How to Grow & Prune Hydroponic Tomatoes


Hydroponic tomatoes grow similarly to garden tomatoes. However, with hydroponic tomatoes gardeners have more control over the amount of nutrients introduced to the plants; the plants produce fresh fruit year-round; and the plants have a reduced chance of insect and disease damage. A hydroponic system requires regular monitoring to maintain the proper pH and nutrient levels. It also requires pruning to increase fruit production and plant health.

Grow Tomatoes

Step 1

Rinse all soil from the roots of tomato seedlings and plant them in netted pots or rockwool cubes. Space the plants at least 10 inches apart to prevent crowding.

Step 2

Test the water pH in the hydroponics system, as tomato plants grow best in a pH of 5.8 to 6.3. Tomato plants have a decrease in nutrient absorption when the pH is too acidic or alkaline. Adjust the pH by adding potassium hydroxide to increase the pH number or phosphoric acid to decrease the pH number.

Step 3

Add hydroponics nutrients to the water supply based on the package instructions and the quantity of water pumping through the system. Add more nutrients when refreshing the water to maintain an adequate level for plant growth.

Step 4

Place the hydroponics system under grow lights turned on for at least 16 hours each day to stimulate blossom and fruit production. Metal halide lights produce good results with tomato plants.

Prune Tomatoes

Step 1

Clip or pinch off blossoms that form while the tomato plant branches and foliage are still growing. Leave blossoms on that form once the plant reaches a mature size.

Step 2

Remove lateral shoots as they form on the tomato plants. These shoots are small branches that form on the main stem between two fruit producing stems and cause the plant to become leggy and not as productive.

Step 3

Clip or pinch off sucker leaves as soon as they form under the lowest cluster of blossoms. Suckers are small leaves growing in the joints of main stems. The leaves will continue to grow into non-fruiting branches and reduce the amount of fruit produced on the plant.

Step 4

Remove leaves that dry or turn yellow by pulling them off with your hand or cutting with a pruning clipper.

Things You'll Need

  • Rockwool cubes
  • Netted pots
  • Hydroponics growing system
  • Water pH test
  • Potassium hydroxide
  • Phosphoric acid
  • Hydroponic nutrient mix
  • Metal halide lighting system
  • Pruning clipper


  • University of Arizona: Growing Tomatoes Hydroponically
  • Hydroponic Garden Growing: Hydroponic Tomato Gardening
  • Fine Gardening: Pruning Tomatoes
Keywords: grow hydroponics tomatoes, prune hydroponics tomatoes, plant hydroponics tomatoes

About this Author

Jennifer Loucks has over 10 years of experience as a former technical writer for a software development company in Wisconsin. Her writing experience includes creating software documentation and help documents for clients and staff along with training curriculum. Loucks holds a Bachelor of Science major from the University of Wisconsin - River Falls specializing in animal science and business.