Learn how to grow watermelon in pots. Growing watermelon in containers allows this big, sweet and juicy fruit to grow in smallest of spaces.
Sweet and watery watermelons are without a doubt an iconic summer fruit due of their high water content and soft red flesh. Those supermarket melons can’t be like homegrown fresh and organic melons. You can even plant them in a small space like a balcony, it is possible by growing watermelon vertically in a pot.
Propagation and Planting Watermelon in Pot
Watermelon has long taproot and it doesn’t transplant well that’s why it is better to sow the seeds directly in a pot. Sow 3-4 seeds directly in a pot once the temperature starts to reach 65 F (19 C) and above in the spring. In tropics (USDA Zone 10-11), the best time to sow seeds is winter and early spring. The germination takes place within 6 to 10 days. Thin out and leave only one of the strongest seedlings per pot.
Choosing a Pot
Growing watermelon in containers is not much difficult though tricky. You need to understand the basics. As watermelon has long taproot choosing a deep pot is essential. A large pot or bucket that is at least 2 feet deep and half wide is required.
To know everything about watermelon varieties, see this excellent guide at Washington State University site.
Requirements for Growing Watermelon in Containers
Watermelons should be grown in a sunny position. If you’re growing it on a balcony or on a roof garden where space is tight, growing watermelon vertically on a trellis is a solution. Trellis should be minimum 4 feet tall and sturdy enough to carry the weight of melons.
Watermelons are warm weather annuals but they can be planted in both tropical and temperate regions easily. It is possible to grow watermelons in temperature around 50-95 F (10-35 C). The optimum growing temperature is around 65-85 F (18-30 C).
Sandy and loamy soil is suitable for growing watermelons. Ideal soil pH is around 6 – 6.8. Avoid compact, clayey soils. Airy and well-drained substrate promotes the growth of the plant. Also, application of the well-rotted horse, rabbit or cow manure improves the texture of soil and provides nutrients constantly.
Watermelon requires a lot of water. Keep the soil evenly moist but not wet, the water must drain freely from the bottom. When growing watermelon in containers, you’ll need to water the plant every day and sometimes twice in a warm day. Once the fruits start to swell up and mature, reduce the watering. In that period, water carefully and moderately. Avoid overwatering and underwatering both to get the sweetest melons.
Watermelon Plant Care
Start to fertilize the plant with a complete liquid fertilizer. Once, the plant starts to flower and appear to set fruits, use a fertilizer with less nitrogen. Consider liquid seaweed fertilizer.
To get a healthy and more productive plant, only allow the main vine to grow. When the plant is young, remove side branches before they grow more. Also, remove those stems that are damaged and diseased.
Watermelon vine produces both male and female flowers separately. However, pollinators (bees and butterflies) will pollinate them but to be sure you’ll need to hand-pollinate the flowers to make sure you get fruits. The first ripe fruits appear after approx. 40 days after pollination of flowers.
Diseases and Pests
Usually, you can easily care and look after the watermelon growing in a pot. Still, it is little prone to diseases when exposed to too hot-humid or too cold weather, or due to waterlogged soil. Common garden pests like aphids, cucumber beetles and those that affect the squashes and cucumbers can infect it.
The harvesting period depends on the climate, season, and variety. Generally, it usually begins 80-90 days later after seed sowing and between 30 to 50 days after flowering. Flowering and fruit setting continue for several weeks until the weather remains favorable and you’ll get several harvests.
Ripe fruit does not seem special. Smell and no change in color of the skin occurs. To see if the fruit is ripe, you should knock with fingers on the surface of the watermelon. If you hear a dead, hollow sound, this means that the fruit is already ripe. Another method is to check the tendril if it is fading and half dead then your watermelon is almost ripe. If it is faded, the fruit is ripe or overripe.
- In cool short summer climates, start the seeds indoors or in a greenhouse either directly in a container or in a biodegradable pot.
- Use a lot of organic matter for growing watermelons in containers as they are heavy feeders. Side dress your potted melon plant with manure or compost in every 3-4 weeks. Scrap and remove topsoil if there is no space in the container.
- Stress (change in temperature, pests or diseases, overwatering or lack of water) to the plant at the time when fruits are maturing, results in less flavorsome and sweet fruits.
- In a small space, growing melons vertically on a trellis is a great way to save space. Use netting, a bag or a stretchable cloth to create a hammock under the fruit to support it.
- The trick for getting best quality fruits is to don’t let the plant set so many fruits. 2-3 fruits at the same time for large fruit varieties and 4-5 fruits for the smaller one is sufficient.
- Do successive planting for regular harvests. Plant 2-4 plants and do the same after 2 weeks.