Hydroponics for Tomato Plants

Tomatoes fare well with hydroponic growing techniques.

It's possible to grow one of the classics of the veggie patch, the tomato, without the need for any soil. Hydroponics, the science of growing plants in nutrient solutions, applies well to the tomato plant, having been tested in horticultural laboratories and working farms around the world. If you're looking for an interesting science experiment or an alternative approach to your tomato growing, try cultivating the juicy fruits hydroponically.

Media

While hydroponics is well known for substituting soil with water-based solutions, there are actually a range of media available to deliver nutrients and provide root systems with physical support. In deep flow systems, roots hang downward into nutrient solutions, floating on plastic or foam supports. In aeroponics, nutrients are sprayed into closed chambers that contain the plants' roots. Finally, in aggregate hydroponics, materials such as perlite, rockwool, peat or coir substitute for soil. The porous, solid materials provide support for root systems while letting nutrient solutions filter through.

Planting

To propagate tomato seeds, soak them thoroughly and set them in a peat, perlite or rockwool-based medium. Should you use a nutrient-rich starting medium, the new seedlings may not require additional nutrient solution for their first few weeks of growth. Sow the seeds 1/4 to 3/8 inches deep in the medium. If the seeds are not in direct sun, you can cover them with a sheet of plastic. Remove the plastic as soon as the first sprouts appear. Transplant the seedlings into their final medium around 12 to 14 days after first sprouting, well before they first flower.

Environmental Conditions

For best results, your hydroponic tomatoes should have an air temperature between 70 and 80 degrees Fahrenheit by day and between 60 and 65 degrees Fahrenheit at night. For tomatoes grown inside a greenhouse, provide ample air circulation, as well, whether with fans or a convection system of vents. The humidity should be between 65 and 75 percent at night and between 80 and 90 percent by day. Higher humidity can reduce tomato yield and even stunt flower or fruit production.

Calendar

The ideal planting calendar for hydroponic tomatoes varies widely by region. In general, you can expect to harvest tomatoes 85 to 100 days after planting seeds. Tailor your planting dates according to your local climate, providing a window of appropriate temperatures lasting at least 100 days. You can transplant seeds from a greenhouse to an outdoor area 10 to 30 days after planting seeds. Depending on your climate, a single growing season may accommodate one or two crop rotations. For example, a two-crop rotation could take advantage of a greenhouse to plant tomatoes earlier in the spring, planting the second round to ripen in early fall.

References

• University of Arizona: Propagation
• Texas A&M University: Greenhouse Tomato Culture
• University of Arizona: Environmental Control Systems
• University of Arizona: Growing Media