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 $$.
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?
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.
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!
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.
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
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.
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.
