How to Grow Vegetables in Water Without Soil

How to Grow Vegetables in Water Without Soil

You can easily overcome space constraints and grow vegetables in your home garden through hydroponic gardening — a practice of growing vegetables in water without the use of soil. Roots are submerged in a water-based nutrient solution, while the upper part is supported above the water level. Hydroponically grown vegetables are considered healthier because the process eliminates weeds, bacteria and soil-borne pests. You can use hydroponic systems indoors and grow fresh vegetables year-round.

Start the vegetable plant seeds in an inert growing medium such as rock wool cubes. Place the cubes in a small container filled with 1 inch of water so they remain moist and the seeds sprout successfully. When the seedlings reach a height of 2 to 3 inches and roots start showing through the sides, they are ready for transplantation to the hydroponic container.

Place the hydroponic container where the plants can receive optimum temperature and ventilation. You can also use glass tanks, earthen crocks, metal containers or fibreglass tanks as containers. Most vegetable plants thrive in temperatures between 55 and 70 degrees Fahrenheit.

Cut holes in the lid of the container with scissors. Cut as many holes as the number of seedlings you have, and large enough to facilitate stem expansion. Prepare a platform with chicken wire or hardware wire cloth that fits across the top of the container and covers the holes. Coat the platform with asphalt-based paint.

Add equal parts of nutrient solution and water to the container. You can prepare your own nutrient solution by combining 2 teaspoons of ammonium phosphate, 4 teaspoons of potassium nitrate, 4 1/2 teaspoons of calcium nitrate and 4 teaspoons of magnesium sulphate with 10 gallons of water to form a macronutrient solution. Next, mix 1 1/4 teaspoons of boric acid and 1/10 teaspoon of manganese chloride in 1 quart of water. Add 1/2 cup of this solution to 10 gallons of macronutrient solution. Mix 1/2 teaspoon of chelated iron in 1 quart of water, and use 1 3/5 cup of this solution in the solution for 10 gallons of macronutrient solution.

Test the pH level of this solution with an indicator paper. Most vegetable plants thrive in a slightly acidic solution with a pH of 5.5 to 6.5. Add a few drops of sulfuric acid if the pH level is above 7, and sodium hydroxide if the level is below 5.5.

Clean the roots of the seedlings. Remove the growing medium and rinse any remaining debris from the plants’ roots and stems.

Punch the wire platform at the center of each hole and transplant a seedling into each hole so that the roots remain submerged in the solution. Place 2- or 3-inch wooden chips around the plants on top of the platform.

Pump oxygen into the solution through an aerator to maintain the aeration level in the container. Ensure that the bubbles are spaced 1/2 to 1 inch apart as they rise through the nutrient solution.

Monitor the roots of the vegetable plants as they grow, and adjust the nutrient and oxygen levels based on the growth pattern of your plants.

Things You Will Need

  • Vegetable seeds
  • Rock wool cubes
  • Container with protective lid
  • Scissors
  • Chicken wire or hardware wire cloth
  • Asphalt-based paint
  • Wooden chips
  • Nutrient solution
  • Indicator paper
  • Aerator

Gardening Tips

  • Apply a coat of dark paint on the outer wall of a leak-proof glass container to inhibit algae growth. If you choose metal or concrete containers, paint the inner walls with asphalt paint to prevent corrosion and toxicity.
  • Leave an inch of air space between the solution and the platform for young plants and increase the gap to 2 or 3 inches as they grow.
  • Leave a gap of at least 6 inches between two plants in the hydroponic container. This gives them sufficient space for the roots to expand and feed themselves.