How to Grow Watermelon in Indiana

Don't Plant Watermelon Seeds in the Ground!!!

Growing watermelons in Indiana can be a rewarding experience, providing you with a bountiful harvest of sweet, juicy fruits. However, it requires careful planning and attention to detail. In this comprehensive guide, we'll explore everything you need to know about how to grow watermelon in Indiana, from selecting the right variety to harvesting and storage techniques.

Choosing the Right Watermelon Variety

Selecting the appropriate watermelon variety is crucial for a successful crop in Indiana's climate. Consider factors such as days to maturity, disease resistance, and suitability for your growing region. Here's a table comparing some popular watermelon varieties for Indiana:

VarietyDays to MaturityDisease ResistanceNotes

Sugar Baby	75-85 days	Anthracnose, Fusarium Wilt	Small, icebox type, great for early harvests
Crimson Sweet	85-90 days	Anthracnose, Fusarium Wilt	Large, oblong fruits with deep red flesh
Charleston Gray	90-100 days	Anthracnose, Fusarium Wilt	Large, gray-green rind, sweet red flesh
Millennium	90-100 days	Anthracnose, Fusarium Wilt	High yields, crisp texture, and excellent flavor

Early/Main Season Varieties

For Indiana growers, it's essential to choose varieties that can mature within the state's growing season. Early season varieties like Sugar Baby and main season varieties like Crimson Sweet and Charleston Gray are well-suited for Indiana's climate. These varieties are known for their disease resistance, sweet flavor, and ability to thrive in the region's conditions.

Disease-Resistant Varieties

Watermelons are susceptible to various diseases, and choosing disease-resistant varieties can help ensure a healthy crop. Varieties like Crimson Sweet, Charleston Gray, and Millennium are resistant to common watermelon diseases such as anthracnose and fusarium wilt, which can significantly impact yield and fruit quality.

Site Selection and Soil Preparation

Proper site selection and soil preparation are critical for successful watermelon cultivation in Indiana. Watermelons thrive in well-drained, nutrient-rich soils and require ample sunlight exposure.

Watermelons need a minimum of 6-8 hours of direct sunlight per day, so choose a site that receives full sun exposure. Avoid areas with heavy shade or near large trees or buildings that could block sunlight.

The soil should be loose, well-draining, and rich in organic matter. Conduct a soil test to determine the pH level and nutrient content, and amend the soil accordingly. Watermelons prefer a slightly acidic soil with a pH range of 6.0 to 6.8.

Sunlight Requirements

Watermelons are warm-season crops that require plenty of sunlight to thrive. They need at least 6-8 hours of direct sunlight per day, preferably during the hottest part of the day. Choose a site that receives full sun exposure, with minimal shade from trees, buildings, or other obstructions.

Soil Amendments and Fertility

Watermelons grow best in well-drained, nutrient-rich soils with a slightly acidic pH between 6.0 and 6.8. Before planting, perform a soil test to determine the pH level and nutrient content of your soil. Based on the test results, amend the soil accordingly.

If the soil is too acidic, add limestone or wood ash to raise the pH. If the soil is too alkaline, add sulfur or peat moss to lower the pH. Watermelons are heavy feeders and benefit from the addition of well-rotted compost or aged manure to improve soil fertility and structure.

Planting and Care

Proper planting and care techniques are essential for achieving a bountiful watermelon harvest in Indiana. Follow these steps for optimal results.

Watermelons can be grown from seeds or transplants, and both methods have their advantages and disadvantages. Direct seeding is more cost-effective and avoids transplant shock, while transplanting allows for an earlier start and better control over plant spacing.

Direct Seeding vs. Transplanting

• Direct Seeding: Plant seeds directly in the prepared soil after the last frost date, when soil temperatures reach at least 70°F. This method is more cost-effective and avoids transplant shock, but the growing season may be shorter.
• Transplanting: Start seeds indoors 4-6 weeks before the last frost date, and transplant seedlings into the prepared soil after hardening them off. This method allows for an earlier start and better control over plant spacing but requires more effort and care during the transplanting process.

Spacing and Trellising

Proper spacing and trellising are essential for optimal growth and fruit production. Watermelons require ample space for their vines to spread and should be planted in hills or rows with adequate spacing.

• Hills: Plant 4-6 seeds per hill, spaced 6-8 feet apart in all directions. After germination, thin to the strongest 2-3 plants per hill.
• Rows: Plant seeds 12-18 inches apart in rows spaced 6-8 feet apart.

Trellising can help maximize space and improve air circulation, reducing the risk of disease. Train the vines onto a trellis or use a vertical growing system to support the fruits and prevent them from touching the ground.

Watering and Mulching

Watermelons have high water requirements, especially during fruit development. Ensure consistent soil moisture by providing deep waterings, being careful not to overwater or allow the soil to dry out completely.

Mulching around the plants can help retain soil moisture, suppress weeds, and regulate soil temperature. Use organic mulches like straw, leaves, or grass clippings, spreading them around the plants in a 2-4 inch layer.

Pest and Disease Management

Like any crop, watermelons are susceptible to various pests and diseases that can negatively impact plant health and yield. Implementing preventive measures and monitoring your plants regularly are essential for successful pest and disease management.

Watermelons are attractive to a variety of insect pests, including cucumber beetles, aphids, and squash bugs. These pests can damage plants, transmit diseases, and affect fruit quality. Implementing organic control methods, such as row covers, companion planting, and handpicking, can help manage pest populations.

• Cucumber Beetles: These striped or spotted beetles can transmit bacterial wilt and feed on leaves and stems. Use row covers, handpick, or apply neem oil or pyrethrin-based insecticides.
• Aphids: These small, soft-bodied insects can infest plants and secrete sticky honeydew, attracting sooty mold. Use insecticidal soaps, neem oil, or encourage beneficial insects like ladybugs.
• Squash Bugs: These brown, shield-shaped bugs feed on leaves and stems, causing wilting and plant damage. Handpick, use row covers, or apply insecticidal soap or neem oil.

Common Diseases

Watermelons are susceptible to various fungal, bacterial, and viral diseases that can impact plant health and fruit quality. Implementing preventive measures, such as crop rotation, proper spacing, and avoiding overhead watering, can help minimize disease risk.

• Fusarium Wilt: Caused by a soil-borne fungus, this disease causes wilting, yellowing, and plant death. Choose resistant varieties, practice crop rotation, and avoid over-watering.
• Anthracnose: This fungal disease causes dark, sunken lesions on leaves, stems, and fruits. Apply fungicides, remove infected plant material, and rotate crops.
• Powdery Mildew: A fungal disease that causes a white, powdery growth on leaves, reducing photosynthesis. Use resistant varieties, improve air circulation, and apply fungicides if needed.

Harvesting and Storage

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

Watermelons are typically ready to harvest about 80-100 days after planting, depending on the variety. Look for these ripeness indicators:

• The underside of the melon, where it rests on the ground, will turn from white to creamy or yellow.
• The curly tendril on the vine nearest the fruit will turn brown and dry.
• The rind will become dull and develop a waxy appearance.
• The melon will produce a hollow sound when tapped.