How Do Watermelons Grow? – Commercially & In the Garden

Almost all watermelons are grown in fields. Watermelon plants are either started indoors or direct seeded into the ground.

Seedless varieties of watermelon are always started indoors because the seeds are expensive and farmers want a good germination rate. Drip irrigation hose and black plastic mulch are used depending on the farmer.

This row cover is opaque and keeps the sunlight from reaching the surrounding area of the plants which keeps the weeds out.

Although clear plastic mulch will warm the soil temperatures higher it also lets sunlight in and weeds can grow underneath it. This is why farmers use black plastic mulch. Still it is an extra cost that farmers weight the pros and cons of. Watermelons are always harvested by hand.

This paper from the University of Georgia is very detailed about commercial watermelon production in the state and outlines a sample budget towards the end. This paper from Penn State University is less detailed but does the same.

You might also be interested in “Stages of Watermelon Plant Growth

Choosing the Variety of Watermelon to Grow

The main decision that a farmer or gardener needs to make is what type of watermelon to grow. Farmers make this decision based on which varieties they believe the market wants and will demand a higher premium. The size of the watermelon, seeded vs. seedless, and the color of the outside and the flesh are all considerations.

Common seedless types grown include Nova, Millionaire, Crimson, and King of Hearts. Commonly grown seeded varieties include Charleston Gray, Crimson Sweet, Jubilee, Sangria, Stargazer, and Black Diamond types.

These lists are not at all conclusive. Check this article out to learn more about the different types & varieties of watermelons.

How Seedless Varieties of Watermelon Grow

Seedless watermelon seeds are expensive. Farmers will almost always start seedless watermelons indoors to increase the germination rate and not waste the expensive seeds.

When growing a seedless watermelon variety a seeded watermelon variety also needs to be grown in the same field at a ratio of 3:1.

The reason a seeded variety is needed and spread throughout the field is that the seedless watermelon variety needs pollen from the male flowers to pollinate the female flowers in order for watermelons to grow. The male flowers of the seedless watermelon variety plant do not produce viable pollen.

The seeded variety needs to look different from the seedless variety so that when harvest time comes there is no mix-up. Also the flowering times of the two varieties need to be lined up so that pollen is available when female flowers arrive on the seedless varieties.

Sometimes successive planting of the seeded variety is done to make sure there is pollen available during the entire pollination window of the seedless variety watermelons.

When growing a seedless watermelon variety farmers also need higher numbers of bee colonies to ensure pollination. This is because the majority of male flowers the bees will visit in the field will have sterile pollen.

Instead of an average of 8 visits by a honeybee to a female flower around 24 visits from a honeybee will be needed for successful pollination.

Do Watermelons Grow on Vines or Trees

Watermelons grow on vines and do not grow on trees. However the vines can be trained up supports vertically and then sideways and in this way watermelons can be suspended and hang as if they were growing on trees.

How Do Watermelons Grow Vertically

This gardener grew his watermelons vertically in a small bed.

With a little assistance watermelons can be grown vertically up a trellis or other support. Watermelons are sprawling vine plants and growing them vertically can save a lot of space in the garden. It also makes for a healthier plant by giving foliage more sunshine and air circulation.

To grow a watermelon vertically you need to use garden ties to secure the vine to the support. The tendrils of the watermelon plant are not strong enough to hold onto the support alone.

Once watermelons start to develop they need to be supported. Each heavy watermelon needs to be tied to the support.

Please comment below with any thoughts or experiences you have about growing watermelons!

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