48 Hours Of LIGHT Before Harvest! (NOT DARK!) 

Dr Bruce always keeping it real. Cheers.

I tried this, and Bruce is right. I will never go back to darkness before harvest.

Dr. Bugbee is an a amazing scientist. It's so hard getting growers in the community to ditch their broscience. This man is an international treasure.

I’ve been watching Dr. Bugbee’s old videos the past couple weeks so this interview is perfect timing 😄

I’m glad u are doing clips of the podcast now 💯

Exactly what I've experienced, Agree 100% with him on this subject for sure.

Great collab. Keep it 💯 Big respect as always to Dr. Bruce Bugbee, MrGrowIt, and MiGro also for sure. Great LED innovation and research, do not stop this snowball of research.

One of the best topics that needed way more information that what was out there before this man said this. I was going to start turn light off the last 48 hours. but now i will now.

Makes sense, this dude is very educated on this I would definitely take his opinion.

Im about to put my ladies into flower tomorrow im so glad i ran into this MRGROWIT. Thank you for everything you have taught us in our community. I also love FROM THE STASH podcast you all are perfect for information.

I ,we can all learn from Dr.Bruce. this guy is Awesome

Just do the best u can from start too harvest, dont expect a “hack” like turning of your lights too turn your harvest into topshelf❤

The Great Doctor always gives great info.👍🏾💯

Good shit my dude, keep it coming

12/12 is fine. I had a nice frosting happen after adding a bunch of extra cool white CFLS to my grow room. 150w of the blue CFLS and put them close to the flowers. In pots, sunlight through the window glass, or UV a week before harvest worked best for me. I was giving both sunlight through the window glass and grow lights.

Makes sense for sure.

thanks again Chris

I grew my plants outside,..au natural, sunshine/heat and water, lots of water, with the occasional feeding...so thats how I do it, and I dont have any light after the sun drops,..fingers crossed, as there is amber and white hairs, but the bud is so heavy at the ends...I still continue to let them go do whatever they are going to,...I hope I harvest them in time..

I use to do the 48 hrs of dark at end but stopped after I realized it wasn’t helping at all & my soil would immediately start growing mold which would make my buds get a moldy terp taste, it was beyond harsh!!

def all makes perfect sense , great info !

I think realistic timeframes to achieve any level of terpene development or preservation during the life cycle of this plant is to start from the beginning stages of you plant. I treat my tent like a typical lifecycle that this plant would experience in its natural environment. The last 3-4 weeks of flower I stop feeding and use just regular tap(no chlorine). I also never defoliate in the last 4 weeks also. I also dial back light intensity from 100% to 80% and from 18 hours of light to 14-16 depending on the cultivar and closely watching how it handled said conditions throughout. If posssible I dial back the temp to 70-75 degrees F.

I tested this in Florida in 2014... blind tested, 2 plants, outdoor grown. We tested it, 4 growers and 4 trimmers with indoor and outdoor experience. We could not tell which plant was in a 48 hour dark room before chop. I put it inside a dark closet with clean fresh florida air, 48 hours... and we all 4 could not tell which was which.

Dr Bugbee is living Legend! 🔥 thanks for this video

As always, thanks for the education Chris.

in nature the nights get cooler as the flowers develop. keep them warm in the day and cool at night in the grow room seems to make sense. changing the light at the last minute would confuse the plant , not sure it makes any sense

Makes sense i always knew that was a myth. I always use light until harvest with amazing results lowering temps in the last couple weeks

Interesting, worth a try

It used to be a thing back in the day outdoor growing, harvest at midday, the day after a full moon.

He's right, fresh plant oils are less toxic and plants detoxify/respire at night. Watching this because of citrus fruit such as orange peel's terpenes. They were used to cure ailments in other countries where people look younger and healthier than people of the same ages elsewhere.

Ok thanks i will try

Definitely trying lights on this harvest. I have always did lights off for 48hrs.

Oh Man 🥺 I was hoping for a new batch of AWESOME information. THIS WAS GREAT FOR those about to harvest 🤜🌟🤛🪴🪴🪴

Volatility is the reason we run 24 hr darkness. If you can smell em they're leaving. Terpenes

Makes sense

I think this man is spot on. Great subject to touch on.

I've done the same, two runs with 48 hours of light. Light intensity from 850-900 PPFD, running a Spider Farmer SE- 7000, and dropped the Temps to mid 60's for the duration. I watched your original podcast when you first talked about light before harvest about a year or so ago, I really think it changed the end result of the plants. They all have been fire. I currently have a run thats 7 weeks into flower, 3 ATF, and 1 grape pie from seed in my 4x4, and 3 monster cropped clones in my 4x8 of 2 grape ape, and 1 alpha blue. I will be doing light before harvest on them all.

For decades I've noticed that the plants get really smelly and juice right before the light cycle because they know they are about to get blasted with light so that is my cut time. I've tried all the other things.

Totally makes sense the plants use light for photosynthesis to grow. Next harvest 24hrs light before harvest. Too bad I don’t have 2 tents to test side by side.

Yes 60 degree in the end

Much respect😎👊

Great video

Of course the plants must be resilient I’m relying on humidity levels in My Home had no issues recently with eight moved it under my electric sky 300 es in a 2.4 Taking up most of the space sure the heck beats running my mega light pro for one plant took down 7/ Experimental that’s what it’s all about Giving my last gelato on week eight going on straight filtered water molasses and then I will chop week 11 Feeding organics I could probably just give straight water more colors and density Each day East Coast humidity levels are below 60 which is efficient I try different things and each time they work out very well I do use TPS billions a couple times a week just to give that beneficial Health Last stages excellent for veg Thank you for the input

Ah, the ol' 48 hour freakout. As I like to call it 😂

Good one

Make sense because they make the terpenes and all that fun stuff while the lights are on

When I did my first grow I didn't do any darkness and buds came out great, I'm on my 2nd grow

He’s right

Been doing this my last 3 harvests. 48 hours of light and I lower my temps to low 60s. Results have been great for me.

Bugbee is the goat

Best regards. Thanks for your information. Any thoughts on using a combination of LED light s pectrum with a 450 Watt Metal Halide for Veg. Then HPS for Bloom.? Transformer has dimmer capacity. Or would you think a full out LED set up would bring better results? Once again best regards and appreciate your thoughts on this combination?

I do 24 hours of light immediately following up with 48 hours of darkness. I also Stab the bottom stems with toothpicks before 24 hours of light. I also reduce the temperature 🌡

Interesting... I'd agree with temperature.. Not sold on the light part... plants create sugars and energy through photosynthesis, yes, but they also use a respiration cycle. Might have to try this!

What do you think about harvesting before the lights Turn on ? something about sugars and stuff That go down into the soil at night.

It's cool to listen that just at harvest i try this technik 24h or 48h of light before the cut ? Stay safe peace

a week before harvest ,i gradually work up to a 15 hr, full light. till harvest. And I do harvest before the sun comes up.

I see Mr.grow doing this fornhis nxt experiment

If im not mistaken the crystals is the plants sunblock and that extra uv light will help promote more resin in plant..

Just like in nature, dropping temps plenty of light

I run a perpetual and change the lights back to 18/6 when I put the next round in, it usually takes me 3 days because I take the tops first then the mids and lowers on the last day. I've seen a difference in the size of the next level overnight, it actually surprised me the first time. Didn't think anything of it though because I do it out of necessity. The only thing is most cultivars will start putting out bananas, but they have no time to mature so it has never caused me to get seeds.

Going off the interview with Bugbee and Shane from Migro. I started experimenting with high par on seedlings a month ago. First group were under 450-550 PAR for the first week, second group were started under 550 to 700. After one week the second group were as tall and had thicker stems than group one, after week 2 they surpassed the first group. Since I increased the lighting, I also increased how much I would feed by 50%. I started feeding both groups at the same time group one on day 13 and group 2 on day 6. In addition I took 4 clones 2 weeks ago ran 1st week at 350-450 PAR and 2nd week at 650-700 PAR. They were fed starting day 7 and out of the dome by 12 days. All survived and have put on new growth. Clones were struck in soil with amendments. No additional CO2 was added to environment. Wondering if anyone is working with these kind of numbers and what your results were.

I would think more then half the things advertised online is incorrect about this trade and a lot of things that have not changed for thousands of years as well.

Uv light in the dark w cold temperatures would push 2nd metabolism?

So I just tried this. I had seen a video with Dr. Bugs Bunny before about 48 hrs of light. Did it work? Who knows. Did not seem to hurt. Buds so sticky its hard to handle.

Damn. That makes sense. Idk about 24 hrs light though. Next run I won't do 48 hour dark before harvest

I have harvested both ways, I still like the way it comes out with Darkness I only do about 24 hours to 48 hours max also the cold and darkness I think makes the terpenes stronger for some reason

Won't they have stored energy from when they were in the light?

I do this with my autoflowers and it seems to help with some extra last minute resin production

Such a beautiful fractal. I fully expected this to be a religious video...and it WAS! Wonderful

About 2 hours into lights on is the cut time. Remember light decreases from either side of the day and temperature reduction is natural.

Makes sense as we want to give the plant as much light as possible for more growth and development. We flip to 12/12 because we need to trigger flowering, and compensate for the fewer hours of light by moving the fixture closer and/or turning them up towards the 1000ppfd range. This is one of the reasons autos are so good. I've got a Wedding Glue auto 6 weeks into flower on an 18/6 cycle, and the extra light really makes a difference, imo.

Im a bit confused, in my understanding the whole reason for 48h darkness is to speed up the process to reduce Chlorophyll, which will ofc make the taste and smoke better + reducing temp to keep the terpenes in a good state

So what if my autos have been 24hrs their whole life? Wouldn’t 48hrs dark be more effective in that case?

But why outdoors they harvest in the morning is for the cold temperature

If I were to do a study to gather evidence over quite literally any topic as an amateur , and asked as many others to participate in it as I can for a corroborative study, no matter what we find people wouldn't call it "evidence" even though by definition that's exactly what it would be. We could literally write our findings in a report and send it to scholarly publishers and be nothing but denied given we aren't directly involved with said publishers. We live in a world where the only evidence we are allowed to have is what the people that control the markets want us to have.

WHAT ABOUT PUTTING PLANTS ON48 DARKNESS TO JUMP START FLOWERING????

isnt it like this: carbohydrate and chlorophyl starts decaying when darknes is setting in? so the flavour of tha herb could be better when the chlorophyll and carbonhydrates get decayed by more darkness than the day before? if somebdy has any science based knowledge on this exact topic pls lemmeno

So its not a matter of whats fact and whats fiction? The argument is: Is it better to preserve terpenes? Or to allow the plant to create new terpenes? At the end of its life, that is. I see so many people quoting this video without actually understanding the point hes making.

I'd ask the question "what if we're supplementing the plant with bioavailable sugar?"

Just a thought.. what if you do lower temperature, 48hrs lights on then 24hrs off b4 harvest?

Interesting; as a follow-up, I wonder what time of day is best to harvest then. I've heard ppl say that just before dawn is the optimum time , or least before the heat of the day has hit the plant. Now I wonder if the evening isn't better.🤔🤷‍♂️ ✌️💚🌲🌏☮️🕊

I do 72 hours and giving her water in the first day and taste is wonderful

I've found 48hrs of darkness makes the purples and reds more prominent than running 12/12 up to harvest, even the hairs on the buds are noticeably more vibrant looking. After curing you'd think it was two separate strains. I believe this is a matter of contrast due to the buds being a lighter shade of green as a result of less chlorophyl. This is with cuts from the same mother grown, dried and cured under identical conditions. The smell, flavor and effect seems identical to me though.

I always reduce temps even in veg, i go no more go then 73 degrees even in flower. I get high potent buds. Last time i checked the thc levels it was in the high 20s.

what about the increased degredation of chlorophyll? if there's no more light to drive photosynthesis, wouldnt a plant use its remaining resources to make new roots? using the many nitrogens tied up with carbons and the 1 magnesium atom to make up chlorophyll? id say thats desirable for cleaner smoke if youre going to consume the flower

@gardentalk have you tried this yet with lab results for comparison or is this just a quick reiterating of Bruce's advice?

I watched alot of vids but found DR Bruce and wow ! the level of what can be down growing and the knowlege this man has amazing and to share with us is something else and i did 48 Light and the plant looked hmm more stronger vibrant whiter it just looked better looks louder than when 48 hr dark plants looked drained flat quiet if that makes sense i can see the differance in light or dark hang its is the simplest way to explain the results for me lol and 48 hr light is what i use now on unless outdoor grow thats whole other game lol

The light will make more protection

The cold sprebemtd it from evaporating if u did a good job your turpentine is there and slow dry is natural dry which is what u need for perfect flavors 60 °f 60rh% 60 day cure only I had it dry ten days full taste smooth smoke after a week of curing it was the cold that did it

When I harvest my plants they are done with producing terpenes or trichomes. I switch off the lights 48 hours before cutting to pre-cure the plants. If the plant is getting no more light she can’t do no mir photosynthesis and won’t produce any more chlorophyll, what I don’t want to have in my flowers

I love when people back up my theory...been saying this for years.

I like the fact that this is a suggestion based on best practices for plant care, especially regarding cannabis and that it is from an actual Doctor in the field. I understand there is little to go on, but 48 hours of darkness sounds like broscience and not real science. There needs to be more work done to study the differences. Pre and post testing of potency. 48 hours of dark vs regular 12 hour light vs 48 hour light. That way we can see for sure what is best.

I thought you did 2 days darkness to get rid of as much chlorophyll as possible.

What if we put them in 48 no light for stress then 48 of light to produce?

Yes it is fact that temperature is one of the keys. Plants have had to deal with temp swings throughout the entire genetic code, all the way back to the very first cannabis plants. This has embedded a genetic physical response. Nobody has taken the sun away or stoped the earth from turning. I dont think the plant has had enough evolutionary development with round the clock light or darkness. So in my opinion we should really be looking for these 1 in 200 that show increased reaction to light dep or the other. If it does indeed influence a desired reaction from the plant then the breeder's have another fun project to potentially coax out of our wonderful lady's. Just an additional thought. What if this isn't creating new terpenes but the low temps are preserving more of them that would otherwise off gas. That would seem as if more developed but wouldn't actually be the case. You've just preserved more already existing terps. Kinda like topping creates more tops. 🤔 Nope, those two nodes already existed topping didn't "create" new anything. It just got the top foliage out of the way so those existing 2 nodes are now in direct light. LST and bending the top down to a horizontal orientation expose these nodes just as topping would. However, you dont endure 2 or 3 days of stunted growth. Outdoor is the only method I see to be efficient for topping. It doesn't cost anything to keep the sun on, accumulate all the days of stunted growth depending on how many times you top, it can add up. Indoor especially commercial this can get costly over a course of time, every minute she doesn't grow she's just pushing your harvest date further. This is a reoccurring and accumulative deficit of time which is an expense. I'm personally intrigued about what possibilities may await concerning common allergies to pollen ect. Very exciting future ahead nonetheless!

I do 72

Great content once again. So, should we then be harvesting at the end of a light cycle, or at the beginning of a light cycle? Or does is really matter? Based on this information, it seems like it would be best to harvest while the plant is in full production of turpines and trichomes. Not after 12 hours of loosing turpines and trichomes during the dark cycle. Thoughts Chris?

I have an interesting question/theory. I have the UV lights built into my light and I’m curious as to what would happen if I did 24-48 hours of straight UV before harvest. Anyone ever tried this out?

When you put the plants in dark, they use their carbohydrates reserves. They have reserves build up for 1-2 days. So the gentleman is not quite right about what he says regarding this. After the reserves are used up (aprox. 48 hours) the plants use the proteins of the chlorophyll complex to generate new energy and that is exactly what we want. We want the plant to metabolize the chlorophyll. In that process a lot of secondary plant substances are generated and that is exactly what makes the plant e.g. yellow, red, or even bluish. Putting them in darkness only starts the process that would have been starting anyway while drying AND reduces temperature which avoids the evaporation of terpenes - there he is right. So try for yourself and find out what the best method might be.

1:00 - Would this also mean that defoliating during flower is a bad idea? I remove big fan leaves to expose other flowers to light. Not good?

Mr grow it could you talk about light in the transition from veg to flower , I just had a major seed company tell me I should take 1 hr away till I get to 12/12 could just switching strait to 12/12