Best LED Grow Lights for Starting Seeds: A Comprehensive Guide - Peaceful Patch - Gardening for Health (2024)

FAQs

What type of grow light is best for starting seeds? ›

Fluorescent or LED Lights

For most home gardeners, a plug-in shop fluorescent or LED light fixture is the perfect type of light to use for seed starting. When shopping for fluorescent lights, look for high-output, full-spectrum (sometimes called “daylight”) bulbs.

When deciding between T5 and T8 grow lights, it is essential to consider your specific indoor gardening needs. If you have limited space or need targeted lighting, T5 lights may be the better option. On the other hand, if you have a larger growing area or require higher light output, T8 lights are more suitable.

This is why some LEDs give off a purple glow, unlike full spectrum lights that emulate daylight. But as we know, LEDs, like those available for home lighting, come in more neutral white colors that will also work for seed starting.

Basically, gardeners lose 3 inches of light from the ends of each bulb; therefore, a 4-foot bulb is a better choice than two 2-foot bulbs if you're planning to start a lot of transplants under the lights. Seedlings need to be illuminated for approximately 14 to 16 hours per day.

Lights with different wavelengths have varying effects on plants at different developmental stages. Red light promotes seed germination, while Blue light and low Red/Far−Red ratio conditions inhibit seed germination. Both Red and Blue light promote the seedling de−etiolation process.

In the end, both red and blue light are essential for plant growth and development and no plant can survive long-term without one or the other.

When choosing shop lights for seed starting, it is important to look for lights that will provide the right amount of color temperature for plant growth. “Full sun” plants require about 2000-3000 lumens. We have found that alternating between cool and warm lights work best.

If you are looking for the most energy-efficient and brightest option, then T5 LED tubes may be the way to go. However, if you are looking for a more budget-friendly option that is still highly efficient and widely used, then T8 LED tubes are a great choice.

1) Amount of light

Don't worry- you don't need one for this if you're using LED bars or fluorescent bars. Just remember the following distances. LED bars (like Philips): 8-12 inches away from seedlings. T5 fluorescents: 5-6 inches away from seedlings.

According to Pilarchik, any white LED shop lights with a brightness of 5,000 lumens or higher and a color temperature of 5,000 K or higher—like the Hyper Tough shop light—can be used as grow lights for seedlings.

How far should LED grow lights be from seeds? ›

As an unofficial rule of thumb, many growers work on the basis that: You need 20-40 watts of power per square foot. Lower wattage LEDs of around 200 watts should sit between 12-20 inches from the top of the plant. Higher wattage LEDs of 1000 watts and above should sit between 36-46 inches from the top of the plant.

If your grow light has an adjustable intensity, you may need to dim the light down (usually to around 30% intensity). If the light is too intense or can't be dimmed down, it is ideal to place the fixture higher and lower it down as the seedlings get used to the intensity and spectrum.

If you are just using grow lights to start seeds or to grow leafy vegetables, stick to lights that are labeled either as blue-green spectrum or balanced light spectrum. It is increasingly common for lights to be labeled “for greens and seeds” or “for flowers and fruit”.

A: In general, you should not leave grow lights on 24/7. Plants need a light-dark cycle to develop properly. It's believed that they truly do “rest” during periods of darkness, and probably use this time to move nutrients into their extremities while taking a break from growing.

In one experiment, tomato plants were grown under natural light or extended photoperiods of 14, 16, 20 and 24 h. Compared to natural light, extended photoperiod treatments increased shoot fresh weight and yields of tomato plants by, respectively, 40–57% (P<0.05) and 15–20% (P>0.05).

Many seeds do not require any light to shine on the soil to germinate. Even so, I begin turning my grow lights on and off from the first day that I plant my seeds, and I recommend you do the same. Otherwise, make sure you're ready to turn on the lights as soon as you see the first sign of green emerge from the soil.

The presence of light tends to inhibit their growth. The light decomposes carbonic acid gas and expels oxygen which leads the seed to harden. These gases are key factors that promote germination. In dark environments, the gases remain undisturbed and germination is favoured.

Generally, a range of25-50 watts per square foot is considered adequate for most plants in the vegetative stage, while flowering plants may require a higher wattage of40-60 watts per square foot. However, some high-light plants, such as tomatoes and peppers, may require even higher wattage levels.

Seedlings: For seedlings, LED grow lights can be placed about 6-12 inches above the plants. If your grow light has an adjustable intensity, you may need to dim the light down (usually to around 30% intensity).