QA

How Long To Leave Grow Lights On

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! Always position a grow light above the plant.

How many hours per day should grow lights be on?

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.

Can you leave a grow light on too long?

Plants that are exposed to light for too long will produce more energy than they can handle. It could destroy your plant so if you leave them under your grow lights for too long, you’ll just end up with dead and wilted plants. A sign that a plant is absorbing too much light is yellow spots on its leaves.

Can grow lights be on 24 hours a day?

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.

When should I turn my grow lights off?

Leave the grow light on for 16 hours each day. Turn it on in the morning just after sunrise and shut it off 16 hours later. Vegetable seedlings need eight hours of darkness, too. An easy way to accomplish this is to plug the grow light into a programmable timer.

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 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.

How do I know if my seedlings are getting too much light?

Plants exhibit several signs when they’re getting too much light. The most apparent sign is leaf burning. This typically causes the yellowing of leaves at the top of the plant but the veins stay green, and the leaves take on a yellow or brown, burnt look.

How many hours of light do autoflowering plants need?

And since autoflowering plants have short vegetative phases and often grow shorter than photoperiod strains, you’ll typically want to give your autos at least 18 hours of light. This allows for robust growth, without overspending on energy.

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!).

Can plants get too much LED light?

Myth #14: LED Lights Can’t Damage Plants The reality is that modern LED grow lights can produce a very high level of light and it can cause photo-bleaching and burn leaves. This depends very much on the plant, but a PPFD of 800 is enough to damage some plants.

Do plants need a dark period?

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.

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.

Should lights be on during germination?

First, true enough, light isn’t necessary to germinate most seeds: the majority are perfectly capable of germinating in complete darkness. But there is a significant proportion of seeds that will not germinate if they aren’t exposed to light. This includes maybe a third of the plants we commonly grow from seed.

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).

Do seedlings need red or blue light?

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).

What is the best color temperature for grow lights?

As a general recommendation, choose a full spectrum grow light with a color temperature in the blue range (5,000 – 7,000K) to promote vegetative growth and choose a color temperature in the red range (3,500 – 4,500K) to promote fruiting and flowering.

Do you water seedlings everyday?

Seedlings aren’t able to store water for very long, so they need soil that is constantly moist. This means watering them a few times a day, depending on how quickly they dry out. Test your seedling’s soil with the end of a finger to about an inch deep. If the soil is dry, your seedling needs water.

How much light do seedlings need indoors?

How Many Hours Of Lighting Do Seedlings Need? Seedlings need 14-16 hours of light every single day, without fail. Don’t leave them on for 24 hours a day though. Like us, they need to rest at night.

How far should grow lights be from seeds?

The light should be hung so it is 2 to 3 inches above the seedlings and adjusted as the plants grow to maintain that distance for the first month. After that, move lights to 3 to 6 inches above the plants. Keep the lights on for 16 to 18 hours a day until it is time to plant seedlings outdoors.