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lighting mix and match lighting - natural and artifical - potential for damage?

Hi All,
 
A quick one: is it possible to mix and match lighting for young seedlings?
 
I've just started using a light box (as per my previous post in this section) but the days are now starting to get around 20 deg C at my location (certainly not strong sun, just warm).
 
I wonder if I can put my seedlings out for a few hours during the afternoon or so and then back into the light box without causing any sort of damage due to the mixing of light ?
 
Any thoughts ?
 
Regards,
 
Tim
 
Tim,
 
I've been thinking about the same thing, if you don't mind i will follow along for some answers.
 
Jimmy
 
There won't be any kind of damage assuming they don't get sunburned. Mixing light isn't the issue, its that they won't have been exposed to UV while inside. Bring them in after only 45min-1h the first week or so, then leave them out for a couple hours each day, and eventually they should be able to stay outside.
 
The outdoors is a much harsher environment.  Wind. reduced humidity and a much brighter light source will all overwhelm a young tender, innocent indoor-raised plant.  Water loss and sunburn are the two main stresses.  The plant will need to increase it's root-to-foliage ratio to cope with the increased water demand  This takes a bit of time.  Ease the plants into it over a few weeks and they'll do fine.
 
As Cruz says, start at an hour or so in the morning or evening and go up from there, cutting back outdoor time during windy, drier, or warmer-than-average weather.   After a week or so, you can probably place them under a tree or similar shade, so they get a few hours in the AM and PM, while being shaded from the worst of the mid-day sun. 
 
AFAIK, the 'mixing' of light sources, in and of itself, is not an issue in any way.
 
Ah, the penny drops !
 
I completely forgot the UV issue (being worried about so many other factors) and once again I have found out it that it pays to ask in advance.
 
I was thinking more along the lines of "it's going to be 22 today so I will put them out under shadecloth for a few hours", but that is in rapid response to subtle improvements in weather at the end of winter, i.e. periods of 3 or 4 days of sunshine then overcast again.
 
So, based on the advice here, by the time the plants start to harden up a little, the weather would go back miserable again, completely negating my efforts of mixing light sources.
 
I think I will wait, but many thanks to the responders.
 
Regards,
 
Tim
 
PS - Jimmy, if you are thinking the same way, have I missed any pertinent questions do you think ?
 
Also, just putting this out there, that my plants still droop their leaves even after recovering from sunburn and all that. The heat of the day just prevents them from getting enough water through the stem. They don't die or anything, but need watering much more frequently, although this only happens in direct sun on days 84F, so that would be 29C and above.
 
It might still be worth the hassle, if you have the time to spare...
Even if the plants revert to a 'wimpy' fitness level when brought back inside, the increased light they will enjoy outside will likely allow them to grow a little faster than they would indoors.
 
teejay said:
Ah, the penny drops !
 
I completely forgot the UV issue (being worried about so many other factors) and once again I have found out it that it pays to ask in advance.
 
I was thinking more along the lines of "it's going to be 22 today so I will put them out under shadecloth for a few hours", but that is in rapid response to subtle improvements in weather at the end of winter, i.e. periods of 3 or 4 days of sunshine then overcast again.
 
So, based on the advice here, by the time the plants start to harden up a little, the weather would go back miserable again, completely negating my efforts of mixing light sources.
 
I think I will wait, but many thanks to the responders.
 
Regards,
 
Tim
 
PS - Jimmy, if you are thinking the same way, have I missed any pertinent questions do you think ?
 
Tim, can't think of any other questions; have some new jalapeno seedlings splitting their time under a grow light and outback under the patio in indirect sunlight.
 
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