How To Grow Tomatoes Without Soil - Backyard Boss
We are reader supported. External links may earn us a commission.

How To Grow Tomatoes Without Soil

Tomatoes are a delightful addition to any meal, with their vibrant red hue and savory taste. Luckily, you don’t need a plot of land to enjoy homegrown tomatoes. With convenient methods available, you can relish the goodness of fresh tomatoes right in your own home.

The method of growing plants without soil is known as hydroponics. In this method, the plant roots are submerged in water and utilize the mineral nutrients in the water to flourish. Soft-tissue plants that grow above the ground, such as tomatoes, are quite popular to grow this way. So, without further ado, learn how to grow these vibrant, fresh fruits without any soil.

Materials You Need 


Here is everything you will need to grow beautiful tomatoes without any soil.

  • Tomato seeds or seedlings
  • Plant starter cube
  • Reservoir tank
  • Reservoir lid
  • Drill machine
  • Protective gear, such as gloves and goggles
  • Air pump and air stone
  • Net hydroponic pots
  • Fertilizer 
  • Water 

Step 1 – Prepare the Reservoir


There are different hydroponic systems available to grow crops commercially. However, the simplest system, ideal for growing tomatoes at home, is the Deep Water Culture (DWC). This system works well for home gardeners since it is easy to assemble and maintain. While you can buy a DWC system, it is cheaper to DIY it at home

To create a DIY hydroponic system, take a bucket or a plastic storage container with a 5-gallon capacity, which will function as your water reservoir. If using plastic, ensure the reservoir is clean and made from food-safe materials such as polypropylene.

Additionally, it should be opaque to prevent light penetration that can lead to algae growth in the growing medium, i.e., water.

Next, make a hole at the bottom of one side of the container using a drill machine. Remember to put on your safety gear to avoid any accidents. Place an air pump tube at the hole and attach it to the reservoir to circulate oxygen into the water.

Step 2 – Prepare the Lid


While the reservoir holds the nutrient-rich water, the lid supports the tomato plants, so the foliage stays above water, and only the roots are submerged. If your container has a lid, you can use that as a support structure. Alternatively, you can use polystyrene to help the plants float. 

Make holes in the lid that are large enough to fit the net pots. Space the holes 18 to 24 inches apart to give your tomato plant ample room to thrive.  

Step 3 – Start the Seeds


To grow tomatoes from seeds, start the seeds separately and transplant the seedlings into the hydroponic system. There are two ways to germinate seeds.

Using Starter Cubes

Starter cubes or grow plugs are used to germinate seeds without soil. They are made up of coconut coir or rock wool. 

To use the cubes, soak them in water and add the seeds. Place them partially submerged in water to trigger the seed to sprout. Once roots appear through the bottom of the cubes, the seedlings are ready for transplanting.

Since there are different types of starter cubes, read the instructions on the packaging to determine the correct way to use them.  

Using Soilless Mix

Fill a seed tray or small pots with a moist soilless starting mix and plant about two seeds per section. Cover them lightly with more starter mix. Place the seed tray or pots on a sunny windowsill to give the seeds the warmth they need to germinate. You can also place them over a heat mat.

Water the seeds on alternate days until they sprout. The best way to hydrate the plant is to place it on a water-filled tray and allow the starter mix to soak it up. Your seedlings will be germinated in about 10 to 14 days.     

Step 4 – Prepare Water


While your seeds germinate, you need to mix nutrients into the water. Tomatoes require relatively high levels of potassium and phosphorous and a pH between 5.5 and 6.5. The plant also requires calcium for the creation of fruits. 

You can purchase a nutrient solution designed for hydroponics online or from your local garden store. Check the labels to ensure it fulfills the specifics required for growing tomatoes and for measurements. Test the prepared water’s pH after adding the nutrients to ensure it lies within the ideal limit. 

Step 5 – Place the Seedlings in Water


You can place the seedlings in starter cubes directly in the net pots along with the cubes. For seedlings grown in soil gently rinse the soil from the seedling roots with room-temperature water before placing them in the net pots/hydroponic system. 

Put the pots in the holes cut out in the lid, submerging about half the pot in the water so just the roots are below water level. 

Step 6 – Care for the Plant


Tomatoes require warmth and light to produce fruit. Expose your plant to at least seven hours of sunlight daily and keep the daytime temperature between 65 and 75 degrees Fahrenheit, with the nighttime temperature between 55 and 60 degrees Fahrenheit. Add a trellis or support stake for each stem to prevent the plant from breaking under the weight of the fruit. 

Keep replenishing the water in the reservoir as the level drops due to evaporation or absorption by the roots. Every time you add water, add more nutrients according to the recommendations on the label and check the pH regularly. 

Pro Tip: Make sure to change the water often otherwise, the water can succumb to algae and bacterial growth, detrimental to your plant’s health. 

No Soil, No Problem

Growing plants hydroponically is a great way to compensate for the lack of garden space. It is also intriguing to see your plants thrive without any soil. While the method differs from the usual gardening method, it is not very difficult. You can also buy a pre-made hydroponic system and tomato seedlings to cut down the steps!

Have you tried growing tomatoes without soil? Share below in the comments!

shares