when to plant tomatoes seattle

When to Plant Tomatoes in Seattle

Planting tomato seedlings in Seattle usually occurs from late May to early June. This timing is crucial because it allows the soil to warm sufficiently, reducing the risk of frost damage which can be detrimental to tomato growth.

Understanding Seattle’s Climate and Tomato Planting

Seattle’s maritime climate presents unique challenges for growing heat-loving plants like tomatoes. The relatively short growing season and cool temperatures mean timing is everything. Planting too early can expose seedlings to frost, while planting too late might limit the plant’s ability to produce a substantial harvest.

The Last Frost Date

The typical last frost date in the Seattle area is around mid-May. While it varies from year to year, waiting until after this date significantly reduces the risk of losing your tomato plants to frost. Checking local weather forecasts and consulting with experienced gardeners can provide further guidance.

Soil Temperature

Tomatoes thrive in warm soil. Ideally, the soil temperature should be at least 60°F (15°C) before planting. Using a soil thermometer can help you determine when the soil is warm enough. You can also warm the soil in advance by covering it with black plastic sheeting for a few weeks prior to planting.

Starting Tomatoes Indoors

Because of Seattle’s short growing season, starting tomato plants indoors 6-8 weeks before the last frost date is highly recommended. This gives the plants a head start and ensures a better chance of a bountiful harvest. Purchase seedlings from a reputable nursery or start your own from seeds.

Hardening Off Seedlings

Before transplanting your tomato seedlings outdoors, it’s essential to “harden them off.” This process involves gradually exposing the plants to outdoor conditions (sun, wind, and cooler temperatures) over a period of one to two weeks. This helps them acclimate and reduces transplant shock. Learn more about tomatoes on Wikipedia.

Choosing the Right Tomato Variety

Select tomato varieties that are well-suited for Seattle’s climate. Look for varieties described as “early” or “cool-weather” tolerant. These will mature more quickly and are more likely to produce a good crop before the end of the growing season.

Frequently Asked Questions

What happens if I plant tomatoes too early in Seattle?

Planting tomatoes too early can expose them to frost, which can damage or kill the plants. Cool soil temperatures can also stunt their growth.

Can I plant tomatoes in containers in Seattle?

Yes, planting tomatoes in containers is a great option for Seattle, especially if you have limited space. Use large containers (at least 15 gallons) and choose varieties that are suitable for container growing.

How do I protect my tomato plants from frost in Seattle?

If a late frost is predicted, cover your tomato plants with blankets, sheets, or plastic tarps. You can also use frost blankets or cloches. Remove the coverings once the threat of frost has passed.

What kind of soil is best for growing tomatoes in Seattle?

Tomatoes prefer well-drained soil that is rich in organic matter. Amend your soil with compost or other organic materials before planting. Raised beds can also improve drainage.

How much sun do tomatoes need in Seattle?

Tomatoes need at least 6-8 hours of sunlight per day. Choose a sunny location in your garden for best results.

Summary

Successful tomato growing in Seattle hinges on proper timing. Aim to plant your tomato seedlings from late May to early June, after the last frost date and when the soil has warmed sufficiently. Starting seeds indoors, hardening off seedlings, and selecting appropriate varieties are essential steps for a bountiful harvest.