Plants under grow-lite

Discussion in 'HortForum' started by Ottawa-Zone5, Jan 12, 2008.

  1. Ottawa-Zone5

    Ottawa-Zone5 Active Member

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    In nature plants get a period of rest from photo-synthesis at night. Will it help the plants under grow-lite more if the lights are on 24 hours, or will it help if the lights are turned off for a few hours. If turning off the lights for a few hours helps the plant in some way then it will also save energy and $$.
     
  2. jimmyq

    jimmyq Well-Known Member 10 Years

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    plants respond to the cycle of light and dark. I dont think having the lights on 24 hours a day will be of benefit in the long run. What kind of plants are you growing?
     
  3. Ottawa-Zone5

    Ottawa-Zone5 Active Member

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    Thanks. Actually I was planning to make a grow-lite structure for a specific size space available for growing from seeds (such as tomatoes, cucumbers, bitter-mellons, egg plants etc) as well as rooting hardwood cuttings (such as figs and magnolia). So the question was to find out if I should include a timer for turning ON and OFF the lights or just leave it ON all the times.
     
  4. growest

    growest Active Member 10 Years

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    I've tried running them 24 hrs, and some plants definitely suffered...tomatoes are one example. They became distorted and significantly slower growing than those with a "rest" at night.

    I later read confirmation that many (tho not all) plants do grow better with the night rest.

    I have set my timer here for an 8 hour dark period...similar to our latitude in June, which seems to produce rapid but not problematic growth. As you say, this also saves power...not a bad thing!
     
  5. jimmyq

    jimmyq Well-Known Member 10 Years

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    when I worked as a fertilizer sales guy in the hydroponics industry here in BC the usual regime was 12 and 12 hours of light and dark during vegetative growth and 18 on 6 off for flowering stage.... I think it was for a specific plant species though....
    As for a structure there are many, usually including a sliding or adjustable height ability in the framework.
     
  6. Ralph Walton

    Ralph Walton Active Member 10 Years

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    I think it's actually 18/6 (light/dark) for growing and 12/12 to induce flowering, simulating the shortening days of fall (for that specific species). Some recommend 24 hr light for sprouting and rooting, though I use 18/6 for that too. Grapes seem to work best at 16/8; I'd assume other species have their own preferences. Some plants are very sensitive to light in the dark periods - even 5 minutes of light can "confuse" the plant and set back flowering by days or weeks.

    Ralph
     
  7. constantgardener

    constantgardener Active Member 10 Years

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    If you're looking for max growth, you might try a heating mat under the young plants. I started using one received as a gift at Christmas & have new plants sprouting from leaf cuttings that just wouldn't apply themselves before...regardless of the # of hrs of light or how close, etc. some of these just grew roots, nothing else. Less than 30 days with the mat & I've got miniture plants showing up. This is the typical heated mat sold at any nursey store. Good luck with yours.
     
  8. Ottawa-Zone5

    Ottawa-Zone5 Active Member

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    Hello Everyone
    Thanks for your very informative replies. These will make difference in seedlings preparation.
    The last post mentioned a Heat Mate. I guess the standard ones available are about 10" x 20". I would have liked a bit bigger (but not the 20" x 20" big). Lee valley is just a block away and they have this 9" x 19":
    http://www.leevalley.com/garden/page.aspx?c=1&cat=2,44713&p=44602

    Also, Lee Valley has this Roottrainer that may go nicely with the above Heat Mate:
    http://www.leevalley.com/garden/page.aspx?c=1&p=10559&cat=2,44713,40757&ap=1

    I was thinking of removing one or two 4-cells packs to make room for moist peat moss under and around the other 4-cell containers properly placed in the bigger container for better heat dissipation and absorption.

    Your comments/suggestions will be appreciated.
     

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