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Citrullus lanatus

Importance to Oregon

Watermelon is the 26th ranked product of all products grown in Oregon. Watermelons grow best in the warmer areas of the state like Hermiston, Medford and the Snake River Valley. Hermiston is known for their watermelons that are juicy and large in size.


Watermelons can be traced to prehistoric times through pictures drawn by the ancient Egyptians that are still available to view to this day. About a hundred years ago, David Livingston discovered the answer to the question of where watermelons originate from. The answer to this question is Central Africa were the ground is completely covered with a chaotic amount of watermelon vines.

Watermelons act as a very important source of water for Central Africans during the dry season. There are still districts in Africa where watermelon is cultivated for the purpose of being used for water.

Watermelon was brought to the America’s by European colonists and could be found in Massachusetts in 1629.


Seedless watermelons have only been on the market for the last 50 years, but have become a consumer favorite. The little white shriveled up seeds in “seedless” watermelons are not actual seeds because they are not fully mature. They are completely safe to eat and you will not grow a watermelon in your stomach like some stories say.

This variety of watermelon often weighs between 10 and 20 pounds and have the normal sweet flavor as the seeded watermelons.


Yellow watermelons have a yellowish to orange flesh with the normal green rind. They can either have seeds or be seedless. They might come in a round shape or oblong shape to them. Yellow watermelons often weigh between 10-30 pounds. The flavor is a little bit different than that of a seeded or seedless watermelon. It is described as a sweeter or “honey-like” taste than regular watermelon varieties.

Icebox Melons

Icebox watermelon gets its unusual name because of its small size. They range between the weight of 5-15 pounds. This smaller size watermelon allows for them to fit in the refrigerator. These melons are grown specifically to feed a single person or only a small family.

Life Cycle of a Watermelon

Watermelons start as seeds that are planted in the ground. The seed then sprouts and the vine begins to grow. The vines grow into long vines with different sized leaves and flowers. Just like other fruits, the flower is where the actual fruit product comes from in this early stage of life. Once the flower has developed, it turns into a “green watermelon.” This has a similar appearance to a ripe watermelon, but this fruit is a much smaller fruit and has a more pale green than the ripe fruit. It takes the fruit about 45 days to become a full size and ripe melon. Next, the ripe watermelon is ready to be picked. The farmer is able to tell when the watermelon is ripe because the vines and leaves start to turn brown and die. This is when the harvesting period is over.


Watermelons are ready to harvest around 65-90 days after the seed has been planted. The growth time of watermelons can often differ from varieties because of size. One way that farmers know that a watermelon is ripe is by looking at the vine tendrils. These are the little curly vines that are found on the larger part of the vine when the watermelon is growing. When the watermelon is ripe, the tendrils will turn brown and die. A green tendril means the watermelon is not ripe and should not be picked.

The watermelons are hand cut off of the vine and harvested. Watch the video below to learn a little bit more about watermelons grown here in Oregon!



Pests and Diseases

Just like any other fruit or growing thing, there is a chance that watermelon plants may come in contact with a fungus or disease that effects the growth rate and production of the plant.

Downy Mildew

Downy mildew is a fungal disease that affects the leaves of a watermelon plant. This fungus causes the leaves to turn yellow and curl inwards. One way to avoid this fungus is by keeping enough room between plants and watering the plants from under the plants instead of the water landing on the tops of the plants.

Bacterial Fruit Blotch

Bacterial fruit blotch is a bacteria that is caused by “small water-soaked lesions” that are on the fruit. These spots will get bigger and can end up covering a large portion of the melon. These spots turn a reddish or brown color and will eventually crack. this bacteria can be spread through seeds that carry the bacteria or through water. This disease is more common in wet conditions. One way to avoid this bacteria is to not use overhead irrigation.


Cutworms destroy young plants or seedlings by cutting them at the soil line. They eat holes into the fruit and stems which causes them to break. Cutworms attack the plants at night and hide in the soil during the day. These pests are only one to two centimeters in length.


Watermelon is mostly used for the purpose of being a delicious snack during the summer time. This fruit is most enjoyable when eaten cold!


Vocabulary Terms

The juicy part of the fruit that you eat.

The hard outer layer of the rind.

The part of a plant whose stem requires support and which climbs by tendrils or creeps along the ground.

A leaf or stem in the shape of a coil that supports the sensitive part of a climbing plant.