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Greywolf
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Maybe it's because a lot of my experience comes by way of the military, and being supplied with the products of "The Lowest Contract Bidder" -
Who knows...

I have been playing with the idea of maybe setting out an array of lights amongst my tomato cages that would be in outdoor sockets, and supplied by an extension cord with a simple appliance timer at the end.

Since above it was mentioned that lights were set to go for 16 - 18 hours, I wondered if from maybe sundown to two or four AM would add supplemental lighting (of a kind) that would help outdoor plants grow better...

It might also be an excuse for security lighting in the back, since there have been a few questionable incidents lately.

Those could be offset by lights coming on in adjacent areas a few hours before sunup
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The Helpful Gardener
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I'm not sure going past the the diurnal period would be that helpful...

Plants need to rest too. It's not sleep, but it is a downtime when they close stomata, decrease their functions, and just chill. Probably let's them tend to other functions in much the same manner our bodies do through sleep. I'd be worried about stressing them for a prolonged period, especially as they mature...

You know how it is; kids want to stay up late, but us old folks need our rest... :lol:

HG
Scott Reil

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Greywolf
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So - (if I understand this properly) - For a young plant such as a sprout or a seedling, this might be a good thing, but a mature plant is best off if it is not forced into an unnatural cycle....

Is that right?

But if flourescent light lends most to green growth, is it in any way beneficial overnight?

And when should we just quit it at all....

OR: If a plant began it's life out of doors, subject to normal seasonal lighting from the sun, is it best just left alone?
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rainbowgardener
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I don't think it is a difference of young vs mature. We leave the fluoros on the seedlings for such long periods to make up for the fact that it is SO much less light than sunlight. I don't think supplemental light would be of any benefit to plants that are getting 8 hrs a day of full sun.
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Halfway
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Do some research on Alaska's growing seaon and light hours per day. Easy search and fascinating reading.

CFB's are not as efficient as standard 48" shop lights with T8's when looking at cost/light efficiency. T5's are very efficient, but the costs increase at a relative rate. Sodium and metal halide are the most efficient, but not conducive to most folks pocketbooks or needs.

Ballasts and starters are only rarely needed and mainly for "hard-wired" systems.

I'm no expert, but spent many, many hours researching and experimenting over the past year(s).
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garden5
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Once your plants are outside, I really don't think that having fluorescents on them would do any good; they are really weak compared to sunlight.

If they are on indoor plants, you should try to have them on during the daylight hours, like 6 AM to 10 PM. I just think that since this is when the plants will be receiving light when they are put outside, why not go along with it.

Good luck with your plants.
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The Helpful Gardener
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I remember seeing a study on blue spruces declining because of long term exposure to parking lot lights at a mall. Can't find it...

Here's a study on solanaceous plantswhere 14 on 10 off beats 16/8...

Here's [url=https://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TC3-3T11SND-6&_user=10&_coverDate=05%2F29%2F1998&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1306741873&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=5ddd3ffe2d160c920343e508c7f9d284]another study on tomatoes[/url]that supports the first...

So I'd say up to fourteen hours of light is beneficial. Not so much after that...

HG
Scott Reil



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