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Tips for Growing Watermelons

Maya Pillai Oct 30, 2018
Interested in gardening? Try growing watermelons in your backyard.

Did You Know?

Today, China is ranked as the largest producer of watermelons in the world!
Research shows that watermelons originated thousands of years ago in Kalahari Desert in Africa. Hieroglyphics unearthed from excavations in Egypt revealed that watermelons were cultivated and harvested in Egypt 5,000 years ago.
Gradually, watermelons found their way into Mediterranean countries via the sea trade route. Watermelons were cultivated in China during the 10th century and around the 13th century, the cultivation of watermelons spread throughout Europe.
The term 'watermelon' was first mentioned in the English vocabulary in the early 17th century. The botanical name of watermelon is Citrullus lanatus and it is related to the cucumber family. Today, U.S.A is the fourth biggest producer of watermelons in the world.
It is unimaginable to spend hot summer days without eating some form of watermelon! If you have a small patch in your backyard, you could grow your own sweet and refreshing watermelons. There are some tips for growing watermelons.

How to Grow Watermelons

Watermelons grow well in USDA Hardiness Zones ranging between 3 to 11. These plants thrive in dry and high temperatures. Daytime temperatures ranging at 80-95°F or 26-35°C and nighttime temperatures of 65°F or 18°C are optimal for watermelons to grow.
Seeds must be planted in spring, when the weather is warm and completely free of frost. Watermelon plants need plenty of sunlight and well-drained soil with a pH level between 6.0 to 6.8. Even though these fruits grow in humid soil, the chances of developing diseases are more.
You could either sow the seeds or buy saplings from a nursery. Some popular varieties of watermelon include Charleston Gray, Triple Crown, Crimson Sweet, Sugar Baby, and Black Diamond.
These plants need a fairly large amount of space to spread out and grow. For those with less garden space, growing these plants upwards on sturdy tendrils is the ideal method to follow.
The vines of the watermelon plant are not natural climbers, but can be made to climb by using metal tendrils. When using tendrils, the fruits will tend to hang and thus, must be provided support by tying a sling/hammock underneath each fruit or making shelves for the fruits to rest.
Before planting the watermelon seeds, choose an area that receives lots of sunshine and is protected from winds. However, make sure there is ample air circulation around the selected spot.
Ready the soil by conditioning it with rich compost. The next step is to make the soil fertile by adding organic fertilizers and tilling it to mix all ingredients into the soil. Sandy and fertile loam, that retains moisture but is well-drained is the best for watermelons. You can prepare the soil by adding manure, compost, and dead leaves.
Rake the soil to build planting mounds before planting the seeds. The mounds must be at least 3 inches tall and 15-18 inches wide so as to ease drainage. These plants do not like wet feet and thus grow better on raised planting mounds.
If you are using seeds, soak them in compost tea few minutes before sowing. Plant one seed in each mound in a hole 1 inch below ground level. If you are planting the saplings right from the nursery, remove them from the polythene cover in which they were first grown. Slowly put them in 1 to 2 inch deep holes. Provide sufficient space between two plants.
Now, you will need to make a dish around the seed or sapling, so as to retain water. Pour adequate water into the dish. Watering once a week is more than enough for watermelon plants to thrive.
Mulch the area properly and leave the soil around the seed untouched, so that it gets to absorb plenty of heat and grows robust.
Keep the watermelon patch clean. The size of the fruit depends upon the fertility of the soil. Once in a while, spray the plants with seaweed or liquid fertilizer. Reduce the usage of nitrogen fertilizers once the watermelon plants start to flower. However, add potassium and phosphorous fertilizers until the harvest time.
One of the best ways to keep the air and soil warm on a frosty day is to cover the watermelon patch using floating row cover. However, once the flowers start blooming, remove this cover.

Using the Transplant Method

Transplanting the watermelon plant also works well, as it gives the plants the upper hand. Transplants tend to bear fruits a week earlier than seeded varieties. To grow transplants, you will need to grow out the seeds at least four weeks before planting in the garden. The seeds must be started in containers 2 inches wide and allow plenty of drainage.
These seeds will take 4-6 days to germinate and during the period of 4 weeks, the seedlings would have developed strong roots that would help the plant grow faster after being transplanted into the garden.
It is essential that the transplanted seedlings are hardened off for the next 7-10 days, before being shifted to the garden bed. During the hardening-off period, the seedlings must be given very little water in order to slow their growth. The seedlings must be kept in a place with relatively cooler temperatures.
When the transplants have 2-3 true leaves and are 4-5 inches tall, they must be planted in the garden mounds.

Other Essentials

Pest and Disease

Some of the potential pest and disease that may hamper the growth of watermelon plants are; anthracnose, gummy stem blight, mites, cucumber beetles, alternaria leaf spot, fusarium wilt, and aphids.


Being heavy feeders, the garden bed must be treated with 3 pounds equalized fertilizer of nitrogen, phosphorus, and potash before planting the seeds or saplings.
Feed the plants again after the vines have begun running and the third, after first fruit is harvested.


The male flowers of the watermelon plant appear first and do not yield any fruits. The male flowers appear on the vines and are comparatively smaller than the female (pistillate) flowers. The female flowers need to be pollinated in order to develop fruits.


A watermelon planted from seeds will be ready for harvest after 85-95 days of planting. However, some smaller and rounder varieties of watermelon take 75-85 days to mature.
Watermelon plants grown from transplant seedlings will mature a week earlier than their seeded counterparts. If the curly tendrils near a watermelon have turned brown or have dried, it is a clue that the fruit is ripe.
If the underside of a seeded variety of watermelon has turned from light green to creamy-white, if it is ready for harvest. In case of seedless varieties, the color of the underside of the fruit would change from light green to golden-yellow.
Yet another clue to check whether the fruit is ready for harvest is, thumping a watermelon. If it is ripe, you would hear a dull and hollow sound. Whereas, in unripe watermelons, the sound heard is heavy and metallic.
You may consider pinching off the vines after its initial few blossoms have appeared, so that larger and better quality watermelons can be produced.
However, for smaller fruits and greater yield, the vines should be pinched off only after they are 5-7 feet long.