Using Grow Lights to Start Seedlings!

Grow lights are an essential gardening tool when starting seeds indoors during the last part of winter and early spring. The sun’s rays are not strong enough in the Northern Hemisphere to allow seeds to germinate and grow inside.

Seeds require light to germinate and put forth stems and leaves. Properly installed and used lights enable seeds to develop into strong plants that are planted outside at the earliest time in order to capitalize on the growing season.

Once the seed germinates and breaks through the seed casing, the stem and leaf pushes up through the soil. Once it gets there, the energy has been depleted and it needs a source of energy, which is the sun or light. If they do not receive enough light, they remain weak and are susceptible to fungi and other diseases.

Indoors, it is hard to find a place where seedlings get enough light to create more energy unless you have a greenhouse. Grow lights are essential especially for vegetables that need intense light.

grow lights seedlings

Choosing the right light for the plants you intend to grow is very important. You do not have to purchase a light labeled as a “grow light”. They can be very expensive. A fluorescent light does the job just as well and even produces some heat for the seeds to soak in. Three things should be kept in mind when choosing a light to use to grow seedlings. They are: Intensity of the light, duration of the light and color of the light.


A seedling that does not receive the right intensity of light can either wilt or keel over and become limp and lifeless or they can grow tall and leggy because they are reaching very hard for the light. The intensity of a grow light or fluorescent light is controlled in two different ways. The first is by how close the light sits to the seedlings and the other is the wattage of the light.

Placing fluorescent bulbs about 2 to 3 inches above the foliage of the seedlings is safe because these types of lights do not create extreme heat. If using a grow light, read the instructions as to how far away the light must be from the plants you are growing so the foliage does not start to burn.

Another nice thing about using fluorescent lights that are encased in a metal casing is that flats can be placed on top of the lights for those plants that need bottom heat, like many herbs, in order to germinate.

Once they sprout, take them off and place them below the lights. Once a week the fluorescent lights should be moved up to a 3 or 4-inch distance from the foliage of the plants. The best way to do this is to use metal shelving fitted with a long chain on which the fluorescent lights hang. Just move the light up the chain as the plants grow.

Duration of Light.

Vegetables may require anywhere from 14 to 18 hours of light per day. Don’t just leave the lights on all day and all night though because resting time is very important to the plants too. They need about 8 hours of darkness during a 24-hour period. Use an automatic timer that will turn the lights on and off so you don’t have to worry about it yourself.

Color of the Light.

grow lights

Color does make quite a difference in the growth of plants. The light should closely resemble the sun and fluorescent bulbs that are “cool-white” are the best for the job. Yellow or blue tinged lights do not look like the sun and the plants will not grow as well nor will they adapt to the actual sunlight once taken outside as easily.

When it comes to growing full-grown plants under grow lights, the orange or reddish toned lights are good for flowers while blue or green is better for foliage plants. When it comes to starting seedlings, it doesn’t really matter and cool-white fluorescent bulbs work well. Warm-white bulbs do not give off sun-like light.

Some may ask what the difference is between real grow lights and fluorescent lights. The answers include price and the look of the light. Fluorescent lights are much cheaper and grow lights look better.

When using light to grow seedlings, it really doesn’t matter much which you use and, in fact, fluorescents may be the better choice. If lights will be used indoors for full-grown plants, then grow lights fit the bill much better because they are more aesthetically pleasing to the eye. Grow lights often cannot be moved up or down to accommodate the needs of seedlings.