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What kind of grow light is best for seedlings?

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hydroponics led grow lights ECO Farm

Using seed starting lights during the winter can make sure your seedlings get the enough light they need to be grow as strong and healthy. Find out how to choose the best grow lights for seedlings!

Was your recent attempt to grow seedlings did not go as you hoped?

If you experienced having leggy and weak sprouts after germinating your seeds, then the problem is most likely the light they received right after the moment they surfaced.

Now, you might be wondering do you really need a grow light to start seeds indoors?

A direct and simple answer is, seedlings need more light than full-grown plants, It’s ideal for seedlings to get as much as 14 to 16 hours or at least 8 hours of exposure to light in a day and that is actually more than a whole day of sunlight.

Types of grow lights

You can choose between fluorescent, LED, and high-intensity discharge (HID) bulbs, each of which has its own pros and cons. Choose the grow light that works best for the type of plants you want to grow and where you plan to grow your seeds.

Fluorescent

These types of bulbs produce two to three times more light than incandescent bulbs for the same amount of energy and are the most inexpensive lights for indoor gardening. However, they usually require bulky external ballasts (like, for example, overhead shop lights) so aren't as easy to work with as incandescent and LED bulbs.

Cool white bulbs are a good source of blue and yellow-green light, but are a poor source of red light. Plants grown under cool white bulbs will be stocky or even slightly stunted. Warm white bulbs emit plenty of orange and red light, but less light in the blue and green spectrum. These bulbs, when used alone, result in tall, spindly plants. If you are growing seedlings under two-bulb fluorescent fixtures, you can usually achieve a good color balance by combining one cool white and one warm white bulb.

Full-spectrum fluorescent bulbs produce a balance of cool and warm light that replicates the natural solar spectrum, although these are less energy efficient than other fluorescent bulbs and tend to produce more heat. But, given the wider range of light frequencies emitted by these bulbs, they are a good choice for growing seedlings.

T5 lamps are fluorescent lamps that are 5/8" of an inch in diameter, making them much less bulky than typical fluorescent bulbs. These are the lamps you're most likely to find in grow light kits.

When using fluorescent lamps, be sure that all plants get ample light. For a typical seedling tray, that means using 2 bulbs, ideally with a reflector hood over them to focus all the light on the seedlings below.

LED grow lights

Unlike other bulbs which produce light across a broad spectrum, light-emitting diodes (LEDs) give off light within a narrow band. LEDs designed for growing plants emit light in the two bands that plants need - red and blue. The result is a purple glow that not everyone likes.

Full spectrum LED grow light provides plants in all stages from veg to flower with everything they need in the natural sunlight.

LEDs are mercury-free and won't shatter like glass. These bulbs are long-lived (up to 5x longer than fluorescent lamps) and very energy efficient, but they cost considerably more than fluorescent bulbs.

Research is still ongoing to determine which combination of light frequencies are best for plant growth and how LED grow lights compare to fluorescent bulbs in producing healthy seedlings. I haven't seen a definitive answer on this one yet but more and more companies are producing LED grow lights for seedlings, and even commercial growers are slowly moving in that direction.

High-Intensity discharge grow light

These lamps are used by commercial growers and serious horticulturists. These energy-efficient bulbs generally emit twice the amount of light (lumens) as a fluorescent bulb. However, the bulbs and special fixtures are considerably more expensive than those needed for incandescent or fluorescent lights. They also tend to be high-wattage bulbs, so you need to be sure your electrical system can handle the load. Some of these lights burn so brightly that they must be located in a special room and you’ll need to wear eye protection when working around them.

Metal halide lights emit an intense, bluish-white light that is excellent for growing plants. The foliage stays green and vigorous, and plants are usually stocky and strong. Metal-halide lights are currently the number one choice for serious indoor gardeners. Mercury vapor lamps emit a bluish, relatively well-balanced, high-intensity light. High-pressure sodium bulbs are usually used to promote flowering and fruiting but, when used exclusively, they produce leggy, weak-stemmed plants.

Which is the best grow light for your seedings?

Seedlings are in the most delicate stage of growth and deserve the best support you can provide to them. There are a few things you may want to consider before you make a purchase to ensure you get both what you are comfortable with, and what your plants need.

How much space is your grow?

Every light has its own footprint within which the whole plant receives the full wavelength of light being offered. Types of lights, sizes, and strengths of each determine this, so you will want o make sure you are covering the entire space within which you are placing your seedlings.

What plants do you need to support?

Do a little research about the types of plants you are trying to get started. Most prefer high levels of blue wavelengths as seedlings but may also benefit from additional sources of light as they grow. This is especially true of tropical and hybrids plants.

Will you need your light for other purposes?

If you are looking for a light to support more than just seedling starting and growth, and also would like to support bloom and production, you may want to consider a full spectrum choice. These allow you to grow a season’s worth of produce all within the comfort of the indoors. This is nice for a fresh taste through the winter, or if you live in an area with a short growing season.

Growing Tips

  • Rotate your plants each week. The light from a fluorescent bulb is more intense at the center of the bulb than it is at the ends.
  • Replace fluorescent tubes when the ends darken. That means the tube is old and the light output may be less than half of a new bulb.
  • Clean your fluorescent bulbs each month. Dust and dirt can dramatically decrease the amount of light emitted.
  • Place your hand where the light hits the foliage. If you feel any warmth, the light is too close.
  • Move the lamp upward as the seedlings grow; you want to keep the lights about 2-4 inches above the plants.

Why would I want a grow light for seedings?

Seedlings need both even lighting and proper temperatures to ensure vigorous, strong growth. Spring months are often unpredictable. Your home may have varying degrees of sunlight and temperatures that can affect growth rates of plants. One trick is to keep your seeds facing the window so they get the length of daylight they need.

With a grow light you can grow anywhere without worry of seasonal changes or window placements. You also can set up a room, or a marijuana grow tent to support your seedlings as they grow- and deter your pets (or children) from making a mess of your young plants.

What spectrums of light do seedings need?

The light spectrum is made up of visible and non-visible colors of light that emit various wavelengths measured by the temperature they provide. As mentioned, blue light wavelengths are utilized best by growing and maturing plants in vegetative stages of growth, and there are many lights available that are more specific to this side of the spectrum.

Of course, all stages of growth can benefit from a full spectrum exposure but be aware of young, maturing plants. They will use more blue wavelengths than others. They crave longer exposure to lights, so when choosing a grow light, be sure to pick one that will run for up to 18 hours a day without overheating or burning out.

Final thoughts

For the average home gardener starting seedlings indoors, a fluorescent or LED lamp will usually be the best choice to ensure that your plants get the quality, intensity, and duration of light they need to stay in peak condition.

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