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Kennewick, WA Planting Calendar

The last spring frost in Kennewick usually comes around Mar 21 and the first fall frost around Nov 5, a growing season of about 229 days. Start tomatoes indoors Feb 7 – Feb 21 and plant them outside Apr 4 – Apr 18.

Last spring frostMar 21
First fall frostNov 5
Growing season229 days

When to plant vegetables in Kennewick

VegetableStart seeds indoorsPlant outsideFall crop
TomatoesFeb 7 – Feb 21Apr 4 – Apr 18—
PeppersJan 31 – Feb 14Apr 11 – Apr 25—
EggplantJan 31 – Feb 14Apr 11 – Apr 25—
Cucumbers—Apr 4 – Apr 18—
Zucchini & summer squash—Apr 4 – Apr 18—
Pumpkins & winter squash—Apr 11 – Apr 25—
Green beans—Apr 4 – Apr 18Aug 13 – Aug 27
Sweet corn—Apr 4 – Apr 18—
BasilFeb 21 – Mar 7Apr 4 – Apr 18—
LettuceJan 24 – Feb 7Feb 21 – Apr 4Sep 10 – Sep 24
Spinach—Feb 7 – Feb 28Sep 10 – Sep 24
Peas—Feb 7 – Feb 28Aug 27 – Sep 10
Carrots—Feb 21 – Mar 28Aug 13 – Aug 27
Radishes—Feb 14 – Apr 4Sep 24 – Oct 8
BroccoliJan 10 – Jan 24Feb 21 – Mar 7Aug 13 – Aug 27
KaleJan 24 – Feb 7Feb 14 – Feb 28Aug 27 – Sep 10
Onions—Feb 21 – Mar 7—
Potatoes—Feb 28 – Mar 28—
Garlic——Oct 22 – Nov 26

Dates count from the median frost dates (2016–2025) for Kennewick. In a cold spring, wait a week; in a warm one you can go a week early.

Month-by-month planting in Kennewick

  1. JanuaryStart indoors: Peppers, Eggplant, Lettuce, Broccoli, Kale
  2. FebruaryStart indoors: Tomatoes, Peppers, Eggplant, Basil, Lettuce, KalePlant outside: Lettuce, Spinach, Peas, Carrots, Radishes, Broccoli, Kale, Onions, Potatoes
  3. MarchStart indoors: BasilPlant outside: Lettuce, Carrots, Radishes, Broccoli, Onions, Potatoes
  4. AprilPlant outside: Tomatoes, Peppers, Eggplant, Cucumbers, Zucchini & summer squash, Pumpkins & winter squash, Green beans, Sweet corn, Basil, Lettuce, Radishes
  5. MayPlan, order seeds and prepare beds.
  6. JunePlan, order seeds and prepare beds.
  7. JulyPlan, order seeds and prepare beds.
  8. AugustPlant outside: Green beans, Peas, Carrots, Broccoli, Kale
  9. SeptemberPlant outside: Lettuce, Spinach, Peas, Radishes, Kale
  10. OctoberPlant outside: Radishes, Garlic
  11. NovemberPlant outside: Garlic
  12. DecemberPlan, order seeds and prepare beds.

Tools for this season

Seed starting kitTrays with humidity domes for starting seeds indoors.See options on AmazonLED grow lightKeeps indoor seedlings short and sturdy.See options on AmazonFrost clothCovers tender plants on a surprise frost night.See options on AmazonSoil thermometerCheck the soil at 4 inches before you spread anything.See options on Amazon

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Frequently asked questions

When is the last frost in Kennewick?

The median last spring frost is Mar 21 and the median first fall frost is Nov 5, based on 2016–2025 weather data.

When should I plant tomatoes in Kennewick?

Start seeds indoors Feb 7 – Feb 21 and set plants outside Apr 4 – Apr 18, once nights stay above 50°F.

When should I plant a fall garden in Kennewick?

Sow or transplant cool-season crops 6 to 12 weeks before the first fall frost (around Nov 5): broccoli and carrots first, lettuce, spinach and radishes last.

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