corn
    April 8 – April 29
    June 29 – July 27
  • Cucumbers
    April 15 – May 6
    June 16 – July 14
  • Summer squash
    April 15 – May 6
    June 11 – July 9
  • Green beans (bush)
    April 8 – April 29
    June 9 – July 7
  • Cabbage
    March 11 – April 1
    June 1 – June 29
  • Broccoli
    March 11 – April 1
    May 22 – June 19
  • Kale
    March 4 – March 25
    May 5 – June 2
  • Carrots
    March 11 – April 1
    May 27 – June 24
  • Lettuce
    March 4 – March 25
    April 25 – May 23
  • Strawberries
    September 16 – October 7
    March 22 – April 19

What zone is my farm?

  • SpokaneZone 6b
  • YakimaZone 7a
  • PascoZone 7b
  • Mount VernonZone 8b
  • SeattleZone 8b

If your farm sits in a zone that is not listed here, start from the calendar index and pick the closest match, then confirm with your county extension office.

Before you commit ground

A planting date tells you when a crop can grow — not whether it pays. Work out your breakeven price, then line up who is buying before you plant.

Washington planting and cost questions

What USDA planting zone is Spokane, Washington?
The calendar carries Spokane in Zone 6b. Average last spring frost is around April 24 and average first fall frost around October 8, which is about 167 frost-free days.
What USDA planting zone is Yakima, Washington?
The calendar carries Yakima in Zone 7a. Average last spring frost is around April 15 and average first fall frost around October 15, which is about 183 frost-free days.
When should I plant tomatoes in Washington?
In Zone 7b (Tri-Cities and the Columbia Basin), April 15 – May 6 july 6 – august 3

Other state pages

Dates are calculated from average first and last frost dates for each zone. Your microclimate, elevation and soil temperature can shift any window by a week or more — treat these as starting points and keep your own records.