How to Grow Watermelon in Seattle

Grow 200 LBS of Watermelon On ONE PLANT! [Complete Guide]

Choosing the Right Watermelon Variety

Not all watermelon varieties are created equal when it comes to thriving in Seattle’s cooler temperatures and shorter growing season. To increase your chances of success, it’s crucial to select varieties specifically bred for cool climates and early maturity.

Here’s a table comparing some popular watermelon varieties and their suitability for growing in Seattle:

VarietyDays to MaturityCold ToleranceDisease ResistanceNotes

Sugar Baby	75-85 days	Good	Fusarium Wilt, Anthracnose	Small, icebox-sized melons
Early Moonbeam	75-85 days	Excellent	Fusarium Wilt, Anthracnose	Produces 10-15 lb melons
Crimson Sweet	85-95 days	Moderate	Fusarium Wilt, Anthracnose	Large, oblong melons up to 25 lbs
Northern Lights	80-90 days	Excellent	Fusarium Wilt, Anthracnose	Compact vines, 8-10 lb melons

Heat-Tolerant Varieties

In Seattle’s cool climate, it’s essential to choose heat-tolerant watermelon varieties that can set fruit even when temperatures are relatively low. Look for varieties labeled as “early,” “cold-hardy,” or “short-season.” Examples of heat-tolerant varieties well-suited for Seattle include Sugar Baby, Early Moonbeam, and Northern Lights.

Disease-Resistant Varieties

Diseases like fusarium wilt and anthracnose can quickly destroy watermelon plants, making disease resistance a crucial factor when selecting varieties for Seattle. Many modern watermelon varieties have been bred for resistance to common diseases, such as those listed in the table above.

Preparing the Soil and Planting

Proper soil preparation and planting techniques are essential for giving your watermelon plants the best start possible.

Watermelons thrive in well-draining, nutrient-rich soil with a slightly acidic pH between 6.0 and 6.8. Amend your soil with compost or well-rotted manure to improve fertility and drainage before planting.

Soil Requirements

• pH: 6.0 to 6.8 (slightly acidic)
• Fertility: High levels of organic matter and balanced nutrients
• Drainage: Well-draining soil is crucial to prevent waterlogged conditions

Planting Techniques

1. Start seeds indoors 4-6 weeks before the last expected frost date.
2. Transplant seedlings or direct sow seeds after the soil has warmed to at least 70°F (21°C).
3. Space plants 2-3 feet apart in rows 6-8 feet apart, or plant in hills spaced 6-8 feet apart.
4. Plant seeds 1 inch deep and keep the soil consistently moist until germination.
5. Use row covers or cold frames to warm the soil and protect young plants from cool temperatures.

Caring for Watermelon Plants

Even after planting, watermelon plants require attentive care throughout the growing season to thrive in Seattle’s climate.

Consistent watering, fertilizing, and pest/disease management are essential for promoting healthy growth and ensuring a bountiful harvest.

Watering Needs

• Water deeply and consistently, providing 1-2 inches of water per week (more during hot, dry periods).
• Avoid getting leaves wet, which can promote fungal diseases.
• Mulch around plants to conserve soil moisture.

Fertilizing

• Incorporate compost or well-rotted manure into the soil before planting.
• Side-dress plants with a balanced, organic fertilizer (e.g., 10-10-10) when vines begin to run.
• Avoid over-fertilizing, which can promote excessive foliage growth at the expense of fruit production.

Pest and Disease Management

Common pests and diseases that can affect watermelons in Seattle include:

• Pests: Aphids, cucumber beetles, squash bugs, and squash vine borers.
• Diseases: Powdery mildew, downy mildew, anthracnose, and fusarium wilt.

To prevent and manage these issues:

• Practice crop rotation and remove plant debris from the garden.
• Use floating row covers to exclude pests.
• Apply organic fungicides or insecticidal soaps as needed.
• Choose disease-resistant varieties.

Harvesting and Storing Watermelons

Knowing when to harvest and how to properly store watermelons is crucial for enjoying their peak flavor and extending their shelf life.

Signs of Ripeness

Look for these indicators that a watermelon is ripe and ready for harvesting:

• The underside (where it rests on the ground) develops a creamy or yellow color.
• The curly tendril nearest the fruit turns brown and dries up.
• The rind takes on a dull, matte appearance rather than a glossy shine.
• The watermelon feels heavy for its size.
• It produces a hollow sound when tapped.

Harvesting Techniques

1. Use a sharp knife or pruners to cut the watermelon from the vine, leaving 2-3 inches of stem attached.
2. Avoid pulling or twisting the watermelon, as this can damage the vine.
3. Handle watermelons carefully to prevent bruising or cracking.
4. Cut off the remaining stem after harvesting.

Storage and Preservation

• Store whole watermelons at room temperature for up to 2 weeks.
• Refrigerate cut watermelon in an airtight container for up to 5 days.
• Freeze cut watermelon for longer-term storage (up to 1 year).
• Can or pickle watermelon rind for preservation.

Conclusion

With the right varieties, soil preparation, and care, it’s entirely possible to grow delicious watermelons even in Seattle’s cool climate. By following these tips and techniques, you’ll be well on your way to enjoying the sweet, juicy rewards of your hard work in the garden. So, don’t be deterred by Seattle’s weather – embrace the challenge and savor the taste of homegrown watermelons!