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How to Grow Tomatoes Under a Grow Light

tomato plants image by Gina Smith from

Tomato enthusiasts can have tomatoes available year-round by producing them under a grow light. It is like stepping into an indoor tomato garden and being able to pick a fresh tomato for a salad or sandwich anytime you choose. You can grow tomatoes indoors, even during the winter months, according to the Colorado State University Extension.

Install two plant grow light tubes in the indoor grow light lamp. Soft white tubes do not provide enough of the blue and red light rays that the plant grow tubes offer for indoor tomato gardening.

Plant starter seeds every two weeks to have tomatoes indoor year-round, advises the Colorado State University Extension. Place the germination pots under a separate grow light to avoid over-crowding the growing area.

Place a small oscillating fan near the tomato plants and grow light. Keep the fan running on the lowest setting whenever the grow light is on. This improves air circulation to reduce the likelihood of tomato blight and encourage better growth rates.

Snip the lower leaves off of the tomato plant with sterile pruning shears, starting from the base of the plant, working your way upward. Remove the lower quarter of the leaves on the stem. Repeat this weekly to retain plant nutrients for the production of flowers and tomato fruit.

Use a different grow light for tomato plants of different heights for the ideal height adjustment of the grow light. For example, place seedlings under one grow light. Place tomato plants with flowers and small tomatoes under a different grow light. Use a third grow light for mature plants.

Shake blooming plants slightly to encourage pollination among the plants, suggests Colorado State University Extension.

Check soil often and add additional water as needed. The grow light increases soil evaporation and plants often need frequent watering.


Keep the grow light 6 to 8 inches above the top of the tallest tomato plant in the growing area.


Leaf burn and excessive soil drying may result from plants too close to the grow light bulbs.

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