LED grow lights are becoming a popular choice for indoor gardeners. Originally created for space station use, they are more efficient and last longer than traditional metal halide and fluorescent lighting used for hydroponics. They are also more expensive, but if you need to grow tomatoes indoors due to limited lighting or outdoor space, they can be worth the cost in the long run.
Determine what type of LED light you will need for the space you have to grow plants. Some lights can hang on a suspended rack; others are on stands, like a lamp; still others are modular units that can be attached to something already in your house.
Lay the plastic tarp or tub on the floor where you plan to have your indoor garden.
Fill seedling or peat pots two-thirds of the way with potting soil. Add a small amount (such as a tablespoon) of the organic fertiliser and mix into the dirt with a gloved finger.
Press two tomato seeds or one seedling gently into the dirt. Cover the seeds or seedling with more potting soil.
Place the pot in the seedling tray, or directly on the tarp or in the tub. Repeat with remaining pots.
Water the soil so that it is lightly saturated, but not so much that water is pouring out of the bottom of the seedling pots.
Position the chosen LED lights over the seedling plants. If you are using the tub, attach the LED lights directly to the inside of the lid. Place the lid at a slight angle over the rim of the container, allowing air to flow while the plants still get plenty of lighting.
LED lights come in different sizes; choose the size that best benefits the area where you will be growing tomatoes. As the plants grow, you will need to transfer them to larger pots and reposition the LED lights to the plants' height.
Keep soil moist to optimise plant growth. Most potting soils have plant nutrients included; using a commercial fertiliser could "burn" seedlings with too much of a particular nutrient.