Hydroponic Tomato Gardening

Tomatoes can be grown hydroponically year-round.

Tomatoes can be grown year-round hydroponically, or indoors under lights with water, fertilizers and artificial material like rockwool and heydite. The most common method for growing hydroponic tomatoes is by using a drip irrigation system. According to the Simply Hydroponics and Organics website, the nutritional value of a tomato depends on the nutrition the plant received while growing. By growing hydroponically, gardeners can control the flavor and nutritional value of their plants by providing them with proper growing conditions.

Things You'll Need

• Tomato seeds
• Rockwool starter cubes
• Nursery tray with dome
• Metal halide or fluorescent lighting
• Drip irrigation expando system
• Potassium hydroxide
• Phosphoric acid
• pH soil testing kit
• Pre-mixed nutrient solution
• Small paint brush
• Plastic twine

Instructions

1. Start tomato seeds in 1-inch rockwool starter cubes in a nursery tray. Cover the tray and keep at a temperature of 68 to 77 degrees F. When vegetation appears, uncover the trays and move seedlings immediately to a metal halide or fluorescent light source for 12 hours per day.

2. Transplant seedlings once they have leaves and the roots appear through bottom of the starter cubes after 10 to 14 days. Place the seedlings and rockwool cubes in the drip irrigation system's individual pots. Cover the seedling with heydite, a porous rock mixture.

3. Introduce the plants to the metal halide or fluorescent light source by gradually moving the bulb 1 inch closer every two to three days. When plants are mature, they will require 16 to 18 hours of light and eight hours of complete darkness. Maintain a daytime temperature of 64 to 77 degrees F and a nighttime temperature of 53 to 64 degrees F.

4. Maintain a soil pH of 5.8 to 6.3 by checking the pH level, or level of acidity in the soil with a home test kit. Potassium hydroxide can be added to soil to raise pH, and phosphoric acid will lower pH levels. Fertilize plants with 4 liters of nutrient solution per day and change the nutrient reservoir once a week.

5. Transfer pollen with a small paint brush to the open stigma of each flower over several days when the plant's petals are bent back and the stigma is exposed. Support the plants by using plastic twine to encourage vertical growth and support the fruit. Remove bottom leaves when they become yellow and dry to help air flow and prevent disease.

Tips & Warnings

• The Greenhouse Product News website recommends using beefsteak or heirloom tomato varieties, as they will do well when grown hydroponically.

• If the tips of leaves begin to curl, add water with a pH of 6.0. This may mean the nutrient level is too high.

• If the leaves turn yellow, the pH may be too high. Rinse the root zone with pH balanced water and change nutrient system.

• If flowers fall off before producing fruit, there may be a potassium deficiency. Rinse the root zone and change the nutrient system.

References

• Simply Hydroponics: Home Grown Tomatoes
• Greenhouse Product News: Hydroponic Tomatoes