Hydroponic Tomatoes

Hydroponic growing is done in a greenhouse where the growing environment can be controlled. Growers choose tomato varieties that have been bred specifically for hydroponics. Traditionally, soil is the medium that holds moisture, provides nutrients, and offers support for the root system. Hydroponically grown plants have no soil, and therefore no soil borne diseases or pests. Plants are supported in an inert growing medium such as perlite, and nutrients are dissolved in water and delivered to the plants by one of three methods.

In a drip system, the nutrients/water are dripped evenly onto the growing medium to maintain an even moisture level on the root system. The second method is Nutrient Film Technique (NFT), which uses a growing channel for the plants’ roots where a thin film of nutrient material passes over the roots, keeping them moist and fed. The third method is the raft method, in which the plants are floating on a “raft” on the surface of oxygenated water that carries nutrients to the roots in the nutrient solution below.

Photosynthesis is a critical factor in tomato production. Photosynthesis can be disrupted by low light, high humidity, and water stress. A 1% decrease in light translates into a 1% decrease in production. High humidity causes the stomates to close, which reduces the exchange of Oxygen and CO2. Any of these stresses will negatively affect the plant's health, the sweetness of the fruit, the shelf life, and flavor.

Shading from trees or greenhouse framing should be as minimal as possible. Plant rows and greenhouses should be oriented north and south so all plants receive even light. White floors and paint will reflect light back onto plants. In winter in northern climates, you can use artificial lighting in your heated greenhouse to control your tomato environment.