Grow lights vs. sun

[enchant]

I planted my seeds in cells in a hydration dome, and once they sprouted, I moved them out of the dome and under grow lights (about 16 hrs on, 8 hrs dark). Now that they've starting to get 3-4" tall, I'm repotting them and putting them in our family room, where they get a lot of direct sunlight.

Is sunlight always better than grow lights? Is it too intense for infant seedlings? On a cloudy day, is the subdued natural light coming in through the window as good as grow lights?

I'm just wondering when is the best time to migrate the seedlings from the grow light to the natural light.

[KarenO]

sunlight through a window is not the same as sunlight outdoors at all as much of the full spectrum of sunlight is filtered out coming through glass, especially if the windows are modern. Window light plus artificial light is a good combination and I set my grow lights up on a shelf unit in front of a very large south facing window. It's may now though so time to get seedlings used to real light by getting outdoors into progressively brighter sheltered areas for progressively longer periods of time. This is called hardening off, the process of acclimating indoor grown plants to the bright sun outdoors along with wind and temperature fluctuations. The brightest indoor light is far inferior to natural outdoor light, even on a cloudy day and even the best and most expensive grow lights can't begin to replicate the full spectrum of natural sunlight.
KarenO

[RayR]

Karen speaks the truth, get them outside for hardening off.
It's time to get your babies acclimated to the real world, plant out time is only weeks away.

[enchant]

Last year, I neglected hardening and lost all my cukes. I'll start bringing them outside to play.

[clkeiper]

Originally Posted by enchant

Last year, I neglected hardening and lost all my cukes. I'll start bringing them outside to play.

When you plant your cucurbits up plant them in their cups (or whatever you use) outside in a sheltered spot. I plant my seeds about 5 days before I want to put them in the ground. I never plant with more than two leaves emerged. After that they are getting rootbound and don't produce very well after they are planted. The other method of planting I use is to either cover the whole row with row cover ( I plant a lot for farmers markets) or place a little pile of shredded paper over each plant to shield it from the sun for a few days.

[GreenFarmer]

i found that higher intensity indoor light hardens them up faster easier when moved outside. near a window is not enough sun

[Tapout]

My grow light set up is by a window where I get sun light and grow light. 3 to 4 inches is about the time I feed fish and seaweed in a more stronger solution.

[Cole_Robbie]

I've always kinda wondered why a person couldn't wire up a tanning bed light and use it to grow indoor plants that are resistant to UV light. Obviously exposing one's self to the UV light isn't very smart, but it could be run on a timer and away from people.

[Darren Abbey]

Originally Posted by Cole_Robbie

I've always kinda wondered why a person couldn't wire up a tanning bed light and use it to grow indoor plants that are resistant to UV light. Obviously exposing one's self to the UV light isn't very smart, but it could be run on a timer and away from people.

Not so extreme, but I've thought about including a UV bulb or two in my setup for just this purpose.

[lavanta]

Here is a clear write up to read, there is plenty more on the net:
https://www.boundless.com/biology/te...ght-375-11601/

As long as you provide enough energy in the 400 to 700 nm range your plants will be happy. That spectral range is 80 to 90% transmitted through regular window glass, otherwise there wouldn't be greenhouses.

As mentioned above fluorescent lights are no match for natural light, or light through your window.

[Jwb4707]

I grow all my plants in front of a south facing slider door every year, with great results, but it's due south. Just have to keep turning them as they grow.

[digsdirt]

I grow all my plants in front of a south facing slider door every year, with great results, but it's due south.

"Great results" is a relative term and only in the eye of the beholder. There is no comparison between the results of plants grown using only window light - no matter its direction - and those grown using good supplemental lighting. Even in the greenhouses we use supplemental lighting at seed starting time as the sunlight at that time of year isn't the correct spectrum, intense enough, nor available for enough hours.

If you are happy with your results, fine but please don't assume that they couldn't be substantially improved by the use of supplemental lighting.

Dave

[Jwb4707]

Well Dave, I didn't claim any of that, just stated that I have great results, in any ones eyes, not just mine. Come take a look at my garden. You want to spend hundreds of dollars on lights, then your electric bill, knock yourself out, for some of us, it's unnecessary.