For most of us, it seems like winter is never going to end. Weekly, I am checking the backs of my seed packets in anticipation of the upcoming growing season. Planning out which beds will house plants, dreaming of a yard filled with veggie gardens and full-color planting beds... does this sound familiar?

If it does, then you should consider a grow light! With artificial light, you can actively grow in a greenhouse or indoors all winter or get a great jump-start on spring. Grow lights are especially important if you live in a particularly cloudy area or if you have exceptionally short days (most plants like about twelve hours of light). Without sufficient light, plants are not able to adequately photosynthesize, and they will not mature properly.

Supplementing your natural light with a grow light will provide an extra boost to your established plants too. Last year we wintered over two identical plants in our greenhouse; one under a grow light and one not. The plant under the grow light was 30% larger by spring. Once outside for the summer, the smaller plant never caught up!

There are several types of grow lights available, each providing specialized types of light to benefit your plants at different stages of growth.

Fluorescent Lamps

The most common grow lights used for starting seeds are fluorescent lights. They provide full-spectrum light, so they closely match the light from the sun. Since they give off very little heat, you can put them close to your plants so the plants get as much light as possible. Plus they are very efficient and don’t use a lot of energy so you save money on electricity.

 

T5 Fluorescent Lighting

/high-output-fixture-light-p-374.html" class="style6">T-5 lights. T5 fluorescent technology is changing the way gardeners’ grow. With T-5 lights, gardeners are now reaping a huge benefit - more light intensity to their plants while using less energy. For example, a typical 54 watt high output (HO) T5 bulb produces 5,000 lumens, compared to a 40 watt T12 which will produce 1200 lumens. Most grow light systems that utilize T5 technology will use a combination of 2, 4, or 6 lights to maximize the lumen output. Just one of these bulbs gives you an output of 93 lumens per watt. To put this even more into perspective for you, a regular incandescent 100w light bulb only provides 1260 total lumens, or 12.6 lumens per watt.

Another benefit is size - T5 bulbs are extremely thin. This slim profile makes T5 fluorescent bulbs more efficient than standard fluorescent tubes, and offers additional benefits including longer lamp life, power efficiency, and extremely high lumen output per watt.

T5 lighting is excellent for starting seeds and cuttings, but also produces enough light for full-term growth. This means no switching bulbs half-way through your plant’s growth cycle to accommodate the needs of what you are growing, which in turn means less work for you. And because of their minimal heat output, T5 lights can be placed very close to the plant canopy – just 6-12” to maximize the light output.

Metal Halide Lighting

Metal Halide, one of the two types of High Intensity Discharge (HID) lighting used for plant growth, works by emitting a blue/violet color spectrum. This spectrum of lighting stimulates vegetative growth and is a good light for starting seeds and cuttings. This is the best type of light to use as a primary light source, where you have little or no natural sunlight available (such as indoors). Metal Halide also works well if for growing leafy plants such as lettuce or herbs. A big advantage to using HID lighting is that you can cover a large area. One 400 wattlamp will cover a 4’ x 4’ space and provide secondary lighting to a whole 8’ x 8’ area. This means you can cover a broader area with fewer fixtures. The downfall is that HID lights emit heat so they need to stay a few feet away from your plants to avoid burning. Because of this, your plants won’t get as intense of light as they will get with Fluorescent lights.

Metal halide lighting is very efficient. A standard 400 watt metal halide bulb will produce approximately 32,000 lumens, or 80 lumens per watt. With an ‘on’ life of 20,000 hours you have a fixture that will last you for quite a while.

High Pressure Sodium Lighting

/watt-sodium-replacement-bulb-p-37.html" class="style6">sodium bulb, at 400 watts, provides approximately 42,000 lumens, or 105 lumens per watt.

Convertible Fixtures

An easy way to blend both halide and sodium lighting is by using a convertible fixture. This type of fixture houses both a halide and a sodium bulb. One of these fixtures allows you to specifically target the type of growth your plants need, and eliminates the need to purchase two separate systems.

Don't forget that you are simulating nature, so your plants will need periods of darkness too. Most plants and vegetables thrive on about 10 - 12 hours of light, which promotes growth. Flowering or fruiting plants can use up to 16 hours of supplemental light per day, which still leaves 8 hours to rest in the dark.