How sensitive is the marijuana plant to small light leaks ?

[Higher Power]

Once again fellow growers @ IC, I have a question. I have my plants in a room that has a small window. There is always a small amount of light (very small) leaking through. I covered the leak with a small blanket but a small amount of light still seems to get through every morning. The room still remains dark, except for this light leak which seems to get filtered by the blanket. I wanted to know how sensitive is our beloved plant to small light leaks like this one ? Does it affect the photoperiod ? Thanks

 

[okanogan green]

Hello there higher power. I have heard that small light leak problems can lead to female plants going hermie on you where they sprout male flowers (balls). The dark period ideally should be very very dark just as it is at nighttime in the blackness outdoors. It is light pollution that you have and it can lead to problems. I believe that it also could depend on the strain that you are growing if it is sensitive to this problem of leaking light into your grow. Good luck and I hope that this helps a little. Cheers.

 

[Babbabud]

Get rid of the light leaks.

 

[Higher Power]

I will have to correct this problem immediately. I was worried that they would revert back to veg. I definitely dont need any hermies. I have had this problem for a couple weeks. Hopefully I am not too late.

 

[NoSaint]

If you've had a light leak and some damage has been done, then fix the light leak, will the damage reverse itself?

 

[Oldmac]

The room still remains dark, except for this light leak which seems to get filtered by the blanket. I wanted to know how sensitive is our beloved plant to small light leaks like this one ? Does it affect the photoperiod ? Thanks

Higher Power, The sensitivity of mj to a light leak is very strain dependent. Some strains will turn hermie it seems if you look at them cross-eyed or curse them out. Others will put up with lots of abuse. I had a problem trying to make a plant go hermie using "light poisoning", but I admit that's rare.
It has no effect on the photoperiod (time lights are on), it is the interruption of the dark period that causes the problem. The plant times the dark period, and that determines what the plant will do, veg or flower.

 

[alpinestar]

If you've had a light leak and some damage has been done, then fix the light leak, will the damage reverse itself?

thats totally dependent on the plant and how much light it has received
ive seen grow areas (with light leaks) that had plants flowering right beside ones that wouldn't

even if you don't end up with herms, it will definitely mess with the flowering time

 

[Oldmac]

If you've had a light leak and some damage has been done, then fix the light leak, will the damage reverse itself?

Simple answer is no. Once it has made the decsion to go hermie it will continue to go that way. If you catch it early enough or you think it's dark period has been disrupted, you could use a product like Reverse that's made by Dutch Masters. It effectively kills off the male flowers so they can't produce pollen. Sometimes if you're growing a mixed batch of plants or you have alot of high value growing going on, you can use Reverse as insurance against unwanted seeds.

 

[magiccannabus]

I had a small light leak in my grow for the first 45 days of flowering. It was coming in from the veg side and bouncing through the ducts to reach the flowering chamber. The trickle of light was so tiny that I literally had to shut myself in the cabinet to figure it out. That tiny bit of light leaking in pretty much ruined my grow. Yield on the plants under the leak was cut by at least 75% compared to the ones not under the vents, and both plants under the vents hermied out really bad. The other half did much better, with massively better yields and way better potency. I am still really shocked at how badly this ruined my grow.

 

[Higher Power]

Damn ! Im a bit worried now. The light leaks in the morning right before my hps comes on. I sure hope to God I didnt ruin my crop. I got some awesome genetics going.

 

[magiccannabus]

Is the leak at the same time each morning and how long does it last? If it's close when lights come on, it's less of problem. It's those middle of the night leaks that are worst.

 

[Higher Power]

Yes Magic its usually at around 7am. My lights turn on at 9am. I have been checking my plants for nanners & havent found any. This has been happening for 1week. The leak is in the corner of a small room, & my plants are at the opposite side.

 

[CANNACO-OP]

Second the strain. some do some don't

second also time of day and consistancy of leak

i would try to fix it

peace

 

[dobo]

I always wondered about light leaks and hermies, i dont think small ones with low light levels should effect them too badly as imagine how much light they receive off the moon when they are in the wild? or is the light different? anyone got the answers why plants don't go hermie under moonlight?

 

[TGT]

I had a plant that wouldnèt bud just because a small street light about 100 yards aways.

TGT

 

[mrjim5000]

I always wondered about light leaks and hermies, i dont think small ones with low light levels should effect them too badly as imagine how much light they receive off the moon when they are in the wild? or is the light different? anyone got the answers why plants don't go hermie under moonlight?

I would agree with this, I think a small light leak is not the end of the world when growing bud, admitidly I only have 4-5 grows under my belt. Large irregular light leaks can cause problems, but I would guess in most places with small light leaks it is other factors such as heat or other stress that causes the hermies. Nighttime is not pitch black, there is the moon and stars which can be incredibly bright on a clear night with a full moon. There has to be a notable difference between the MJs 'day' and 'night' but I have successfully grown with the dark period not being pitch black and had no bad effects, the key is that the darkness level is consistant, the problems happen if you start actively shining bright light on the plants during the dark phase and messing with their routine.

I had a plant that wouldnèt bud just because a small street light about 100 yards aways.
TGT

How do you know it was the streetlamp that stopped it budding? Did you have clones planted in identical soil, nutes and air conditions and the only thing different was the lamp?

 

[elfstone]

So if one has a black/white plastic enclosure that is closed reasonably tight with velcro and tiny amounts of light leak from the adjacent veg room, would this ruin the flowering cycle?

 

[stealthroom]

my point .02
from seeds sexed and then flowered= stressed plants and maybe hermies
from feminized seeds = hermies. maybe stressed
clones its random based on strains and phenos

 

[dotblunt]

Funny how one obvious fact gets overlooked here, plants have adapted to growing outside and must contend with the cycles of the moon which we all know gets rather bright when it is full.

Obviously the best cure is complete and total darkness, but it is important to keep in mind they are accustomed to a certain amount of light leakage that already occurs in nature and last I checked many many outdoor growers have pulled off successful crops without going hermie.

But fix the light leaks, extra insurance pays dividends.

DB

 

[Grand Funk]

I've heard different theories over the years about this, and even seen some experiments done on the subject. Like said before, some strains are more sensitive. Especially the land race genetics, which are acclimated to a certain photo period. Tropical sativas are most affected by light leaks in the dark period.

To be safe......as to eliminate any doubt, I would darken that window as well as you can. Better to be sure, than to wonder....right?