QA

Question: How To Use Grow Lights

How many hours a day should you use a grow light?

To be effective, grow lights really need to be on for at least 8-10 hours a day. This can vary up to 16 hours, depending on the conditions. That’s why LED grow lights are so popular – when they have to be left on all day, it’s best to use an energy efficient type!.

What is the best time to turn on grow lights?

To play it safe, you could turn on the light a few days after you plant seeds, even if they haven’t popped up yet. Once sprouted, most vegetable seedlings and other garden plants require at least 12 hours of good light per day, along with 8 hours of darkness.

How long should I leave grow lights on?

Some gardeners like to leave their lights on for 24 hours to get maximum growth. However, by far the most popular light duration for vegetative plants is 18 hours on and 6 hours off. This schedule will mimic a day of full sunshine followed by a natural dark period.

How long to leave grow lights on for indoor plants?

Plants grown indoors require more hours of light than those grown outdoors. 14 to 18 hours of light per day is recommended for most edible species when grown under artificial lighting. Don’t be tempted to leave the lights on 24-7, however – at least six hours of darkness each day is essential to plant health.

Should I turn off the grow light at night?

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.

What color grow light is best?

Blue light has the best absorption by the plant due to the green pigment every plant has, also known as chlorophyll. This chlorophyll absorbs the blue light and transfers it into energy through photosynthesis making the plant grow faster because it’s able to get more nutrients.

How long do you leave grow lights on seedlings?

Keep the lights as close to the seedlings as possible without touching them (2 to 3 inches). When seedlings first appear, keep the lights turned on for 12 to 16 hours per day. To reduce your hands-on time, use a timer to turn the lights on and off automatically.

How many hours a day should seedlings be under a grow light?

In general, seedlings should receive roughly 14 to 16 hours of light a day when situated in a south-facing window. This can be very difficult to achieve, and most growers opt to use artificial lights for their seedlings. These fluorescent lights should be left on for 12 to 16 hours a day.

What color light is best for seedlings?

Light Color Red light stimulates vegetative growth and flowering (but if a plant gets too much, it will become tall and spindly). Blue light regulates plant growth, which makes it ideal for growing foliage plants and short, stocky seedlings (but too much will result in stunted plants).

Where should grow lights be placed?

In general, you’ll want to hang your light no more than 12″ away from your plants. – Remember: after 12″ fluorescent lighting loses its power, so make sure you don’t raise it any more than 12″ above your canopy otherwise your plants aren’t getting light energy.

Can LED grow lights burn plants?

While LED lights do produce some heat, they deal with that heat more effectively than other light types. Plants can grow much closer to LEDs than other lighting types because of this. Usually crops can grow right up to the light without burning.

Do plants need dark periods?

Plants do need that period of darkness for their metabolism to work properly. They are not designed to create food non-stop, and it will do them harm in the long term to put them in this sort of situation. So, yes, plants need their darkness just as much as they need their light.

How much light do I need for my grow room?

Standard advice says you should aim for 32-50 watts per square foot of grow space. More like 25 watts if your grow space is a dedicated veg tent. So if you were working with a 3′ x 3′ space, you’d theoretically want an LED light with a power draw somewhere between 225 watts (vegetative) and 450 watts (flowering).

Are grow lights considered indirect sunlight?

Artificial Light Intensity. Grow lights are sometimes a better choice for providing proper light intensity, especially when growing plants that require intense lighting indoors. Although outdoor sunlight is intense, sunlight filtered through a window isn’t as intense, and it is often indirect for much of the day.

Can you give your plants too much light?

To put it bluntly, yes, too much light can eventually kill your plant. The light intensity can produces increasingly severe damage to your plant to the point where it dies. It can also dry out the plant to the point where it no longer has the water it needs for growth and photosynthesis.

How do you know if your plant is getting too much light?

If your plant is not getting enough light, the most common sign is the yellowing and dropping of leaves, stunted leaf growth, elongated stems, and a dull-green color. If your plant is getting too much light, then its leaves will have singed tips, burned patches, or will be falling off (yikes!).

Why are grow lights pink?

Pink LED fixtures usually contain red and white LEDs, creating a less purplish, whiter light than purple LED fixtures. These fixtures are usually slightly less efficient than purple LED fixtures because white LEDs are slightly less efficient than blue LEDs. However, the spectrum is more pleasing to the eye.

What does blue light do for plants?

Generally, blue light suppresses extension growth; plants grown with blue light are usually shorter and have smaller, thicker and darker green leaves compared to plants grown without blue light (Figure 1).

Are purple grow lights better?

The Benefits of Purple Light This is great for plants because it provides exactly what the plants need to grow and thrive, and it avoids giving them excess light that they’ll waste. The ratio of red to blue diodes in a grow light will also benefit your plants.