How to Grow Watermelon in Minnesota

How To Grow Melons Harvest Time, Melon Minnesota Midget, Vegetable Gardening

Choosing the Right Watermelon Variety

Selecting the appropriate watermelon variety is crucial for successful cultivation in Minnesota's climate. Opting for cold-hardy and early-maturing varieties can make a significant difference in your watermelon growing experience. Here's a table comparing some popular watermelon varieties suitable for Minnesota:

VarietyDays to MaturityCold HardinessDisease ResistanceFruit Size

Sugar Baby	75-85 days	Good	Fusarium Wilt, Anthracnose	6-10 lbs
Blacktail Mountain	70-80 days	Excellent	Fusarium Wilt, Anthracnose	8-12 lbs
Yellow Doll	70-75 days	Good	Fusarium Wilt, Anthracnose	5-8 lbs
Crimson Sweet	85-90 days	Moderate	Fusarium Wilt, Anthracnose	20-25 lbs

As you can see, varieties like Sugar Baby, Blacktail Mountain, and Yellow Doll are excellent choices for Minnesota's climate, combining early maturity, cold hardiness, and disease resistance. Crimson Sweet, while a popular variety, may require a longer growing season and warmer temperatures to reach its full potential.

Cold-Hardy Watermelon Varieties

Cold-hardy watermelon varieties are specifically bred to withstand cooler temperatures and thrive in regions with shorter growing seasons. These varieties are well-suited for Minnesota's climate and can be planted earlier in the season, increasing their chances of reaching maturity before the first frost. Some excellent cold-hardy options include Blacktail Mountain, Sweetie Pie, and Northern Xposed.

Early-Maturing Watermelon Varieties

Early-maturing watermelon varieties are another excellent choice for Minnesota gardeners. These varieties have a shorter time to maturity, typically ranging from 70 to 85 days, allowing them to produce ripe fruits before the onset of cooler temperatures in fall. Some popular early-maturing varieties include Sugar Baby, Yellow Doll, and Harvest Moon.

Preparing the Soil and Site Selection

Proper soil preparation and site selection are crucial for successful watermelon cultivation in Minnesota. Watermelons thrive in well-draining, nutrient-rich soil and require ample sunlight exposure.

Watermelons prefer slightly acidic soil with a pH range of 6.0 to 6.8. Before planting, it's essential to test your soil and amend it accordingly. Incorporating compost or well-rotted manure can improve soil structure and provide essential nutrients for your watermelon plants.

Soil Preparation

To prepare your soil for watermelon cultivation, follow these steps:

1. Test your soil's pH level and adjust it to the desired range if necessary.
2. Remove any weeds, rocks, or debris from the planting area.
3. Spread a 2-4 inch layer of well-rotted compost or manure over the planting area and till it into the soil to a depth of 8-12 inches.
4. Create raised beds or hills spaced 6-8 feet apart to improve drainage and provide a warmer soil environment for watermelon plants.
5. Consider using black plastic mulch or organic mulch to help warm the soil and suppress weeds.

Site Selection

When choosing a site for your watermelon patch, consider the following factors:

• Sunlight exposure: Watermelons require at least 6-8 hours of direct sunlight per day. Select a site with full sun exposure and minimal shade.
• Wind protection: Strong winds can damage watermelon vines and promote soil drying. Choose a site with natural windbreaks or consider installing a windbreak structure.
• Water source proximity: Watermelons have high water requirements, so it's essential to have a nearby water source for easy irrigation.
• Soil drainage: Watermelons thrive in well-draining soils. Avoid low-lying areas prone to waterlogging, as this can lead to root rot and other issues.

Planting and Caring for Watermelon Plants

Proper planting techniques and ongoing care are essential for ensuring healthy watermelon plant growth and fruit production. Follow these guidelines for successful watermelon cultivation in Minnesota:

Watermelons are warm-season crops and should be planted after the last frost date in your area, typically around late May or early June in Minnesota. Proper planting depth, spacing, and timing are crucial for optimal growth and yield.

Planting Watermelon Seeds

Here are the steps for planting watermelon seeds:

1. Planting depth: Sow watermelon seeds 1-2 inches deep in the prepared hills or raised beds.
2. Spacing: Plant 2-3 seeds per hill, spaced 6-8 feet apart in rows, or 8-10 feet apart in both directions if planting in a hill system.
3. Timing: Plant seeds after the last expected frost date in your area, typically around late May or early June in Minnesota.
4. Row covers or black plastic mulch: Consider using row covers or black plastic mulch to warm the soil and protect young plants from pests and cool temperatures.

After seedlings emerge, thin them out to the strongest one or two plants per hill or spacing.

Watering and Fertilizing

Watermelons have high water requirements, especially during fruit development. Here are some watering and fertilizing guidelines:

• Watering: Water plants deeply, providing about 1-2 inches of water per week, depending on weather conditions. Avoid wetting the vines and leaves to prevent fungal diseases.
• Fertilizing: Apply a balanced fertilizer, such as 10-10-10, at the time of planting and again when vines begin to run. Side-dress with additional nitrogen fertilizer when fruits start developing.

Pest and Disease Management

Watermelons are susceptible to various pests and diseases in Minnesota, including:

• Pests: Cucumber beetles, aphids, and squash bugs can all damage watermelon plants. Use row covers, insecticidal soaps, or organic pesticides to control infestations.
• Diseases: Fungal diseases like powdery mildew, anthracnose, and fusarium wilt can affect watermelon plants. Choose disease-resistant varieties, practice crop rotation, and use fungicides if necessary.

Regular monitoring and prompt action are essential for effective pest and disease management.

Harvesting and Storing Watermelons

Knowing when to harvest and how to properly store watermelons is crucial for enjoying the fruits of your labor.

Watermelons are typically ready to harvest 80-100 days after planting, depending on the variety. Here are some signs to look for:

Signs of Ripeness

• Tendril drying: The tendril closest to the fruit will turn brown and dry when the watermelon is ripe.
• Bottom color: The bottom of the watermelon, where it rests on the ground, will turn from white to creamy yellow or buttery color when ripe.
• Hollow sound: Gently tap the watermelon with your knuckles. A dull, hollow sound indicates ripeness.
• Resistance to pressure: A ripe watermelon will have a slight give when you press the skin with your thumb but should not be overly soft.

Harvesting Techniques

1. Use a sharp knife or pruning shears to cut the watermelon from the vine, leaving about 2-3 inches of stem attached.
2. Handle watermelons carefully to avoid bruising or damaging the fruit.
3. Consider using a garden cart or wagon to transport watermelons from the garden to prevent injury from carrying heavy fruits.

Storage Tips

Proper storage can extend the shelf life of your freshly harvested watermelons:

• Store watermelons at room temperature, away from direct sunlight, for up to 2 weeks.
• Once cut, refrigerate watermelon slices in an airtight container for up to 5 days.
• Avoid storing watermelons near ethylene-producing fruits like apples or bananas, as this can accelerate ripening and deterioration.