New Grower When to harvest autos? Your leaves will tell you.

One of the most frequently asked questions is how do I know when my autos are ready to pick? The convention wisdom from growing photo period plants was to watch for color change in the trichomes, or crystals. For an uplifting high, harvest when the trichomes are all cloudy, for more of a stone, wait till a percentage have turned amber. Sound advice, for photos. But autos are a little different. While some strains have shown amber trics, many do not.

So how do I know when they are ready? I watch the the fan leaves. Over the past several years of growing autos I started taking samples at various stages of growth to evaluate the high. I tend to prefer my smoke with a little stone so began to leave them longer than the 8-9 weeks that are advertised. I find that around 11-12 weeks the plants are ripe for me. I also began to see a correlation between the color of the fan leaves, the color of the trics and the high/stone quality of the smoke at the various sample intervals. It seemed that the greener the fan leaves, the more clear trics the buds had. As the fan leaves started to yellow and die off, the trics became less clear and more milky. By the time that all the fan leaves had died off and the bud leaves were starting to yellow, I got the quality of smoke I wanted. At that time most of the trics were now milky with no, or only a few, clear ones. Here are some examples:



I've found this to be a very reliable method. It takes about 3 weeks for the fan leaves to die off. During that time the buds will continue to fatten up as the plant uses the energy stored in the fan leaves. So when I see my leaves start to yellow, I wait a week, then begin cleansing them. Two weeks later they will be well cleansed and read to harvest.

Of course there will be other factors such as genetics, lighting, nutrients, pot size, etc. that will effect how long a plant takes. But as a general guide for when to pick, just watch your leaves.

NOTE: If you have questions regarding your personal grow, please post them in the appropriate forum and not in this thread.

 

[low_and_slow]

Then there's the question of "What happens to THC production/maturation once the meristem is cut?"

 

[TxOld Dude]

Watch the trichs and see. All processes continue for a limited time after the cut. Cellular death of the plant is not equated with the cutting of the mainstem. It's equated with the CURE. That's why controlling the drying and the cure is so important. Even the human body, at a cellular level, takes weeks to die. THC production will stop as the cells lose their energy and go into survival mode, but as each cell runs out of energy from stored sugars, the mitochondria (the "engine or battery" for a cell) dies. Drying is the change from life to death. Curing is slowing down the process so as to retain moisture and remaining sugars in the plant to keep it from being harsh to the taste. Some fermentation occurs during this process and creates more sugars. That's why the slower the dry/cure, the better the bud. All you oldtimers ever notice that some of the Colombian had a distinct "ammonia" smell to it? That's because it was bricked and wrapped before it was properly dried and fermented during transport with no way to vent the ammonia gasses generated. THC also degrades more with heat and humidity if the cure is not controlled and can become CBC(?) instead of CBN and CBD and ruin good smoke. Good up, but fast down and can leave you with a headache. The seed for my grow came from a batch that had this happen. The buzz was good for about 30-45 minutes, then WHAM!, straight again!

I've noticed some confusion here and on several other sites (including my own confusion as it's been too many years) on which cannabinoid does what. "This is Rumor Control. Here are the facts..."
THC = upper and head buzz
CBN = Couchlock and body buzz
CBD = No active effect, but helps regulate certain aspects of THC such as paranoia, deppresion, etc...
Hell, here's the link. A MUST READ! VERY DETAILED!
http://en.wikipedia.org/wiki/Cannabinoids

If you want to keep the THC levels at their highest, try cutting at 50% cloudy / 50% clear, which is the peak point. If you look at the trichs on a bud cut when cloudy and then after curing, I'll bet you see a lot of ambering after the fact. If you cut buds when they're ready and not all at once, then you can control your production quality.

A good newbie link for harvesting tips:
http://grow-marijuana.com/harvesting

An Experiment:
Try taking and cutting different popcorn buds at different times and watch the cure process versus trichome condition and verify how much clouding and ambering occurs AFTER the cut under controlled conditions. You could even vary the temps and humidity. Cut one clear and one cloudy and see how much change occurs during "your" normal curing method. This will help you control how you want YOUR buzz to be and even allow you to mix the result intentionally for different purposes.

Fish
:Cool:


P.S. - Sorry for the long dissertation. I'm a knowledge junkie that used to own that 5" inch thick "How To Grow Marijuana" book way back when. Read the whole damn thing cover-to-cover before some asshole stole it.
"Grrr"

 

[Muddy]

Very interesting Muddy, i know that uv is a sure fire way to get more THC production, and like you i too look forward to seeing what kind of results these new lights produce.Not sure about what Clarke says about this though, as growing under HPS produces virtually no uv, as the glass in the bulb shields the uv, so you would expect plants grown under HPS to show no ambering. But to be honest the more i read on the subject the less i now feel inclined to let them amber at all, as peak THC production happens when the trichomes are cloudy. But i think we can agree that the best way to find out if the plant is ready, is to take test samples, until the weed suits your own personal taste.

I never got any amber when I was using HPS either. I've got a little on some strains grown under my LEDs, but had to let them go almost 14 weeks before I saw any. In general I like to leave mine go long, usually 12-13 weeks, until everything is cloudy. But as you say, it really comes down to personal preference.

 

[TxOld Dude]

I never got any amber when I was using HPS either. I've got a little on some strains grown under my LEDs, but had to let them go almost 14 weeks before I saw any. In general I like to leave mine go long, usually 12-13 weeks, until everything is cloudy. But as you say, it really comes down to personal preference.

Could it have been a temperature thing then rather than the HPS? I know that cooler temps = less breakdown, but then again I'm just getting started with HID...

 

[Muddy]

Could it have been a temperature thing then rather than the HPS? I know that cooler temps = less breakdown, but then again I'm just getting started with HID...

I don't think so. Everything that I've read on the subject never mentioned temperatures as being a factor. In fact, I've had some long flowering outdoor photos that continued to amber well into Nov. when night time temps were getting cold. Indoors when I was running HPS, temps were always above 80, often higher. High heat from the HPS was the primary reason I switched to LEDs.

 

[MountainMan]

Bookmarking is the new learning. Thanks dude

:gthumb:​

 

[TxOld Dude]

Weed gets you through times of no money better than money gets you through times of no weed.

Muddy, that's my favorite "Freak Brothers" motto! :stylez rasta smoke:

 

[Muddy]

Muddy, that's my favorite "Freak Brothers" motto! :stylez rasta smoke:

Yep, an oldie but a goodie. I got that from a Freewheelin Franklin poster I had. Matter of fact, I think it might still be rolled up, sitting in the closet! LOL, it pretty much describes my current situation. No money!

 

[maenam]

Thanks very much, great post.

 

[Smeghead]

Almost harvest time and a few fan leaves are going yellow. Let me summarize to make sure I have timings down.

When fan leaves start to go yellow still continue with ferts and gradually reduce. Start picking off leaves as soon as they go brown and crispy until I'm left with only buds and when bud leaves start to yellow then we're one week out from harvest and water with just plain ph water and blackstrap molassas? I'm going for high cbd body relaxation.

I have one big yellow fan leaf now. How far out am I from harvest?

Basically I should be picking off big leaves as they go brown and about to fall off by themselves until all i'm left with is the buds as they look like in the original post?