When To Plant Vegetables In Washington State

Getting your timing right is the single most important step for a great garden in Washington. If you want a continuous, healthy harvest, you need to know when to plant vegetables in Washington state. Our unique climate, with its wet springs, dry summers, and distinct east-west differences, makes a planting calendar essential.

This guide will walk you through the key factors and provide a clear, month-by-month plan. We’ll help you understand your specific microclimate so you can plant with confidence.

This core schedule is your starting point. Remember, these are general guidelines for the more temperate western regions and the hotter, drier east. Your local frost dates are your best friend here.

Understanding Your Washington Growing Zone

Washington isn’t just one garden. It’s many. The Cascade Mountains split the state into two major climate zones.

Western Washington (Zones 8a-9a): Mild, wet winters and cool, dry summers. The maritime influence means a long, productive spring and fall, but cooler summer soil temps. Frost dates can vary widely even within this region.
Eastern Washington (Zones 5b-7a): Continental climate with cold winters and hot, dry summers. The growing season is shorter but intensely sunny and warm. Timing for heat-lovers is different here.

Always check your last average spring frost date and your first average fall frost date. Your local county extension service website has the most accurate info for your town.

Spring Planting (February – May)

This is the busiest seeding and planting time. The goal is to get crops established in cool soil so they mature before summer heat or after it fades.

Very Early Spring (Late Feb – March)

As soon as the soil is workable (not soggy), you can plant these hardy crops. They tolerate light frosts.

Direct Seed: Peas, spinach, radishes, arugula, kale, and parsnips.
Transplant: Onion sets, garlic (planted in fall, but now is when it resumes growth), and bare-root asparagus crowns.

In Eastern WA, wait until the ground thaws completely, often in March or early April.

Mid-Spring (April)

Soil is warming up. This is prime time for many cool-season vegetables.

Direct Seed: Beets, carrots, Swiss chard, lettuce, and turnips. You can plant another round of peas for a later harvest.
Start Indoors: For summer crops like tomatoes, peppers, and eggplants, get those seeds started inside now if you haven’t already.

Late Spring (May)

After the danger of frost has passed—typically mid-May in Western WA and late May in Eastern WA—it’s safe for warm-season crops.

Direct Seed: Beans, corn, squash (summer & winter), and cucumbers. Wait until soil is above 60°F for good germination.
Transplant: Harden off and plant your tomato, pepper, eggplant, and basil seedlings. Also transplant any remaining broccoli or cabbage starts.

Summer Planting (June – July)

Summer is for maintaining and succession planting. Don’t let your garden space go empty!

Succession Sow: As you harvest radishes or lettuce, replant that space with quick-growing beans, more carrots, or another round of salad greens (provide afternoon shade to prevent bolting).
Plant for Fall: This is crucial. In July, start seeds indoors for fall brassicas like broccoli, cauliflower, and Brussels sprouts. By late July, you can direct seed fall beets, carrots, and bush beans.

Keep everything well-watered, especially in Eastern Washington’s arid heat. Mulching is your best friend for conserving moisture.

Fall & Winter Planting (August – October)

Washington’s mild fall, especially in the west, is a secret second spring. Many crops thrive in the cooling temperatures.

Late Summer (August)

Direct seed cool-weather crops that will mature in the fall. They often taste sweeter after a light frost.

Spinach, lettuce, kale, scallions, and radishes.
Transplant your broccoli and cauliflower seedlings into the garden by mid-August.

Early Fall (September – October)

Plant overwintering crops and garlic. These will grow roots in the fall, go dormant in winter, and surge in early spring.

Plant Garlic: Mid-October is ideal. Break a bulb into cloves and plant them pointy-side up, about 2 inches deep.
Overwintering Crops: Sow seeds of spinach and certain onion varieties. They’ll be ready for a very early spring harvest.
You can also use cold frames or row covers to extend the harvest of crops like lettuce and chard well into winter.

Step-by-Step: Creating Your Personal Planting Calendar

Find Your Frost Dates: Note the average last spring frost and first fall frost for your exact location.
Work Backwards: For transplants like tomatoes, check the seed packet (e.g., “start indoors 6-8 weeks before last frost”). Count back from your last frost date to find your seeding date.
Use Soil Temperature: Invest in a soil thermometer. Warm-season crops need warm soil. Planting corn in 55°F soil will lead to poor germination.
Keep a Garden Journal: Note when you planted, what variety, and how it performed. This is your most valuable tool for refining your timing each year.

Common Timing Mistakes to Avoid

Planting Too Early: Impatience is a gardener’s biggest enemy. Cold, wet soil rots seeds and stunts plants. Warm-season plants set outside too early won’t grow and are suseptible to disease.
Missing Succession Windows: An empty garden bed in July is a wasted opportunity. Always have the next crop ready to go in.
Ignoring Crop Days to Maturity: When planting for fall, choose varieties with a “days to maturity” that is shorter than the number of days between your planting date and your average first frost. Add a 2-week buffer for slowing fall growth.
Forgetting to Rotate: Don’t plant the same family of vegetables (e.g., tomatoes, peppers, eggplant) in the same spot year after year. It depletes soil and encourages pests.

FAQ: Your Washington Planting Questions Answered

When is the best time to plant tomatoes in Washington?
Start seeds indoors 6-8 weeks before your last spring frost. Transplant hardened-off seedlings outdoors after all danger of frost has passed, when night temps stay above 50°F. For Western WA, this is usually mid-to-late May; for Eastern WA, late May or early June.

What can I plant in early spring in Washington?
The earliest crops include peas, spinach, radishes, kale, and lettuce. You can plant these as soon as the soil is workable, often in late February or March on the west side, and April in the east.

How do I extend my growing season in Washington?
Use season extension tools. Cold frames, row covers, and cloches protect plants from light frosts in spring and fall. They allow you to start earlier and harvest later, sometimes year-round for hardy greens.

Is it to late to plant a garden in July?
Not at all! July is perfect for planting fall harvest crops like carrots, beets, bush beans, and starting broccoli and cauliflower indoors for transplant. Quick-maturing summer squash can also still be planted in early July.

What vegetables grow best in Western Washington?
Cool-season crops excel: leafy greens, broccoli, cauliflower, peas, carrots, beets, and potatoes. With care, summer crops like tomatoes, cucumbers, and beans also do well, especially in sun-trapping locations.

What vegetables grow best in Eastern Washington?
Heat-loving crops thrive with the intense sunshine: tomatoes, peppers, eggplant, corn, melons, winter squash, and dry beans. You can also grow fantastic cool-season crops in the spring and fall shoulders of the season.

By aligning your planting with Washington’s distinct seasons and your local conditions, you set your garden up for maximum productivty. Start with the core dates, observe your garden’s response, and adjust your calendar each year. The reward is a long, bountiful harvest from spring straight through to fall.