Hydroponic vegetables grow in a controlled environment using a mixture of liquid nutrients and no soil. Although a small herb growing hydroponic system fits on your countertop, greenhouses provide the most common environment for growing hydroponic vegetables. When growing vegetables hydroponically, choose ones your family enjoys eating. Hydroponically grown vegetables produce crops faster than traditional gardens, and because of their protected environment offer fresh produce outside of the normal growing season.
Start hydroponic lettuce from seed using flats or individual containers. Select either leaf lettuce or semi-headed lettuce varieties. Good choices are Boston, Black-seeded Simpson, bibb or buttercrunch leaf lettuce. Even in a greenhouse, your lettuce requires additional light to grow successfully. You can use LED, metal halide, high pressure sodium or fluorescent lights. Place the grow light at the manufacturer’s recommended height over the hydroponically-growing lettuce based on lumens and heat generation. Lettuce prefers cooler ambient temperatures than warm weather crops. Therefore, set your temperature controls for 75 degrees Fahrenheit during the daytime and 55 degrees Fahrenheit at night.
Start hydroponic tomatoes from transplants rather than seeds for ease in controlling required growing conditions. Roads and Bridges magazine recommends trying indeterminate, disease resistant varieties such as trust or Daniela. Good cocktail or cherry tomato varieties for hydroponic growing are cherita and sweet 100s. Productive heirloom cultivars include Moskvich and Thessaloniki.
Hydroponic tomatoes require staking or other support systems to maintain the plant in an upright position. Tomatoes need flowing nutrient systems where the feeding solution moves past the roots on a schedule four to six times per day. For seedlings, set the temperatures between, 68 degrees and 72 degrees Fahrenheit suggests the University of Arizona. Gradually increase the daytime temperature 70-79 degrees Fahrenheit and decrease the nighttime temperature to 61-65 degrees Fahrenheit. Use supplemental lighting up to 18 hours per day to improve production. Pollinate through vibration or gently shaking stems with blossoms.
Peppers, like tomatoes, prefer warm growing conditions. Most peppers plants also require staking according to Dr. Howard Resh of Better Buy Hydroponics. Suggested varieties to grow hydroponically include cubico, mazurka, Fellini, Narobi and gold flame for sweet peppers and jalapeno, habanero and cayenne for hot peppers.
Light and temperature requirements to grow peppers hydroponically remain the same as growing hydroponic tomatoes. However, raising nighttime temperatures and slightly decreasing daytime temperatures with up to six irrigation cycles per day improves fruit production after plants reach their mature height.