16/8 light Q

[michaelpeg]

if is start my plants under 16/8 light will they flower eventually or keep vegging until light switch? I am trying to keep the light the same as the daylight outside for when i put them out.

strain- nirvanas swiss cheese, flower time 6-8 weeks, indica sativa hybrid

nirvanas kaya gold, flower time 7-9 weeks, indica sativa hybrid

thanks

michaelpeg Reviewed by michaelpeg on 03-23-2011. 16/8 light Q if is start my plants under 16/8 light will they flower eventually or keep vegging until light switch? I am trying to keep the light the same as the daylight outside for when i put them out. strain- nirvanas swiss cheese, flower time 6-8 weeks, indica sativa hybrid nirvanas kaya gold, flower time 7-9 weeks, indica sativa hybrid thanks Rating: 5

[emilya]

they will keep vegging until the dark period gets to 12 hours. At 12 hours of night or more, the plants feel winter coming on and they switch to flowering mode in order to reproduce and keep the species alive.

Most indoor growers use either 24 hours of light or at minimum 18 while in vegetative (there is a controversy as to whether the 6 hours of darkness is needed at this stage) and then switch to 12/12 to start the 8 week flowering cycle. So at 16/8 the plants will not go to flower unless they are an auto-flower variety, but many would argue that you are wasting 2-8 hours that you could be using to provide the light which gives the plant the energy it needs to grow.

Also keep in mind that if you put the plants outside in the spring, it is going to be a long time before the nights get back to 12 hours or more to send the plants into flowering mode and start that 8 week cycle. This is why indoor growing is so popular... it gives you much more control.

Emmie

[GaGrown]

they will keep vegging until the dark period gets to 12 hours. At 12 hours of night or more, the plants feel winter coming on and they switch to flowering mode in order to reproduce and keep the species alive.

Most indoor growers use either 24 hours of light or at minimum 18 while in vegetative (there is a controversy as to whether the 6 hours of darkness is needed at this stage) and then switch to 12/12 to start the 8 week flowering cycle. So at 16/8 the plants will not go to flower unless they are an auto-flower variety, but many would argue that you are wasting 2-8 hours that you could be using to provide the light which gives the plant the energy it needs to grow.

Also keep in mind that if you put the plants outside in the spring, it is going to be a long time before the nights get back to 12 hours or more to send the plants into flowering mode and start that 8 week cycle. This is why indoor growing is so popular... it gives you much more control.

Emmie

Emmie,
Great user info! Lemme add this about other strains and light.. Jack herrer will flower at 14 hours of light. So when your vegging Jack with 14 hours of light,trying to save on your power bill.. Just go with the 16 -18 hours of light for proper vegging and no surprises... Big Bud and Most Skunk strains and it's hybrids are stable enough to go with 16 hours...But.. Don't!18 is rule of thumb!

[michaelpeg]

emilya thanks for the reply. outside plants start flowering when the days start getting shorter, they dont have to wait until 12 hours of sun. also if you take a plant from 24/0 and put it under 16/8 im sure it would most definitely flower sensing shorter days.

gagrown, are you sure i should go with 18/6 even though when they go outside the daylight will be 16/8? i here once a plant starts revegging you lose a ton of bud in the end and i dont really want to risk it.

[oldmac]

Hey there michealpeg,

You are correct that a plant does not need 12 hrs of dark to flower, but most hybreds we grow will need more then 8 hrs of dark period to induce flowering. Typically 10 hrs or more of darkness is needed. Also the amount of dark time needed to induce flowering is more then the amount of dark time needed to keep it in flower.

12/12 has become the de-facto standard for indoor growers because it works with at least 95% of what is being grown. It will not work for landrace sativa's or very heavy dominate sativas. They will continue to veg till they are ready to flower, determined by something else.

When a plant is growing, every time it goes dark it starts to make certian chemicals (auxins) and a hormone (floragen) and when it sees light these chemicals break back down. It takes a certian level of these, for multiple cycles, before the plant is induced to flower. This level is strain dependent.

Hope this helps in understanding flowering.
BTW, the flowering stage of all plants is the least understood stage by plant biologists. It is only in the last 10 or so years that the hormone related to flowering was idenified and it appears that many auxins are hormones. Also textbooks written before 1990's typically say that a plant once into the developement stage of flowering cannot be put back into a vegative state but we have learned since, that just ain't so.

OM :jointsmile:

[GaGrown]

emilya thanks for the reply. outside plants start flowering when the days start getting shorter, they dont have to wait until 12 hours of sun. also if you take a plant from 24/0 and put it under 16/8 im sure it would most definitely flower sensing shorter days.

gagrown, are you sure i should go with 18/6 even though when they go outside the daylight will be 16/8? i here once a plant starts revegging you lose a ton of bud in the end and i dont really want to risk it.

I have the same revegged plants for the past 7 years. You lose nothing. It's all about how you take care of them and whether or not you transplant into larger pots. All ya gotta do is trim the rootball. You'll be Golden! That 2 hours of light will not make them revert back to flowering when your photoperiod in your area is that long. When the days get shorter towards the fall then they will flower. I put cuttings out in August and that keeps them short and stocky as well as they start to flower in two or three weeks from there.Harvest in Oct. or Nov.

[michaelpeg]

thanks alot guys, lots of good info. no yield difference in reveg plant, that is good to hear. gagrown, any negative effects from trimming the roots? how long until new plant growth after trimming?

[GaGrown]

thanks alot guys, lots of good info. no yield difference in reveg plant, that is good to hear. gagrown, any negative effects from trimming the roots? how long until new plant growth after trimming?

When you trim the roots,only take about an inch from each side.Transplant and then water with KLN Rooting hormone and superthrive. 10 drops of superthrive per gallon. 3 TSP per gallon of KLN. It'll root back nice and give you room in the new pot,too..