worries for light deprivation

next spring i want to have a light dep tunnel so that after it gets dark each night i can cover the lovely ladies up and take the covers off like 11-12 hours before sunset Im worried about heat light leaks causing hermies and humidity do i need airmovers under the covering what type of covering should i use is heavy duty tarp enough to block the morning sun or would sometipe of blackout be better thankyou all so much blessings from the most high happy holidays

punctuation is your friend man, that was a struggle to read and I am still not sure I understand exactly what you are trying to do.

You can get blackout plastic from greenhouse suppliers that is used just for this purpose, its black on one side white on the other. You should cover your plants at 12 hours then remove the cover after darkness that way there is no humidity build up

Use tarps

Use tarps

but not a blue one , even some brown ones let sun in . Black one are hard to find . I found the best ceapest covers for greenhouses at a diesel truck used parts place . peace f punctuallity

hi The Bling,i have some experience with shading plants, for those light leaks problems i think that Jah (b)less gave you right advice, and humidity well..... there will be high humidity for sure, you can solve it with choice of certain strain, haze hybs can take alot of humidity without mold problems, but theyre also longer flowering plants, and if it will be spring grow i guess you need some fast flo strains, so then you should have good airflow whent it is covered and add some good dehumidifier, just turn that dehumi on for a little while, it doesnt need be turned on for long time, it also kills organisms in air which can attack your plant

but i think the best is learning from your own mistakes.....

peace an good luck with your grow

good luck

good luck

i don't understand why you would want to deprive your plants of light unless you are looking to either pull out the indica or sativa side of a specific plant or some other trait that you are looking for. DJ short has done work along these lines and this is how he isolated some of his berry strains.
I do know that at the first sign of sex of an outdoor plant determine the length of daylight for that day,then count back 10 days and determine the daylight for THAT DAY. That will then tell you how many hrs of darkness that plant will need for blooming.
Any way depending on what you are doing and how much time that your going to have to do this you better be very dedicated to follow through with your plan just 1 screw up could possibly get your whole patch.And for maybe 2-3 hrs of work a night every night IMHP not worth the time of having that last beer with the crew after work or dinner date with the old lady hell forget going out of town too..LOL
And in case you don't want to go through all the hassel of figuring out all the light cycles look here they have done it for us FOR THE WHOLE WORLD any city any country god bless them :
http://www.gaisma.com/en

Good luck with your project keep it green......Buzzerd

you can harvest two to four times in a green house using light deprivation techniques

I just started pulling tarps over my two 15x16' hoophouses tonight at 8pm. We'll pull the tarps off at 8am every day.

I did a lot of research and bought 2 DuraTarp Silver Super Sun Blockers from creativeshelters.com... one 40x50 and one 40x40 (i originally was going to do one 50x16' hoophouse with a lot more plants, but the sheriff came by and made me take some down)... anyhow, by no means do these tarps block out all the light. I went inside and let my eyes adjust and i could just barely see light comeing thru the tarp. Amd its 8pm... the sun is behind treees at this point in the day, so we're not even talking about direct sun.

I am hopefully going to be able to get away with adding a layer of 6mil black plastic and not have to go out and buy a ton of expensive "panda" plastic... the kind you use to line the walls of an indoor grow room.

Hi there, I run lite dep, ive got a crop at 54 days now.

What ive found works best after a few years:

I use a poly silver/black hay tarp from farmtek. Silver side up to reflect lite. There is a bit of lite (pinholes) in the tarps, but they work just fine. Ive not had any hermie issues in 4 years of using this tarp.

On humidity, there are ways around it. One is to put the tarp on at dark, take it off when it totally dark, then put it back on before sunrise. If you have alot of air moving (fans) you can just open the ends, its much easier to close the ends at 4 am than pull the whole tarp.

I live in an extremely dry area with low humidity, so I just leave the tarp on til its time to remove it. When I pull it off my humidity is in the 90's, but within 45 minutes it is back into the 30's. IMO this is considered 'humidity shock' and wont allow any type of fungi to establish itself. I think it you tried this in a humid area it would not work (leaving the tarp on and letting the humidity get so high).

I also use only shdeclothe on my greenhouse frames in summer. This allows exponentially more airflow. I roll up the covers and leave them attached to the frames, and can pull them on when foul/cold weather comes in fall, to keep my buds dry.

Good luck!

SHS

I considered the farmtek tarp, but it was twice the price of the Duratarp, so I went the other way. We started working with a 6mil black visqueen under the Duratarp. We pull the black plastic first in one direction, then the tarp over in the other. It is now completely dark in there- after about 5 minutes of eye adjustment there is zero visible light. d-a-r-k

SHS: I don't have the experience to disagree, but the sum-total of the wisdom I have collected from large commercial black boxes does disagree that absolute blackness matters. Strains that are prone to hermaphrodism will herm (so no awesome landrace sativas) and later blooming are the reasons cited for the absolute darkness regime. I have been specifically warned against opening up for the late night.

While I have not grown extennsively in N.America, I have grown in Central America. There, we use supplemental light to grow hybrids and indicas. We have found that, without a doubt, if we start to play with light cycles the process benefits significantly by imposing complete darkness during the dark part of the cycle.

I still appreciate and respect your experience-based wisdom. It makes me think "I'm glad its totally dark in there, but I guess I don't have to be so paranoid that a pinhole leak is going to ruin everything." so thanks.

Sooooo... 57 days in? I'm jealous. That's basically when I got back from Central America... I had this fantasy that my black box would be up a week after getting here, but it took just a wee bit longer- had to find a place and build 500ft of fencing!

So, what strains? Hows it going? How much longer till it comes down?

Nice thread here, glad I found it...I'm tryin to do a lil light dep now in my hoophouse. Was rocking the wal mart heavy duty which apparantly let too much light in cause nothing showed any signs of flowering after almost two weeks.

Picked up my 20x40 Duratarp silver yesterday and this thing is the trick. Got it DARK in there now! Two days in, I should know soon if it's workin...

I would FOR SURE add a layer of 6 mil black plastic under your duratarp. Unless you've got that walmart tarp under it already. I could definitely see light coming thru the super silver 'sun blocker'...

I tried doin' something like this. I gave up. Let me know if you get it to work.

its working. i am nine days in, and everything looks like an indoor at 9 days of 12/12, more or less. so far, so good. I had to start digging holes under the 65 gallon smart pots because the plants were getting too big for the 8 foot high hoop house. I'll take some snaps tomorrow cuz this is what it looks like now.

Lookin good nomaad

I had to do some digging as well...damn things hitting the top!

I gotta say though it seems with only the duratarp on, it's very dark even under the intense sun. I'll play around with it though...might as well use those wal mart tarps for something

So it looks like you got a few running full season out there...what kinda strains do you run? Smart pots are solid, but I ended up making my own from fencing and landscape fabric. Got a thread in OD called Fisher's Farm, you can check me out

Looking good nomaad, we are in the process of taking our lite dep down now, no herms yet....... Looks like it will yeild in the 20-ish lb range.

Strains are:

jackie O
ssh
nebula
krystallica
herijuana
white russian

Trying to get it down so we can reload asap. Got another group in the wings.

What are you using to hold your tarps down. We went with 5 gallon nursery pots of gravel.

SHS

I call them water sausages. They are the things that you use to hold down over-winter pool tarps. They make both single and double bladder versions. I use the doubles. They seem very resilliant... we'll see how they do over the next 7 weeks. http://www.poolproducts.com/SPP/product_family.asp?family_id=2526

Congrats on the expected yield. I don't want to get my hopes up, but I will say that something in that range would satusfy me and go a long way to getting out of the debt I have incurred getting this grow together (We moved here with the entire family from Central America less than 3 months ago) How many plants in your dep? What sized containers? Tell me more about your feed schedule. I have 18 in 65 gallon smart pots (totally legal unless my full summer plants start to flower before these come down.) They are filled with Roots and 707 in a 2:1 ratio.

Strains are Sour D, Headband (not the real deal Chemdog #1), True Headband (real deal clone only), Grandaddy Purple, Bubba Kush, and 3 strains called "Maui" "Blueberry" and "Skunk" that are not what they are called, but I have seen them all grown out and they are all great yielders that have the qualities that their names would suggest. The "Maui" is a particularly sick looking plant that I would love to ID... pix of it at:

http://www.icmag.com/ic/showthread.php?t=126332

fisher15 said:

Lookin good nomaad

I had to do some digging as well...damn things hitting the top!

I gotta say though it seems with only the duratarp on, it's very dark even under the intense sun. I'll play around with it though...might as well use those wal mart tarps for something

So it looks like you got a few running full season out there...what kinda strains do you run? Smart pots are solid, but I ended up making my own from fencing and landscape fabric. Got a thread in OD called Fisher's Farm, you can check me out

Click to expand...

I would use whatever tarps you've got on hand... the amount of light that came thru the duratarp was very little, but once my eyes adjusted, I could make out the shapes of the plants and my gardening partner's head. With the addition of the black 6mil, we cannot see anything even after being in their for more than 5 minutes. I feel like the same light leak rules that apply to an indoor should apply to the the light dep. And every time I see herms in sombody's black box it has been directly attributed to light leaks. So... better safe than sorry. I guess it also matters what time you are pulling tarp. If you are pulling at 9 instead of 8, the amount of overhead light trying to get in is less and therefore might not go thru the duratarp...

My outdoor 18 are in 200 gallon smartpots with Roots/707 in a 1:2 ratio. The strains are:

(2) AfPak
(1) Og Kush (Tahoe cut)
(1) BlueDawg (DJ short BlueBerry x Chemdawg #4)
(1) Headband (Chemdawg #1 cut)
(1) Trainwreck (Arcata cut)
(1) Blue Dream (clone-only)
(2) Bubba Kush
(1) Grandaddy Purple
(1) Grape Ape (Kyle Kushman cut)
(1) Razzberry
(1) Berry White (clone only- very special pheno of Paradise seeds White Berry)
(1) "Blueberry"
(1) Sour D
(3) "Maui"

There are also 18 smartpots out there filled with veggies and the same potting mix as our light dep. We originally had 36 in the light dep but the sheriff came and made us take some down. Them's gonna be some siiick heirlooms in that soil.

I guess I should start a thread for the grow. Its my first, but I am the kind of guy that goes big and usually does pretty well. I am hoping for 3-5 lbs in the full season 200's. I am feeding aggressively and hand watering...

The plants are a little behind where they should be due to very cold and cloudy temps here for about 3 weeks. Everything started flowering. We chose to dead-head all the bud sites rather than waiting for a revert to flowering... they are just now recovering. I had an NL#5 and a Lemon Drop in my full summer garden that I had to transplant into 20 gallon bags and put in the light dep because they just refused to revert.

Again, I should just start a thread for the entire grow. Sorry to hijack.

Hiya nomaad, my coldframe is 12' x 24' x 8' tall. This run we had 20 plants in 10 gallon hempys tubs of perlite. We dripfeed gh nutes using the lucas formula.

Our full season girls are in 20 gallon hempy style tubs of perlite sunk into the ground. We expect 3 lb per plant from these, with a few going bigger. They are out in full sun, we use the coldframe for lite dep then tying up and finishing strains (mostly sats) that cant handle our windy stormy (rocky mountain) weather.

our full season outdoor girls are

trainwreck -e32 cut
pakibubba
abusive og x blueberry
original diesel
ak-47
high tech (abusive og x jackie o)

and some test crosses we made last winter in a seperate patch offsite.
We are 'with paperwork' here as well, great isnt it......
Sounds like youve been busy spinning up a grow this spring, best of luck to you, hard work pays off!

SHS

light dep tarps

light dep tarps

I've been looking for better tarp materials and found this breathable light dep tarp material:

http://www.foreverflowering.net/?page=light-dep-tarps

cheers