Many plants only reach maturity or produce a decent harvest if they are given a head start on the growing season. This is done by starting the seeds indoors or inside a greenhouse. Although you can attempt to depend on natural sunlight via windows for growing healthy seedlings, horticultural lighting systems are a much better option.
In many areas, winter and early spring still mean cloudy days and minimal sunlight, so even an all-window greenhouse may not provide enough light to get seedlings to a healthy start. By using growing lights, you bring the sun to your seedlings no matter the season or location. This way you can give them a few weeks extra to grow into more robust plants.
A problem with seedlings is their propensity to grow leggy. Leggy plants have weak, overly long stems, which are caused by trying to reach toward a light source -- such as when plants lean towards a bright window. Even lighting from all sides prevents legginess and leads to stockier and healthier growth. Horticultural lights can be equipped with deflectors to further help even light exposure.
Plants require exposure from much of the light spectrum, but mainly from the red and blue range of the spectrum. Normal indoor lighting may not produce the full spectrum that plants require. This is especially true for residential LED bulbs. LED horticultural growing lights, on the other hand, provide the full spectrum of light that plants need so you end up with healthier seedlings.
Regular light fixtures, especially those still using incandescent lighting, will produce too much heat close to sensitive new seedling leaves. Even fluorescent residential bulbs and grow lights can produce a bit too much heat for seedlings. If you opt for LED lights, then there will be nearly no additional heat produced. This makes it easier to accurately control temperature via normal environmental settings.
Well-lit seedlings are more likely to grow with a healthy form, which means more will grow to maturity. Furthermore, good lighting can help prevent conditions where seedling pathogens, such as fungus and bacteria, thrive. Fewer disease pathogens mean more seedlings reaching a robust and productive maturity. Proper lighting can also ensure more seeds germinate if the seeds are light sensitive.
If you plan to start seeds indoors or in a greenhouse, then a horticultural lighting system is the secret to success. Click here for more info about commercial LED growing lights.