Best Time To Plant Cilantro In Washington

Washington’s cool, wet springs make cilantro planting a race against time before summer heat arrives. Knowing the best time to plant cilantro in washington is the difference between a lush harvest and a bitter, bolted mess. This guide gives you the exact timing, step-by-step methods, and local tips to succeed.

Cilantro thrives in cool weather. It hates heat. In Washington, your window is narrow but productive. Plant too early and frost kills it. Plant too late and the sun scorches it. Let’s get the timing right.

The ideal window for most of Washington is from mid-March to early May for spring planting, and again from late August to mid-September for a fall crop. This timing avoids both hard frost and intense summer heat. Your specific location matters—western Washington runs cooler and wetter, while eastern Washington heats up faster.

For western Washington (Seattle, Tacoma, Olympia), aim for late March to mid-April. The soil is workable, and rain keeps it moist. For eastern Washington (Spokane, Yakima, Tri-Cities), wait until early to mid-April. The risk of a late frost is higher there.

Fall planting is a secret weapon. Cilantro loves cooling temperatures. Sow seeds in late August or early September. You’ll harvest until the first hard freeze. Many gardeners get a second, bigger crop this way.

Understanding Washington’s Climate Zones

Washington has two main growing zones. The west side is mild and rainy. The east side is drier and more extreme. Your best time to plant cilantro in washington depends on which side you live on.

Western Washington (USDA zones 8a-8b): Milder winters, cooler summers. Spring planting from late March to mid-April. Fall planting from late August to early September.
Eastern Washington (USDA zones 5b-7a): Colder winters, hotter summers. Spring planting from mid-April to early May. Fall planting from late August to mid-September.
Coastal areas (zones 9a): Very mild. You can plant almost year-round. Avoid July and August.

Why Timing Matters So Much

Cilantro is a cool-season annual. It grows leaves best when temperatures are between 50°F and 75°F. When the soil warms above 80°F, the plant thinks it’s time to reproduce. It sends up a flower stalk—this is called bolting. The leaves turn bitter and tough.

In Washington, summer heat arrives suddenly in late June. If you plant in May, you might only get six weeks of harvest. Plant in March or April, and you get ten to twelve weeks. That’s a huge difference.

Fall planting avoids heat entirely. The days shorten, temperatures drop, and cilantro grows slowly but steadily. You can harvest until November in many parts of the state.

Checking Your Soil Temperature

Don’t rely solely on the calendar. Use a soil thermometer. Cilantro seeds germinate best when soil is between 55°F and 68°F. Below 50°F, germination is slow. Above 75°F, it drops off sharply.

Buy a simple soil thermometer at any garden center.
Insert it two inches deep into the soil.
Take readings in the morning for three days.
Plant when the average is above 55°F.

In western Washington, soil reaches 55°F by late March. In eastern Washington, it’s usually mid-April. If you don’t have a thermometer, watch for local signs—when dandelions bloom and soil crumbles easily, it’s time.

Step-by-Step Planting Guide

Follow these steps for the best results. They work for both spring and fall planting.

1. Choose the Right Location

Cilantro needs full sun in spring and fall. In summer, partial shade helps delay bolting. Pick a spot that gets 4-6 hours of direct sunlight. In western Washington, full sun is fine because it’s rarely scorching.

2. Prepare the Soil

Cilantro likes well-drained, loamy soil. It’s not picky, but it hates wet feet. Add compost or aged manure a week before planting. Work it in to a depth of six inches. Avoid heavy clay soil—it stays cold and wet longer.

3. Sow Seeds Correctly

Cilantro seeds are actually small fruits with two seeds inside. Soak them in water for 24 hours before planting. This speeds up germination.

Plant seeds 1/4 inch deep.
Space seeds 2 inches apart in rows 12 inches apart.
Cover lightly with soil.
Water gently with a fine spray.

Seeds germinate in 7-14 days. Keep the soil moist but not soggy. In Washington’s spring rain, you may not need to water at all.

4. Thin Seedlings

When seedlings have two sets of true leaves, thin them to 6 inches apart. This gives each plant room to grow. Crowded plants bolt faster. Use scissors to snip extras at soil level—don’t pull them up, or you’ll disturb roots.

5. Mulch and Water

Apply a thin layer of straw or shredded leaves around plants. This keeps soil cool and moist. Water deeply once a week if rain is scarce. In western Washington, you rarely need to water in spring. In eastern Washington, check soil moisture every few days.

Succession Planting For Continuous Harvest

Don’t plant all your seeds at once. Sow a new row every two weeks. This gives you a steady supply of fresh leaves. Start in late March and continue until early May. Then stop for summer. Resume in late August.

For fall, sow every two weeks from late August through mid-September. Your last planting should be about six weeks before the first expected frost. In western Washington, that’s mid-October. In eastern Washington, it’s late September.

Dealing With Bolting

Even with perfect timing, cilantro will eventually bolt. Here’s how to slow it down.

Provide afternoon shade. Use shade cloth or plant near taller crops.
Keep soil consistently moist. Stress triggers bolting.
Harvest leaves frequently. This delays flowering.
Pinch off flower buds as soon as they appear.

Once flowers open, leaves turn bitter. Let a few plants go to seed. You’ll get coriander seeds for cooking and free plants next year.

Harvesting Tips

Start harvesting when plants are 6 inches tall. Cut outer leaves at the base. Leave the inner rosette to keep growing. Never cut more than one-third of the plant at once.

In spring, you can harvest every 7-10 days. In fall, every 10-14 days. Use fresh leaves immediately. They lose flavor quickly. Store extras in a glass of water in the fridge, like cut flowers.

Common Mistakes To Avoid

Even experienced gardeners mess up cilantro timing. Here are the biggest pitfalls.

Planting too early: Seeds rot in cold, wet soil. Wait until soil hits 55°F.
Planting too late: May planting often fails. Heat arrives before plants mature.
Overwatering: Cilantro likes moisture, not swamp. Let soil dry slightly between waterings.
Skipping fall planting: Fall gives you the best quality leaves. Don’t miss it.
Ignoring microclimates: Your backyard may be warmer or cooler than the general zone. Observe your own garden.

Regional Variations Within Washington

Washington is not uniform. Here are specific tips for major areas.

Seattle and Puget Sound

Mild, wet springs. Plant in late March. Use raised beds for better drainage. Fall planting works until early October. Cilantro often overwinters in mild winters.

Spokane and Eastern Washington

Cold springs, hot summers. Plant in mid-April. Use row covers to protect from late frost. Fall planting must be done by mid-September. First frost hits early.

Olympic Peninsula

Very rainy. Plant in early April. Use well-drained soil or containers. Cilantro loves the cool, damp conditions. Fall planting can extend into November.

Columbia River Gorge

Windy and variable. Plant in mid-April. Protect seedlings with windbreaks. Fall planting is tricky—cold winds arrive fast. Use a cold frame.

Growing Cilantro In Containers

Containers give you more control. You can move them to shade when heat hits. Use pots at least 8 inches deep. Fill with quality potting mix.

Plant seeds 1/4 inch deep, 2 inches apart. Thin to 4 inches apart. Water when the top inch of soil feels dry. In Washington’s rain, check pots daily—they dry out faster than ground.

Container cilantro bolts faster than ground-grown. But you can extend the season by moving pots to a cool, shaded spot in summer. Bring them indoors near a sunny window for winter harvests.

Extending The Season

Want cilantro in July? It’s possible with effort. Use these methods.

Shade cloth: 40-50% shade cloth reduces heat stress.
Cold frame: Keeps soil cool in summer. Open the lid on hot days.
Succession planting indoors: Grow cilantro in pots on a north-facing windowsill.
Hydroponics: Indoor systems give you year-round cilantro.

Most Washington gardeners find it easier to take a break in July and August. The quality drops anyway. Focus on spring and fall harvests.

Seed Saving For Next Year

Let a few plants bolt and flower. After flowers fade, green seeds form. Wait until they turn brown. Cut the seed heads and place them in a paper bag. Shake to release seeds.

Store seeds in a cool, dark place. They stay viable for 2-3 years. Plant them next season. You’ll save money and get plants adapted to your local conditions.

Companion Planting With Cilantro

Cilantro benefits many garden plants. It attracts beneficial insects like ladybugs and lacewings. It repels aphids and spider mites.

Plant near tomatoes, peppers, and eggplants. Cilantro attracts pollinators.
Avoid planting near fennel. They compete for nutrients.
Good neighbors: lettuce, spinach, carrots, and onions.

In Washington’s small gardens, interplant cilantro with slower-growing crops. It’s ready to harvest before they need the space.

Pests And Diseases In Washington

Cilantro has few problems in Washington. The cool, wet climate can cause issues.

Aphids: Spray with water or use insecticidal soap.
Slugs and snails: Common in western Washington. Use beer traps or diatomaceous earth.
Powdery mildew: Rare in spring. Appears in humid fall weather. Improve air circulation.
Root rot: Caused by overwatering. Plant in well-drained soil.

Most problems are minor. Healthy plants outgrow pests. Don’t use harsh chemicals on cilantro—you eat the leaves.

Frequently Asked Questions

Can I plant cilantro in Washington in June?

It’s risky. June planting often fails because heat arrives soon after. You might get a few weeks of harvest before bolting. Better to wait for fall.

What is the latest I can plant cilantro in Washington?

For fall, plant no later than six weeks before the first frost. In western Washington, that’s early October. In eastern Washington, mid-September.

Does cilantro grow back every year in Washington?

No, cilantro is an annual. It dies after flowering. But it self-seeds readily. Let some plants go to seed, and you’ll get volunteers next spring.

Should I start cilantro indoors in Washington?

It’s not necessary. Cilantro hates transplanting. Direct sowing is better. If you must start indoors, use biodegradable pots and transplant carefully when soil is warm.

How do I keep cilantro from bolting in Washington’s summer?

Plant in spring or fall. Provide shade, keep soil moist, and harvest often. Once bolting starts, you can’t reverse it. Pull the plant and use the leaves immediately.

Final Thoughts On Timing

The best time to plant cilantro in washington is a moving target. It depends on your location, the weather, and your willingness to adapt. Start with the general windows: late March to early May for spring, late August to mid-September for fall.

Watch your soil temperature. Observe your plants. Adjust next year based on what you learn. Cilantro is forgiving—even a late planting gives you some harvest. But with the right timing, you’ll have enough for salsa, curries, and garnishes all season long.

Washington’s climate is perfect for cilantro if you work with it, not against it. Embrace the cool, wet springs. Use the mild falls. Skip the hot summer months. Your taste buds will thank you.

Now go plant those seeds. The clock is ticking.