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.
Table of contents
- Step 1: Choose a compact variety watermelon
- Step 2: Pick a deep large pot
- Step 3: Use sandy, loamy, and nutrient-rich soil
- Step 4: Sow your seeds
- Step 5: Provide your watermelon plant with support
- Step 6: Position your watermelon in a sunny location
- Step 7: Keep the soil moist
- Step 8: Use liquid fertilizer
- Step 9: Hand-pollinate when needed
- Step 10: Support the fruits with large mesh bags
- Step 11. Harvest your ripe watermelon
- Other tips for 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 great for growing watermelons with limited space. The following are some varieties you can consider:
|Crimson Sweet watermelon|
|Early Moonbeam watermelon|
|Golden Midget watermelon|
|Jade Star watermelon|
|Moon and Stars watermelon|
|Orange Sweet watermelon|
|Sugar Baby watermelon|
|Yellow baby watermelon|
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.
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.
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.
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 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.
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.
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.
Other tips for growing watermelons 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.
This is how you can be successful in growing watermelons in containers. 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