Growth of a Square Watermelon

Watermelon Growth

• Watermelon rinds may feel hard and ridged, but they're actually quite malleable as they grow. Their natural inclination is to grow and swell out round and full; but if you look at the ground side of a watermelon, you'll notice that it's flat. Since that part of the watermelon can't push out and up, it takes on the flat shape of the ground instead. The same basic principle applies with square watermelons. When placed inside a square structure, the watermelon takes on that shape.

The Box

• Though watermelons grow slowly and adapt to their surroundings, the wrong box could eventually burst under the pressure of the expanding rind. This means that your box must be stronger than the watermelon. Cardboard could work for a time, but you'll eventually need to switch it out for a more ridged material. The material must be translucent or transparent, allowing sunlight to filter into the fruit. The box must also have at least one open side to allow the watermelon to breathe. One option is a box made of green Plexiglas with a slot for the melon's stem and vine. You can either build a box yourself or purchase one from a specialty farming store or website.

Planting the Watermelons

• Square watermelons don't start out growing in a box. If you tried to cover the seeds with a box right away, the seeds may not sprout due to lack of proper sunlight. Square watermelons actually start life like all other watermelons. They sprout a vine, leaves and then tiny melons about the size of a quarter. The box doesn't actually come into play until the watermelon is relatively large.

Shut the Box

• According to the Urban Farmer Seeds website, watermelons about twice the size of a softball are ideal for box growing. At this stage, they're mature enough to withstand the environment inside the box. They're also large enough that you shouldn't have to change the box more than once, if at all, before the watermelons are ripe. Each watermelon simply slips inside its own box. Boxes with stem slots lie on their side with the open part facing the right or left. Boxes without this slot have the open side facing upward. The watermelons should ripen and harvest just like their round cousins.