Square watermelons have become a novelty item that captivates people’s attention and sparks curiosity. These uniquely shaped fruits were first developed by Japanese farmers as a space-saving solution for refrigerators. To create square watermelons, growers place young melons into cube-shaped molds, allowing them to develop into perfect squares as they mature.

The process of growing square watermelons requires careful attention and specific techniques. Farmers start by selecting small, developing watermelons and gently placing them inside specially designed square containers. As the fruit grows, it naturally conforms to the shape of the mold, resulting in a striking cubic appearance. This method not only produces an eye-catching product but also serves as an excellent conversation starter at gatherings.

While square watermelons are primarily grown for aesthetic purposes, they have gained popularity beyond Japan. Gardeners and fruit enthusiasts around the world have adopted this technique, eager to experiment with unconventional fruit shaping. The unique appearance of these melons makes them a sought-after item for those looking to add a touch of whimsy to their dining experiences or impress guests with an unusual centerpiece.

Understanding Square Watermelons

Square watermelons are a unique agricultural innovation that combines form and function. These eye-catching fruits have gained popularity for their distinctive shape and practical benefits.

Origin and Popularity

Square watermelons were first developed by Japanese farmers in the 1980s. The idea stemmed from the desire to create a more space-efficient fruit that could fit easily into smaller Japanese refrigerators. These unusually shaped melons quickly caught attention both in Japan and internationally.

Today, square watermelons are grown in several countries. They’re often seen as luxury items or conversation starters at upscale events. Despite their visual appeal, it’s important to note that square watermelons are typically harvested before fully ripe to maintain their shape, making them more decorative than edible.

Benefits of Square Shape

The square shape of these watermelons offers several advantages. Their flat sides allow for easy stacking and storage, reducing shipping costs and damage during transport. This shape also prevents rolling, making them safer to handle and display.

Square watermelons fit neatly into refrigerators, saving valuable space in small kitchens. Their unique appearance makes them popular as gifts or centerpieces. Some people even use them as decorative items in their homes or businesses.

While square watermelons are more expensive than traditional round ones, their novelty and practicality continue to drive interest. They serve as a prime example of how agricultural innovation can create products that are both functional and visually striking.

Preparation for Planting

Proper preparation is crucial for growing square watermelons successfully. Selecting the right seeds and creating optimal soil conditions lay the foundation for healthy plants and shapely fruits.

Selecting Watermelon Seeds

Choose compact or dense-fleshed watermelon varieties for square shaping. Look for seeds labeled as “icebox” or “personal-sized” watermelons, as these tend to be smaller and more suitable for molding. Consider varieties like Sugar Baby or Golden Midget for their manageable size and sweet flavor.

Purchase seeds from reputable suppliers to ensure quality and viability. Fresh seeds have a higher germination rate, so check the packaging date. For a successful harvest, select disease-resistant varieties that suit your local climate.

Soil and Compost

Watermelons thrive in well-draining soil rich in organic matter. Test your soil pH, aiming for a slightly acidic range of 6.0 to 6.8. If needed, adjust pH levels using lime or sulfur.

Mix in high-quality compost to improve soil structure and nutrient content. Use a ratio of 1 part compost to 3 parts soil. This blend provides essential nutrients and promotes good drainage.

Create raised beds or mounds to ensure proper water runoff. This step is especially important in areas with heavy clay soil. Add a layer of mulch around plants to retain moisture and suppress weeds.

Creating the Mold

Creating a square mold is essential for shaping watermelons into cubes. The mold provides structure and guides the fruit’s growth into the desired shape. A well-constructed mold ensures successful results.

Materials Needed

To create a square watermelon mold, gather the following materials:

• Polycarbonate plastic sheets (1/4 inch thick)
• Wood screws (1 inch long)
• Hand saw
• Drill with drill bits
• Measuring tape
• Pencil
• Safety goggles
• Work gloves

Polycarbonate plastic is ideal due to its durability and transparency, allowing light to reach the growing watermelon. Wood screws secure the mold pieces together firmly.

Building the Square-Shaped Mold

Start by measuring and marking the polycarbonate sheets. Cut four identical square pieces for the sides, each measuring 12 inches by 12 inches. Cut a fifth square for the bottom. Use the hand saw carefully, wearing safety goggles and gloves.

Drill small pilot holes along the edges of the side pieces. This prevents cracking when inserting screws. Assemble the mold by attaching the sides to the bottom piece using wood screws. Ensure the corners are square and tightly fitted.

Leave the top open to allow the watermelon vine to grow. Sand any rough edges to prevent damage to the fruit. The completed mold should be sturdy and able to withstand outdoor conditions throughout the growing season.

The Growing Process

Growing square watermelons requires careful attention to planting, vine care, and mold placement. The process combines traditional watermelon cultivation with specialized shaping techniques.

Planting the Seeds

Plant watermelon seeds in hills, with 9 seeds per hill grouped in clusters of 3. Space clusters about a foot apart. Press each seed 1/2 inch deep into the soil. Water thoroughly after planting.

Choose a sunny location with well-draining soil. Prepare the soil by mixing in compost or aged manure. Plant seeds after the last frost date when soil temperatures reach 70°F (21°C).

Thin seedlings to the strongest 2-3 plants per hill once they develop true leaves. This allows adequate space for vine growth and fruit development.

Caring for the Watermelon Vine

Water deeply and consistently, providing 1-2 inches of water per week. Increase watering during fruit set and development. Mulch around plants to retain moisture and suppress weeds.

Fertilize with a balanced fertilizer when vines begin to run. Switch to a fertilizer higher in phosphorus and potassium when flowers appear to support fruit development.

Train vines to grow in a desired direction. Prune secondary vines to focus energy on primary vine and fruit growth. Monitor for pests and diseases, addressing issues promptly.

Using the Mold

Select a young watermelon when it reaches about the size of a softball. Gently place it inside a square-shaped mold, typically made of plastic or glass.

Secure the mold around the developing fruit, ensuring it’s centered and has room to grow. The watermelon will naturally fill the mold as it matures.

Check the mold regularly to ensure proper fit and ventilation. Remove any debris or water that may accumulate. Harvest the watermelon when it reaches full size and the stem begins to dry out.

Harvesting and Aftercare

Proper harvesting techniques and aftercare are crucial for enjoying your square watermelons. Timing and careful handling ensure the best flavor and longest shelf life.

When to Harvest

Square watermelons typically mature in 70-100 days after planting. Check for these signs of ripeness:

• The tendril nearest the fruit turns brown and dries out
• The spot where the melon rests on the ground changes from white to creamy yellow
• The melon’s surface loses its shine and becomes dull
• A hollow sound when tapped gently

Harvest in the morning when melons are coolest. Avoid leaving ripe melons on the vine too long, as they can become overripe and lose flavor.

How to Cut the Stem

Use clean, sharp pruning shears or a knife to cut the stem. Leave about 2 inches of stem attached to the watermelon. This helps prevent rot and extends storage life.

Gently lift the melon from the mold. Be careful not to drop or bump it, as square watermelons can be more fragile than round ones.

Wipe the melon clean with a damp cloth. Store at room temperature for up to a week or in the refrigerator for 2-3 weeks.

Additional Variations

Square watermelons aren’t the only uniquely shaped melons that can be grown. Creative gardeners have developed techniques to produce melons in various eye-catching forms.

Heart-Shaped Watermelon

Heart-shaped watermelons offer a romantic twist on the traditional round fruit. To create this shape, growers place young watermelons into heart-shaped molds as they develop. The molds are typically made of plastic or glass and consist of two halves that clamp around the growing fruit.

Timing is crucial when shaping heart melons. The fruit must be placed in the mold when it’s about the size of a softball. If done too early, the watermelon may not fill out the mold properly. Too late, and it may not conform to the heart shape.

Growers must monitor the fruit closely as it develops. The mold may need adjusting to ensure proper growth and prevent cracking. Once fully grown, heart-shaped watermelons make unique gifts or decorative centerpieces.