Winter does not have to limit your growing of fresh vegetables. With a hydroponic system and adjustable grow lights, you can grow fresh vegetables, including tomatoes, year round. Tomatoes are very easy to grow hydroponically. Many of the winter tomatoes in your local grocer were, in fact, grown hydroponically in commercial hot houses.
Fill the mesh pots in your hydroponic system with rock wool. Rock wool is a biologically neutral growing medium that wicks the water and nutrients up from the hydroponic nutrient solution below the plants.
Plant several tomato seeds in each mesh pot by placing them about 1/4 inch below the surface of the rock wool.
Fill your hydroponic system as recommended with nutrient solution. The bottom 1 or 2 inches of your mesh pots should be submerged in the nutrient solution.
Pour nutrient solution over the rock wool and seeds to make the rock wool wet and place the mesh pots in the hydroponic system.
Cover the seeded pots with plastic wrap to retain moisture and humidity during germination.
Place the seeded pots in the hydroponic system and turn on the power if your system offers nutrient solution aeration. Make sure your mesh pots are submerged by 1 or 2 inches in the nutrient solution.
Remove the plastic wrap when the tomato plants become visible above the rock wool.
Begin turning on the grow lights for 2 or 3 hours a day after the seeds have germinated and formed their first two to four leaves. Set your grow lights 4-6 inches above the seedlings. Increase the height of the lights as the tomato plants grow to maintain this 4-6 inch separation.
Increase the light by 2 hours per day for 5 days until you are giving your plants 12 to 15 hours of light per day.
Change your hydroponic nutrient solution every 2-3 weeks or as indicated on the solution box or bottle.