How to Grow Watermelon in Wyoming

Beginning a vegetable garden with seed in Wyoming

Choose the Right Watermelon Variety

Selecting the appropriate watermelon variety is crucial for successful cultivation in Wyoming’s climate. Different varieties have varying levels of tolerance to heat, cold, and disease resistance. Choosing the right one can mean the difference between a thriving crop and a disappointing yield.

When it comes to watermelon varieties, there are two main factors to consider: heat tolerance and disease resistance. Wyoming’s summers can be hot and dry, while the growing season is relatively short, making heat-tolerant varieties a necessity.

VarietyDays to MaturityHeat ToleranceDisease Resistance

Sugar Baby	75-85	High	Moderate
Crimson Sweet	85-95	High	High
Charleston Gray	90-100	Moderate	High
Mickylee	75-85	High	Moderate
Blacktail Mountain	80-90	High	High

Heat-Tolerant Varieties

Watermelons thrive in warm temperatures, but extreme heat can cause problems like poor fruit set, stunted growth, and sunburn. To combat Wyoming’s hot summers, choose varieties like Sugar Baby, Crimson Sweet, and Mickylee, which have excellent heat tolerance and can produce high-quality fruits even in scorching conditions.

Disease-Resistant Varieties

Fungal and bacterial diseases can quickly devastate a watermelon crop, especially in regions with unpredictable weather patterns like Wyoming. Varieties like Crimson Sweet and Blacktail Mountain offer robust disease resistance, helping protect your crop from common threats like fusarium wilt, anthracnose, and powdery mildew.

Prepare the Soil

Proper soil preparation is essential for watermelon cultivation in Wyoming. These vining plants have extensive root systems and require well-draining, nutrient-rich soil to thrive. Follow these steps to prepare your soil for watermelon cultivation:

• Test your soil’s pH level and nutrient content. Watermelons prefer slightly acidic soil with a pH between 6.0 and 6.8.
• Amend the soil with well-rotted compost or aged manure to improve fertility and drainage.
• Incorporate a balanced fertilizer into the soil, following the recommendations from your soil test report.
• Loosen the soil to a depth of 8-12 inches, breaking up any compacted areas to encourage root growth.
• Create raised beds or hills to improve drainage and warm the soil faster in spring.

Soil Testing and Amendments

Soil testing is crucial for understanding the specific needs of your garden and ensuring your watermelons have access to the necessary nutrients. Contact your local cooperative extension service or a reputable soil testing laboratory to have your soil analyzed. Based on the results, they can provide recommendations for the appropriate amendments to add, such as compost, manure, lime, or fertilizers.

Raised Beds or Hills

In Wyoming’s climate, raised beds or hills can provide several advantages for watermelon cultivation. These elevated planting areas allow the soil to warm up more quickly in spring, extending the growing season. They also improve drainage, preventing waterlogged conditions that can lead to root rot and other problems.

Planting and Care

Once you’ve selected the right variety and prepared the soil, it’s time to plant your watermelons and provide them with the care they need to thrive. Follow these steps for successful planting and care:

1. Start seeds indoors 4-6 weeks before the last expected frost date in your area.
2. Transplant seedlings or direct sow seeds after the last frost, when soil temperatures reach at least 70°F (21°C).
3. Plant seeds 1-2 inches deep and space them 2-3 feet apart in rows 6-8 feet apart.
4. Water deeply and regularly, providing 1-2 inches of water per week, depending on weather conditions.
5. Apply a balanced fertilizer every 4-6 weeks, following the recommended rates on the product label.
6. Mulch around the plants to conserve moisture and suppress weeds.

Planting Depth and Spacing

Proper planting depth and spacing are crucial for watermelon growth and development. Plant seeds or transplants at a depth of 1-2 inches, ensuring adequate soil coverage while allowing for easy emergence. Space plants 2-3 feet apart in rows that are 6-8 feet apart. This spacing allows the vines to spread out and prevents overcrowding, which can lead to disease and reduced yields.

Watering and Fertilizing

Watermelons have high water and nutrient demands, especially during fruit development. Provide 1-2 inches of water per week, adjusting based on weather conditions and soil moisture levels. Avoid overhead watering, as this can promote fungal diseases. Instead, use drip irrigation or soaker hoses to water the plants at the root zone.

Fertilize your watermelon plants every 4-6 weeks with a balanced fertilizer, following the recommended rates on the product label. Alternatively, you can use a slow-release fertilizer at planting time to provide a steady supply of nutrients throughout the growing season.

Mulching and Weed Control

Mulching around your watermelon plants can be tremendously beneficial. A 2-4 inch layer of organic mulch, such as straw, leaves, or bark chips, helps to retain soil moisture, suppress weeds, and regulate soil temperatures. Additionally, it prevents soil from splashing onto the plants, reducing the risk of disease.

Weeds can compete with watermelons for water, nutrients, and sunlight, so effective weed control is essential. In addition to mulching, hand-pulling or cultivating the soil around the plants can help manage weeds. Avoid using herbicides, as they can damage the watermelon vines and potentially leave harmful residues on the fruit.

Pest and Disease Management

Like any crop, watermelons are susceptible to various pests and diseases. Implementing preventive measures and monitoring your plants closely can help you identify and address issues before they become severe. Here are some common pests and diseases to watch out for in Wyoming:

Pest/DiseaseSymptomsManagement Strategies

Cucumber Beetles	Wilting, stunted growth, leaf damage	Row covers, hand-picking, insecticidal soap
Aphids	Curled leaves, stunted growth, honeydew secretion	Insecticidal soap, beneficial insects
Powdery Mildew	White, powdery growth on leaves and stems	Resistant varieties, pruning, fungicides
Fusarium Wilt	Wilting, yellowing, and plant death	Resistant varieties, crop rotation, soil solarization
Anthracnose	Circular lesions on leaves, stems, and fruit	Fungicides, crop rotation, resistant varieties

Insect Pests

Common insect pests that can harm watermelons in Wyoming include cucumber beetles, aphids, and squash bugs. These pests can cause wilting, stunted growth, and leaf damage, ultimately reducing yields and fruit quality.

To control insect pests, implement integrated pest management strategies. Use row covers or insect netting to physically exclude pests, hand-pick and remove any visible insects, and encourage beneficial insects like ladybugs and lacewings. As a last resort, you can use insecticidal soaps or other approved organic pesticides, following label instructions carefully.

Fungal and Bacterial Diseases

Watermelons are susceptible to various fungal and bacterial diseases, including powdery mildew, fusarium wilt, and anthracnose. These diseases can cause leaf spots, wilting, and fruit rot, leading to significant yield losses if left unchecked.

Preventive measures like choosing disease-resistant varieties, practicing crop rotation, and maintaining proper plant spacing and airflow can help reduce the risk of disease. If disease does occur, fungicides approved for use on watermelons may be necessary. Always follow label instructions carefully and consult with your local cooperative extension service for specific recommendations.

Harvesting and Storage

Knowing when to harvest and how to properly handle and store your watermelons is crucial for enjoying the best possible flavor and quality. Here are some tips for successful harvesting and storage:

• Watermelons are typically ready for harvest 80-100 days after planting, depending on the variety.
• Look for a cream or yellow spot on the underside of the melon, indicating maturity.
• Gently twist the melon off the vine, leaving a 2-inch stem attached.