Growing Watermelons Hydroponically- a Full Guide

Introduction to growing Watermelons Hydroponically

Watermelon fruit is a sweet and refreshing low-calorie summer snack. It provides hydration and also has essential nutrients, including vitamins, minerals, and antioxidants. Watermelon is a plant species in the Cucurbitaceae family. Hydroponic systems use a soilless medium and liquid nutrient solutions to grow fruits. In this article we also discussed the following topics;

  • Hydroponic Watermelon growing conditions
  • Hydroponic Watermelon growing medium
  • Hydroponic systems for growing Watermelon
  • Hydroponic Watermelon production
  • Hydroponic Watermelon nutrients

A step by step guide to growing Watermelons Hydroponically

Hydroponics system is a soil-less cultivation practice that uses nutrient-rich, pH-balanced water to grow plants. The technique is beneficial for those with limited space because it does not require large amounts of soil for root growth and expansion. Other benefits of hydroponic farming include a quicker grow period, larger harvests, and reduced interference from pests and weeds. And the main problem with growing Watermelons hydroponically is the plants have sufficient light and support for their weight because Watermelons can become heavy.

In case if you miss this: Growing Vegetables in Shade.

A guide to growing Watermelons Hydroponically.
A guide to growing Watermelons Hydroponically.

Requirements for growing Watermelons Hydroponically

Hydroponic-system is an excellent way to increase fruit yields over conventional soil gardening, and it allows gardeners to grow fruits that would otherwise not be possible in their climate or soil.

Lighting for growing Watermelons Hydroponically

Your Watermelon tree will need plenty to have like to grow, no surprise there. How much light your Watermelons tree needs can vary, but expect to be providing a solid 8 to 12 hours daily. You need to provide trees with some special growing lights. That means you’ll want to invest in metal halide lamps, high-pressure sodium lamps, or LED growing lights. The good news is that the lights will help with your issue of keeping enough heat around your Watermelon tree.

Watermelons need a significant amount of light to grow and thrive. For proper growth and development, Watermelons must receive 8 to 10 hours of direct light per day. If the hydroponic garden is located in a greenhouse, this light will come in the form of natural sunlight. Indoor hydroponic systems need to be dedicated grow lights to supply the necessary light exposure, as standard indoor lighting is insufficient. Periodically trim the plant leaves if necessary to prevent them from growing too large and blocking light to other leaves on the Watermelon vine.

Ideal hydroponic temperature for growing Watermelons

With your lighting, you must have less work to do in maintaining heat. To be sure your tree is warm enough, keep a thermometer in a growing area, and routinely check the water temperature. Remember, different species have different temperature level preferences, but so do trees of different ages. Seedlings prefer being grown in a solution with a temperature between 21 and 23°C. Older trees can tolerate a wider range, usually anywhere between 18 and 26°C.

Ventilation and humidity for growing Watermelons Hydroponically

Your ventilation doesn’t need to be a super-advanced system, but make sure you have got adequate air movement. This helps trees get CO2 to convert, and it gives the helpful bonus of preventing harmful mold and fungi. Then, this is where you’ll need to do a little research on the type of tree you’re planning on growing.

The nutrient solution for growing Watermelons hydroponically

If you’ve got an established hydroponics system, you’re no stranger to adding in a nutrient solution. Make sure your nutrient combo is right for the tree you’re growing, and always remember to start at lower nutrient levels and work up.

Watermelons grow well with general-purpose fertilizers. A homemade hydroponic system solution involves 1 teaspoon Epsom salts and 2 tablespoons general-purpose fertilizer mixed into 1 gallon of normal water. Any nutrient solution used when growing Watermelon in a hydroponic garden must be drained and replaced every 2 to 3 weeks to ensure that it contains sufficient nutrient levels.

Support structure or trellis for growing Watermelons Hydroponically 

Watermelon vines need a trellis or other support structure to grow hydroponically. Depending on the obtainable space, the support structures can be oriented horizontally or vertically alongside the hydroponic units. For vertical supports, nylon mesh netting attached to a horizontal tensile wire will support the Watermelons and keep them from snapping off the vine. Smaller Watermelon varieties are suitable for vertical supports; this will maximize melon production and prevent the Watermelons from growing too large to be properly supported.

Watermelons can be planted much closer together in a hydroponic than they can when planted in soil as they do not need to compete for nutrients. When they are planted close together, training the vines to grow on a trellis minimizes the overall area required to grow Watermelons as well as keeps the fruit off of the ground. Vines are tied or clipped to a sturdy trellis as they grow, and extra care needs to be taken to make sure the developing Watermelon fruit is fully supported so the vine doesn’t break.

Hydroponic systems suitable for growing Watermelons

Most hydroponic systems are suitable for Watermelons. If multiple plants are being grown, and then an ebb-and-flow system is the best option because it uses a single reservoir to give nutrients to multiple hydroponic units, reducing the amount of time spent checking nutrient levels and adding more solution. Though, smaller hydroponic setups, a floating hydroponic system allows one or more Watermelon plants to stay suspended above a container of nutrient solution.

Watermelons will produce in virtually any kind of hydroponic system, provided it is large enough to support the big vines. A hydroponic bucket system, where the plants are grown in individual buckets, works well, but it can be labor-intensive as the nutrient solution level must be checked frequently in each bucket. An ebb and flow hydroponic system is a better choice as multiple containers are fed from a single tank, so there is only one place to check liquid levels instead of many.

An ebb-and-flow system works great when you’re growing many Watermelons, but you can also use a floating system (the planter floats on top of the water) with DWC if you’re growing a single plant.  Don’t forget that Watermelons are a vine plant, so check regularly to make sure the Watermelon fruit is well supported.

Ebb and Flow Hydroponics – This is a hydroponic system where you put pots over a reservoir. The Watermelon plants sit on a tray above it, with the roots dangling through the bottom into the water. The nutrient solution is then pumped into the pan and this in turn flows past the roots. Any extra nutrient solution is allowed to ebb back into the reservoir for the next feeding.

Hydroponic Watermelon growth medium

The right hydroponic medium makes all the difference. When you choose to grow hydroponically, you still need to root plants in something. Growers tend to use materials such as rock wool. But you can use sand and gravel. Pop rocks are also a popular hydroponic grow medium and these are pelleted shale. They hold and transmit water well, and the small pellet balls are very easy to clean. Though, these can be difficult to find.

The important aspect of using an alt-medium is to make sure it is completely sanitized. Lava rocks, another popular grow medium should be soaked for as long as 5 days. They must be completely cleaned between grows. The right reservoir is also a crucial component of hydro growing success. When picking a reservoir, you want to keep the following issues in mind. It needs a lid and it needs to be close to a water source. You might need an extra standby reservoir and try to have at least one more close by. This way, you can pre-filter your water, remove the chlorine, and neutralize your pH level before feeding the plants.

Your reservoir will need to be well-insulated. Ten, this will make sure you can control the temperature. By elevating your reservoir with a few bricks, you allow air to flow around it. Some growers insulate their reservoirs with Styrofoam or foam rubber. A sterile, inert growth medium is very important when growing Watermelon in hydroponic units. Clay-based growth media or pea gravel provides additional support to help hold roots in place and lighter options that hold liquid better include peat moss, coconut coir, and pine bark shavings. Mineral-based media such as perlite and vermiculite can be used as well, as an artificial growth media designed particularly for hydroponic use. Sand can be mixed in with clay or gravel growth media to develop water retention if necessary. While Watermelon vines are so large, it is best to root them in an inert growth medium that gives the plant some support as it grows. Perlite works well as a growth medium, but growers can prefer something heavier, such as clay pellets, pea gravel, or silica stones. Any of these will add weight to the container the Watermelon vine is growing in, so providing some extra stability.

The growing process of Hydroponic Watermelons

Watermelons must be started from seed to grow in a hydroponic system. Start seeds in rock wool or peat starters, watering as required keeping the starter moist until the Watermelon plant begins to grow. Once the Watermelon plant begins forming visible roots, transfer it to the growth medium and provide it with nutrient solution. When flower development occurs, pollinate female flowers using the stamen of male flowers to encourage Watermelon fruit production. Harvest the Watermelons when the tendrils closest to the melon begin to dry out and turn brown or when the white spot on the rind that rests against your support structure turns yellow.

Gardening tips for growing Watermelons hydroponically

You may also check this: Growing Peppers in Pots from Seed, and Cuttings.

Tips for growing Watermelons Hydroponically.
Tips for growing Watermelons Hydroponically.
  • Using the right size reservoir is important to growing successfully in hydroponic systems. If your reservoir is too small, that could cause you several problems. So sizing a reservoir for the type of plants you’re growing, as well as how many your growing in your system is key. If you can’t grow hydroponic plants in natural sunlight, you’ll need artificial lighting to grow them.
  • Hydroponics is practiced in a controlled environment for cultivating crops as this system offers some great advantages. The added benefits of controlling and managing pH, CO2, heat, air movement, nutrients supply, water needs, temperature and lighting, help farmers boost the production of their plants.
  • In a hydroponic, the nutrients are supplied with precision and accuracy, thereby not only lowering the fertilizer requirements per plant but allowing the plants to uptake just what they need for the best performance. Plants don’t have to spend time developing their root systems in search of nutrients as they do in traditional farming, instead, and they can focus on developing their vegetative growth and growing much faster and more efficiently.
  • Growing hydroponically plants improves the quality and taste of products because the system utilizes the quality of nutrients and clean water under a controlled environment without pesticides or herbicides.
  • All of the Watermelon types have similar vine growth characteristics and nutritional, pollination, environmental, and training requirements, with many of the modern, commercial-hybrid types having much more disease resistance than older types. Older melon types are highly prone to mildew diseases, sometimes to the point where many plants are lost long before the fruit reaches maturity, with control difficult even with fungicide sprays.
  • Watermelons are a warm-season crop. Their ideal temperature range is 22 to 32°C, with temperatures of at least 16°C at night required for good fruit set.
  • The Watermelon plants can easily tolerate conditions as high as 33°C. The hybrid melon seed is expensive, so hydroponic growers sow into individual propagation cubes of media such as stone wool to avoid having to transplant.
  • Germination is fastest at 27-30°C, with young plants ready to place into a hydro system within 2 weeks. Many hydro growers make the mistake of keeping larger seedlings such as Watermelons in their propagation trays or cubes for too long.
  • Under ideal conditions, Watermelon plants grow rapidly. The stem will elongate and also needs to be trained upwards within a week of planting out. Watermelons produce tendrils that wrap around strings, other plants, and other objects in their paths, so regular training is required to keep them heading in the desired direction.
  • Sweetness in Watermelons is something hydroponic growers should strive for. Several factors affect sweetness, including cultivar selection, nutrition, leaf area, access to light, and maturity.

In case if you are interested in this: How to Make Money from Hydroponic Store Business.


  1. What are some fertilizers I can use to get my plants grow faster, like watermelon takes 3 months approx for harvest, I need to make it less than 3 month

    What a some nutritional fertilizer I’ll need



Please enter your comment!
Please enter your name here