11 Easy Steps in Growing Watermelons in Containers

Watermelons are sweet, juicy, and perfect for summer! If you want to grow this delicious fruit but do not have enough yard space, fret not! It is possible growing watermelons in containers.

In this post, we will share easy steps in growing watermelons in containers and other information about planting watermelons. 

What do watermelon plants look like?

Image source: commons.wikimedia.org

What is the smallest watermelon variety?

Image source: plantsmap.org

See Step 1 below to see more compact varieties of watermelon that you can grow in your yard or in containers.

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Where does a watermelon grow?

Watermelon plants can grow in containers or in your yard. They thrive in areas with tropical to temperate climates, needing temperatures over 25°C or 77°F to grow healthy. You may sow the seeds initially in pots in a shaded area and transplant them into well-draining loam soil or plant them directly in their permanent spot. When exposed to high humidity, they may be prone to powdery mildew and other plant diseases.  

When is the best time to plant watermelon?

The best time to plant watermelon is when the soil temperature is at least 21°C (70°F).  That is during late spring to early summer. 

How far apart do you plant watermelon seeds?

Proper spacing of watermelon plants helps utilize your space.  At the same time, it helps provide the best environment for your plant to grow.  You can plan for the spacing of your watermelon seeds depending on the variety of your watermelon.  A 3-feet space between seeds should be enough for smaller watermelon varieties.  You can give a safe distance of up to 12 feet for large ones. 

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How to prepare watermelon seeds for planting

Mature watermelon seeds are best for planting.  Since the seeds do not continue to ripen after harvesting the fruit, remember to reap your watermelon beyond its edible period.  You can be sure that watermelon has matured when the tendrils are totally dry and withered.

When your fruit is ready, you can slice your watermelon and remove its seeds.  Soak them in a bowl filled with water.  You will notice that some seeds will float, and some will sink.  Remove and dispose of those that float since they are unfit for planting.  The healthy seeds are those that sink.  Scoop the healthy ones and rinse off the sticky pulp.  Once done, spread them over a dry towel or newspaper.  Leave them in a sunny place to dry.  After a week, your watermelon seeds will be ready for planting. 

What are tips in planting watermelon from seed?

Here are some quick information and tips for planting watermelon from seed:

• Watermelon seeds are viable for 4 to 5 years.
• You can sow your watermelon seeds indoors and transplant seedlings to your yard after 6 to 8 weeks, ensuring the soil temperature is 21°C (70°F) or higher.
• Use peat pots will seed starting mix. Do not use garden soil as they tend to compact and dry up quickly.
• Ensure the indoor temperature is between 27-32°C (80-90°F) until watermelon seeds germinate. Then, you may shift to 24°C (75°F) with the seedlings.  
• You may directly sow watermelon seeds in your garden in springtime after the danger of frost has passed. Again, make sure the soil temperature is at least 21°C (70°F) soil temperature is 21°C (70°F).
• Watermelon seeds germinate within 3 to 10 days in warm soil and will not grow at soil temperatures lower than 18°C (65°F).
• Sow the seeds ½ inch deep and space them 3 to 12 feet apart, depending on the watermelon variety.
• Make sure the soil does go dry.  
• Fertilize your watermelon plant.
• Place your watermelon plant in full sun for the best produce.
• Avoid planting watermelons next to cucumbers or squash since they may cross-pollinate and result in poor-quality fruits.
• Watch out for common watermelon pest enemies like aphids, beetles, bugs, snails, and slugs.
• Look out for common diseases like mildew, wilt, and cucumber mosaic.  

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How long does it take to grow watermelon?

Watermelon seeds take between 4 to 12 days to germinate.  4 to 8 weeks after germination, watermelon plants begin to flower.  Once a flower has been successfully pollinated, it bears a fruit underneath that looks like a tiny green ball.  This ball will grow into a full-size watermelon in 30 to 40 days.  So, from the sowing of seeds, you can harvest a ripe watermelon in 70 to 90 days, depending on the variety. 

How much water do watermelons need?

Watermelon plants need moist soil to thrive, but not waterlogged.  Apply 1 to 2 inches of water per week with extra dampening when the weather is scorching.  Water near the vine’s base and not on the leaves or fruits to avoid plant diseases.       

What are trellis ideas for watermelon?

If you have limited garden space or want to grow watermelon in containers, you can support your watermelon plant with a trellis.  Here are some great trellis ideas that you can use for the watermelon plant:

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Can you grow watermelon in a pot?

Growing watermelon in a container is possible.  You can use a 5-gallon pot or larger with enough drainage holes.  Since garden soil can easily compress and dry out, use a soilless mix that makes it easy for your watermelon plant to thrive.  Choose a compact watermelon variety (LINK STEP1) that grows smaller fruits.  You also need to support your growing watermelon using a trellis.         

What are the steps in growing watermelons in containers

Not only ornamental plants, herbs, and smaller vegetables and fruits grow in containers. Watermelons can thrive in pots and planters, too. It just gets a little tricky. To be successful in growing watermelons in containers, follow these steps:

Step 1: Choose a compact variety watermelon

The compact types of watermelons are those with smaller fruits. This is great for growing watermelons in containers or with limited space. The following are some varieties you can consider:

Crimson Sweet watermelon	source: befunky
Early Moonbeam watermelon	source: befunky
Golden Midget watermelon	source: plantsmap.org
Jade Star watermelon	source: morningchores.com
Jubilee watermelon	source: befunky
Moon and Stars watermelon	source: growables.org
Orange Sweet watermelon	source: pexels
Solitaire watermelon	source: befunky
Sugar Baby watermelon	source: pixabay
Yellow baby watermelon	source: goodeggs.com

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Step 2: Pick a deep large pot

Watermelons have long taproots and grow pretty quickly. They also need plenty of water. For these reasons, you need a deep, large container for your watermelons. A 2-feet deep and 1-foot wide pot with enough drainage holes should suffice.

Your container also needs to be heavy to support the growth of your watermelon plant. If you think your pot is not that heavy, you may add a few rocks at the bottom.

Step 3: Use sandy, loamy, and nutrient-rich soil

Watermelons love sandy, loamy, and well-drained soil with optimal pH (acidity) of 6 to 6.8. Avoid using soil from your garden as they are compact and will harden quickly. Since watermelons are planted in containers where their roots cannot freely get nutrients, be sure to use nutrient-rich soil. You can add horse, cow, or rabbit manure, as well as worm castings. Do not forget to remove any weeds, clay, or debris from the soil.

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Step 4: Sow your seeds

You can sow your watermelon seeds directly to the pot where you will grow them or sow them in peat pots.

Sowing directly to your big pot

Some experts advise sowing watermelon seeds directly in the pot where you will be growing them. That is because watermelons have delicate taproot that does not transplant well. If you choose this method, be sure to sow only three seeds at most in one pot. Germination should take place between six to ten days. From the seedlings that sprout, choose one that appears the strongest. Pinch out the other seedlings.

Starting seeds in biodegradable pots

You may also want to start growing watermelon seeds indoors in biodegradable pots, such as peat pots. This method is said to help lengthen their growing season.

• Use soilless potting mix.
• Sow two seeds in each peat pot and cover with 1/2 inch of soilless mix.
• Bottom water by putting a water-filled plastic tray at the bottom of the pot.
• Keep your pot in a warm place.
• Keep the soil moist but not soggy.
• As soon as the true leaves appear, leave the strongest seedling and pinch out the rest.
• Put your seedling in a sunny location or under a grow light
• Once established, transplant your seedling to your big pot along with the biodegradable pot.

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Step 5: Provide your watermelon plant with support

As your watermelon plant grows and bears fruit, it needs support. You may use a trellis or a teepee. Train the plant to climb by loosely tying the watermelon vines with foam-padded twist ties or cloth strips to the support.

Step 6: Position your watermelon in a sunny location

Watermelons need full sunlight and warm soil to thrive. They need at least 6 hours of daily sunlight to grow well. Its sunlight exposure is also the one responsible for giving its fruits their sweet taste. So if you notice your fruits are bland, they may not have received enough sunlight while they were growing.

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Step 7: Keep the soil moist

Be sure to water your plant daily to keep the soil moist. Water your watermelon plant twice daily on warmer days (higher than 80 F or 27 C). Reduce watering as fruits begin to mature, but be sure not to underwater it.

Step 8: Use liquid watermelon fertilizer

Watermelons require a lot of nutrients. Being restricted in containers, they depend on the nutrients you feed them as they grow. When growing watermelons in containers, you need to remember to fertilize once a week with liquid fertilizer. You may also use granulated slow-release fertilizer at least once a month.

As your plant develops flowers, you may begin to use liquid fertilizer with less nitrogen, such as a liquid seaweed fertilizer.

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Step 9: Hand-pollinate when needed

Pollination is necessary in watermelons since they produce male and female flowers separately. If there are not many butterflies and bees in your area, you may need to hand-pollinate them as soon as the flowers start to develop. This will ensure you will have fruits to harvest in the coming days.

Do not be intimated. It is quite easy to hand-pollinate. Here are the steps:

• Look for the male flowers and pick one. They are the ones that are directly attached to the stem of the watermelon.
• Identify the male flower’s stamen. It is fuzzy pollen found in the center of the male flower.
• Spot the female flowers. They are the ones that sit on top of what looks like an immature watermelon fruit.
• Find the female flower’s stigma. You can identify it as the fuzzy center of the female flower.
• Tap the stamen of the male flower to the stigma of the female flower to transfer the pollens. You may also use a soft brush to transfer the pollens from the male flower to the female flower.
• Do this consecutively for several days to increase your chance of success.
• Observe the immature fruit where the female flower attaches. If there is any growth in the following days, it means you have succeeded in your hand pollination.
• If there is no growth, you can always try again.

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Step 10: Support the fruits with large mesh bags

When you are growing watermelons in containers, their climbing vines and stems may not be able to support their growing fruits. You can support the watermelon fruit by creating a cradle or hammock under it using a stretchable material. You can use a mesh bag, a shirt, or a pantyhose with ends tied to your trellis.

Step 11. Harvest your ripe watermelon

How will you know your watermelon is ready for harvest? There are different ways to tell or at least estimate.

• Check your seed packaging. It usually indicates the number of days until you can harvest your watermelon fruits.
• It generally takes between 30 to 50 days after flowering for your watermelon fruit to be ready for harvest.
• Check the tendrils of the fruit that grows on the ends of your fruit. When these green curly stems start to turn brown, you can harvest the fruits real soon. If they turn dead, they are either ripe or overripe.
• Look at the stem that connects to the fruit. If it has a split or crack, this means that the fruit is already ripe. Harvest it. Do not wait for the fruit itself to crack.
• Knock on the watermelon fruit using your fingers. If it makes a hollow sound, then it is ripe and ready for harvest.

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Other tips for growing watermelon plants in containers

Here are other things to keep in mind when growing watermelons in containers:

• Allow the main vine to grow and prune some side branches before they grow. This will ensure a healthier and more productive watermelon plant.
• Constantly check for and remove stems that are diseased or withered.
• Limit the number of fruits growing in your plant at a time to ensure great quality fruits. You can have 4-5 fruits for smaller varieties and 2-3 for larger ones.
• Bland and less flavorsome watermelons may be caused lack of sunlight, under or overwatering, changes in temperature, pests, and diseases.
• Common pests that may infect watermelons include melon aphids, cucumber beetles, and squash vine borers.
• If you want to harvest watermelons regularly, plant 2-4 plants at one time. Do the same after 2 weeks.

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Watermelon storage container ideas

Image source: wikihow.com

Have you tried growing your watermelons in your urban garden? We would love to hear your tips.

You may also want to read about our guide to urban gardening: Urban Gardening: The Ultimate and Best Guide

Sources:

• https://www.gardeningknowhow.com/edible/fruits/watermelon/growing-watermelons-containers.htm
• https://balconygardenweb.com/growing-watermelon-in-containers-and-pots-vertically/
• https://homeguides.sfgate.com/plant-watermelons-container-22122.html
• https://calikimgardenandhome.com/growing-watermelon-in-a-container-3-tips-for-success/
• https://gardendiyideas.com/grow-watermelon-pot-vertically

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