How to Grow Watermelon in a Cold Climate

How to plant out melons in cold climates

Choosing the Right Variety

Selecting the appropriate watermelon variety is crucial when growing in colder climates. Look for early-maturing, cold-hardy cultivars that can thrive in cooler conditions and produce fruit before the first frost. Here are some recommended varieties to consider:

VarietyDays to MaturityCold ToleranceFruit Size

Sugar Baby	70-85 days	Good	6-12 lbs
Blacktail Mountain	70-80 days	Excellent	5-12 lbs
Golden Midget	70-75 days	Good	5-10 lbs
Yellow Doll	75-80 days	Good	6-10 lbs
Early Moonbeam	75-85 days	Good	15-20 lbs

Early-Maturing Varieties

Early-maturing watermelon varieties are well-suited for cold climates because they have a shorter growing period, allowing them to produce fruit before the onset of cool fall temperatures. These varieties are typically smaller in size but can still provide a satisfying harvest.

Disease-Resistant Varieties

In addition to cold tolerance, choosing disease-resistant watermelon varieties can be beneficial in colder regions. Cool, damp conditions can promote the development of fungal diseases like powdery mildew and anthracnose, which can severely impact plant health and fruit production.

Preparing the Growing Site

Proper site selection and preparation are essential for creating an optimal growing environment for watermelons in cold climates.

To maximize sun exposure and warmth, choose a location that receives at least six to eight hours of direct sunlight per day and is protected from cold winds. Well-drained soil is also crucial, as watermelons are susceptible to root rot in overly wet conditions.

Choosing the Right Location

When selecting a planting site for watermelons in cold climates, consider the following factors:

• Sunlight Exposure: Watermelons require full sun exposure, with a minimum of six to eight hours of direct sunlight per day.
• Wind Protection: Look for a spot that is sheltered from cold winds, which can slow plant growth and cause damage.
• Soil Drainage: Watermelons prefer well-drained soil to prevent root rot and other moisture-related issues.

Soil Preparation and Amendments

Proper soil preparation is key to ensuring your watermelons have the necessary nutrients and warmth to thrive. Before planting, amend the soil with organic matter like compost or aged manure to improve fertility and drainage. Raised beds or mounds can also help warm the soil and improve drainage.

Using Row Covers or Cold Frames

To create a warm microclimate and extend the growing season, consider using row covers, cold frames, or low tunnels over your watermelon plants. These structures trap heat and protect the plants from cool temperatures, frost, and wind.

Planting and Care

Once you’ve selected the right variety and prepared the growing site, it’s time to plant and care for your watermelon plants.

Watermelons can be started indoors from seed and transplanted outside after the danger of frost has passed, or they can be direct-sown in the garden when soil temperatures reach at least 70°F (21°C). Proper spacing, watering, and ongoing care are essential for a successful harvest.

Planting Timing and Techniques

In cold climates, it’s best to start watermelon seeds indoors four to six weeks before the last expected frost date. This head start allows the plants to establish a strong root system and reach a larger size before being transplanted outdoors.

When transplanting watermelon seedlings, be sure to harden them off by gradually exposing them to outdoor conditions over a period of 7-10 days. This process helps the plants adjust to the cooler temperatures and wind before being planted in the garden.

If direct-sowing seeds in the garden, wait until the soil temperature has reached at least 70°F (21°C) and the risk of frost has passed. Plant seeds 1-2 inches deep and space them 2-3 feet apart in rows or hills.

Watering and Fertilizing

Consistent moisture is crucial for watermelon growth and fruit development. Water the plants deeply, ensuring the soil stays moist but not waterlogged. Applying a thick layer of mulch around the plants can help retain moisture and suppress weeds.

When it comes to fertilization, watermelons benefit from a balanced fertilizer or compost tea applied every 2-4 weeks during the growing season. Avoid over-fertilizing with nitrogen, as this can promote excessive foliage growth at the expense of fruit production.

Pest and Disease Management

In cold climates, watermelons can be susceptible to various pests and diseases, including:

• Aphids
• Cucumber beetles
• Squash bugs
• Powdery mildew
• Anthracnose
• Fusarium wilt

To prevent and manage these issues, implement the following practices:

• Rotate crop locations annually to disrupt pest and disease cycles.
• Use row covers or insect netting to exclude pests.
• Practice good garden hygiene by removing and destroying infected plant material.
• Apply organic fungicides or copper-based products to control fungal diseases.
• Encourage beneficial insects like ladybugs and lacewings to help control pests naturally.

Harvesting and Storage

As your watermelons approach maturity, it’s essential to know when to harvest and how to properly store them for maximum freshness and flavor.

The key to a successful watermelon harvest lies in recognizing the signs of ripeness, using the right harvesting techniques, and storing the fruits correctly to extend their shelf life.

Ripeness Indicators

Several visual and tactile cues can help you determine when a watermelon is ripe and ready for harvesting:

• The underside of the melon, where it rests on the ground, should have a creamy or yellow spot.
• The rind should have a dull, matte appearance rather than a shiny, glossy look.
• The curly tendril closest to the melon should be dried and brown.
• The melon should feel heavy for its size and produce a dull, hollow sound when tapped.

Harvesting Techniques

When harvesting watermelons, follow these guidelines to ensure the fruits are not damaged:

1. Use a sharp knife or pruning shears to cut the stem about 2-3 inches from the melon.
2. Avoid pulling or twisting the melon off the vine, as this can cause bruising or damage to the fruit.
3. Handle the watermelons gently and avoid stacking or piling them on top of each other.

Storage and Shelf Life

Proper storage is essential for extending the shelf life of your watermelons. Here are some tips:

• Store watermelons at room temperature, out of direct sunlight, for up to two weeks.
• Once cut, refrigerate the watermelon and consume within 3-5 days for optimal flavor and texture.
• Avoid storing whole watermelons in the refrigerator, as this can cause them to develop an off-flavor and mealy texture.

Conclusion

Growing watermelons in cold climates may seem daunting, but with the right strategies and techniques, you can enjoy a bountiful harvest of sweet, juicy fruits. By selecting cold-hardy, early-maturing varieties, preparing the growing site properly, and providing the necessary care and protection, you can successfully cultivate watermelons in cooler regions.

Remember to choose a suitable planting location, amend the soil for optimal drainage and warmth, and use row covers or cold frames to extend the growing season. With diligent watering, fertilization, and pest and disease management, your watermelon plants will thrive.

Finally, pay close attention to the signs of ripeness, harvest your watermelons at the perfect time, and store them correctly to maximize their freshness and flavor. With patience and dedication, you can savor the delicious taste of homegrown watermelons, even in a cold climate.