How to Grow the Biggest Watermelon

Growing Giant Watermelons with Todd Dawson and Soil3

Selecting the Right Watermelon Variety

The first step in growing gigantic watermelons is choosing the right variety. Not all watermelon cultivars are created equal when it comes to size potential. Some varieties are bred specifically for their ability to produce massive fruits, while others prioritize factors like disease resistance or flavor.

When selecting a watermelon variety for size, look for cultivars labeled as "giant," "colossal," or "mammoth." These varieties are genetically predisposed to grow larger than standard watermelon types.

Here's a table comparing some popular large watermelon varieties and their key characteristics:

VarietyDays to MaturityAverage WeightNoteworthy Traits

Carolina Cross	90-100 days	200+ lbs	Oblong shape,striped rind
Carolina Cross 183	90-100 days	200+ lbs	Improved disease resistance
Million Bucks	90-95 days	150-200 lbs	Bright red flesh, high yield
Crimson Tide	95-100 days	150-200 lbs	Crisp texture, high sugar content
Cream of Saskatchewan	100-120 days	150-200 lbs	White rind, yellow flesh

Additionally, consider your growing region and choose varieties suited to your local climate and growing season length.

Introductory sentences: While variety selection is crucial, growing massive watermelons also depends on other factors like soil preparation, fertilization, and cultural practices. Let's explore these in detail.

Open-Pollinated vs. Hybrid Varieties

When selecting a watermelon variety, you'll encounter two main types: open-pollinated and hybrid. Open-pollinated varieties are stabilized cultivars that can produce seeds genetically identical to the parent plant. Hybrid varieties, on the other hand, are created by cross-pollinating two distinct parent lines, resulting in more uniform and vigorous plants.

While both types can produce large watermelons, hybrid varieties tend to have a size advantage due to their genetic vigor and carefully selected traits. However, open-pollinated varieties are often preferred by home gardeners for their ability to save seeds from year to year.

Days to Maturity

Another critical factor to consider when choosing a watermelon variety is the number of days to maturity. This refers to the approximate time it takes for a watermelon to reach full ripeness from the day it's planted.

Larger watermelon varieties generally require a longer growing season, with many taking 90 days or more to mature fully. If you live in an area with a shorter growing season, you may need to select an early-maturing variety or start your plants indoors to ensure they have enough time to reach their full potential size.

Preparing the Soil for Maximum Growth

Proper soil preparation is essential for growing massive watermelons. These plants have extensive root systems and high nutrient demands, so ensuring your soil is rich and well-draining is crucial.

Introductory sentences: Before planting, it's essential to test your soil and make any necessary amendments to create the ideal growing environment for your watermelons. Let's explore some key soil preparation techniques.

Soil Amendments

To provide the optimal growing conditions for your watermelons, consider adding the following soil amendments:

• Compost or well-rotted manure: Improves soil structure, water retention, and nutrient availability.
• Aged bark or leaf mold: Increases soil aeration and drainage.
• Balanced fertilizer: Provides essential nutrients for plant growth. Look for a balanced NPK (nitrogen, phosphorus, potassium) ratio.
• Agricultural lime or sulfur: Adjusts soil pH to the ideal range of 6.0 to 6.8 for watermelons.
• Micronutrient supplements: Supplies essential trace elements like boron, zinc, and iron.

Raised Beds or Hills

Watermelons thrive in well-drained soil conditions, which can be challenging in heavy clay or poorly drained areas. In these situations, consider planting your watermelons in raised beds or hills.

Raised beds provide improved drainage and soil aeration, allowing the roots to spread more easily. To create a raised bed, mound soil into a rectangular or circular shape, typically 6 to 12 inches high and 3 to 4 feet wide.

Alternatively, you can plant watermelons on hills, which are raised mounds of soil about 12 inches high and 2 to 3 feet wide. Hills help warm the soil faster in the spring and improve drainage, essential for early growth and fruit development.

Planting and Spacing

Proper planting and spacing are crucial for maximizing watermelon size and yield. Overcrowding can lead to stunted growth, while excessive spacing can result in wasted space and reduced yields.

Introductory sentences: Whether you're starting from seeds or transplants, following the correct planting techniques will give your watermelons the best start and allow ample room for vines to spread.

Seed Starting

If you live in an area with a shorter growing season or want to get a head start, you can start your watermelon seeds indoors 4 to 6 weeks before your last expected frost date. Use a seed-starting mix or potting soil and plant the seeds 1 inch deep in individual containers or trays.

Keep the soil consistently moist but not waterlogged, and provide bottom heat if possible to encourage germination. Once the seedlings have developed their first true leaves, gradually expose them to cooler temperatures and direct sunlight to harden them off before transplanting outdoors.

Direct Sowing

In regions with long, warm growing seasons, you can sow watermelon seeds directly in the ground. Wait until the soil has warmed to at least 70°F (21°C) and all danger of frost has passed.

Plant the seeds 1 inch deep and 18 to 24 inches apart in rows or hills, spacing the rows 6 to 8 feet apart. This spacing allows ample room for the vines to spread and reduces competition for nutrients and water.

Watering and Fertilizing for Optimal Growth

Proper watering and fertilization are essential for encouraging maximum watermelon size and vigor. These plants have high water and nutrient demands, especially during fruit development.

Introductory sentences: Maintaining consistent soil moisture and providing the right nutrients at the right times can make a significant difference in the size and quality of your watermelon crop.

Watering Techniques

Watermelons require consistent soil moisture throughout their growing cycle, but they don't tolerate waterlogged conditions. Consider implementing one of these watering techniques:

• Drip irrigation: This method delivers water directly to the root zone, reducing water waste and minimizing disease risk from wet foliage.
• Furrow irrigation: Create small trenches or furrows between plant rows and allow water to flow down these channels, gradually seeping into the soil.
• Soaker hoses: Lay porous soaker hoses along the plant rows to deliver water directly to the root zone, minimizing evaporation and runoff.

Aim to provide 1 to 2 inches of water per week, adjusting as needed based on weather conditions and soil drainage.

Fertilizer Schedule

Watermelons are heavy feeders, and proper fertilization is essential for promoting maximum growth and fruit size. Here's a recommended fertilizer schedule:

1. At planting: Incorporate a balanced fertilizer, such as 10-10-10 or a similar NPK ratio, into the soil at the rate of 1 pound per 100 square feet.
2. Four weeks after planting: Apply a high-nitrogen fertilizer, such as ammonium nitrate or blood meal, at the rate of 1/2 pound per 100 square feet.
3. Flowering stage: Switch to a high-phosphorus fertilizer, like bone meal or rock phosphate, at the rate of 1 pound per 100 square feet to promote fruit set and development.
4. Fruit development: Continue applying a high-phosphorus fertilizer every 2 to 3 weeks until the watermelons reach their desired size.

Always follow the specific application rates on the fertilizer labels and water deeply after applying to prevent root burn.

Vine Training and Pollination

Proper vine training and pollination are crucial for maximizing watermelon size and yield. These vining plants can quickly become unruly without proper support, and inadequate pollination can result in poor fruit set or lopsided melons.