Determining Harvest Time

I recently havested my 8th Indoor Hydro Grow, and I wanted to share what I have learned. I hope this information is helpful, and simple to read and understand.

This is a discussion of HARVEST TIME of Indica, Hydroponically grown indoors. Determining Sativa Harvest Time is much different.

From experience of growing the same two Indica strains many times, I know more than 8 weeks and a day less than 9 weeks of Flowering will be a great time to harvest my Indica as well as most other Indicas. I start counting Flowering Time the day I change the Light Cycle to 12/12.
But what if I did not have any experience?

In the old days of growing outdoors, we harvested when the weather man told us the first frost was coming. What we were really doing is harvesting when the plant and buds became FULLY MATURE. But how do you determine that? How do you know the buds are RIPE AND FULLY MATURE? How do you actually determine the right time to harvest?

Some growers say go by the calendar and count the weeks of 12/12. That will work OK, but it is not an exact science. Some growers buy seeds and harvest by the suggested Flowerig Time on the seed packet. That is a good
2nd rule of thumb.

And then there are those that harvest by the color of the so-called hairs, or pistals. For the first 7 or 8 weeks of the Flowerig Cycle, we see white pistals. Then, just overnight it seems, we see a darkening of them, a reddening, or some say a browning of the hairs. They do change from white to red to a very dark near brownish-red color. Many growers harvest by waiting until the majority of the pistals on the upper growth of the plant turn about 75% red, and then they harvest. That will work too, although still not very scientific.

The most scientific logical practical time to harvest is determined by the trichome color.
Trichomes (the trichs) are what we used to call the "crystals" or "diamonds" or "sparkles" that we see on the trim leaves very near the buds. In Europe, they are called the resin glands.
Trichomes are very sticky, almost like fresh model airplane glue. They stand tall, looking like a phallic symbol. Some have large heads like a tall skinny muchroom, and some do not. Some appear like a golf ball sitting on a T.
They are easily viewed with a cheap magnifying glass.

Let me show you a few pics of trichs taken with a microscope.

Trich_Pic_3.jpg


Trich_Pic_1.jpg


Trich_Pic_2.jpg



Here you see some trichs on some swollen calyxes:
Trich_Pic_4.jpg

You can also see the pistals changing from white to red and reddish-brown.

(trich pics supplied by C5Rftw)
 
Re: Roseman's Determining Harvest Time

Other than the Trichome color and counting the weeks in 12/12, you should also determine harvest time by:

When the Calyxes are fat, swollen and plump, looking like they contain seeds.

When about 80% of the pistils have turned reddish brown.

And Very Important, when the new pistil development has come to a crawl suggesting the plant is at the end of its life cycle.


Why does the plant have trichomes?

Trichomes are on the plant's flowers to deter insects.

They are there to hold moisture in, to collect humidity, and to warm the plant from the cold.
(Suggestion: Chill the plant or grow-area to increase the trichomes)

Trichomes are there on the flowers and young trim leaves to prevent mold and fungus.

Trichomes are supposed to taste bad to animals, although most cats loves them.

Being sticky, the Trichomes catch the male pollen.

And best of all, Trichomes are where the THC is stored and concentrated.


This is the most popular trichome chart available for determinging Harvest time.
Trichome-Ripening.jpg



You can easily tell by the chart, that you do not want to harvest while the trichs are still clear.

Trichomes begin CLEAR, then get CLOUDY or MILKY, then they get AMBER colored.

When the trichs are the color of male semen, a milky cloudy color, the buds will give a HEAD HIGH, similar to a HASH High.

When the trichs are the color of Heineken Light Beer, or what we jokingly call BUD LIGHT , the High will be a couch lock high, a sleepy high, or a numb high, the one most desired for medical reasons.

And when the trichs are half and half, the High is both half heady and half body high too.
 
Re: Roseman's Determining Harvest Time

So how do you look at the trichs up close?

I spoke to a grower today who uses a telescope turned upside down to look at them. Some growers use a large magnifying glass.


A good Magnifying glass works great.
Magnifyig_Glass_2.jpg


Magnifying_Glass_1.jpg
 
Re: Roseman's Determining Harvest Time

I bought this battery lighted microscope at Radio Shack three years ago, for $11.00. I think it is $13.00 now. I like it best.

Scope_Pic_2.jpg


And this one is easily found on the Internet for twice the price.


Scope_1.jpg


With the smaller microscope, it is easy to cut a sample of a trim leaf off, just snip the tip off. Then you take it to the kitchen table, holding it with tweezers, laying it on a white dinner plate to examine it. To learn how, seek the edge of the leaf. After you get the hang of it, and get some practice in focusing the microscope, it will get much easier to do.
 
Re: Roseman's Determining Harvest Time

Hey Roseman, thanks for the info, as you know it's just a matter of a couple of weeks until I'm using this knowledge. This leaves me enough time to order one of those microscopes from Radio Shack! I've got a magnifying glass and a photographers loupe, but they don't seem to get me close enough to the trich to see the insides, I need more POWER!

Thanks again man, your timing is perfect! I can't believe it but every time I need information there it is, in a new tutorial by Roseman.
 
Re: Roseman's Determining Harvest Time

Really great info Roseman!

I wonder if you have any experience regarding letting plants dry out before harvesting? I've heard this mostly regarding soil, but I would like to try it for 24hrs combined with a 48hr dark period: just drain the res completely out (I use DWC)

Any opinion on this? Think it makes thichromes multiply? Or just mature them faster/more evenly?

Thanks :)
 
Re: Roseman's Determining Harvest Time

Nice thread Roseman, very accurate info. All of the methods work well and I'm sure what ever one you use you'll harvest roughly the same time you would with another. The plant always tells you when to harvest with it's ever changing characteristics.
 
Re: Roseman's Determining Harvest Time

This is a jeweler's loupe, for looking at precious stones, and it works great for looking at trichs.

Jewelers_Loupe.jpg




And this loupe is used to look at 35 mm film or photo slides.

Film_Loupe_2.jpg

That jewlers loupe is the same one I have and it does a pretty good job but wouldnt you agree if it was bigger in diameter it would really be the shiznit! :Rasta: im going to look for one
 
Re: Roseman's Determining Harvest Time

Really great info Roseman!

Thank you.

I wonder if you have any experience regarding letting plants dry out before harvesting? I've heard this mostly regarding soil, but I would like to try it for 24hrs combined with a 48hr dark period: just drain the res completely out (I use DWC)

Any opinion on this? Think it makes thichromes multiply? Or just mature them faster/more evenly?

Thanks :)

I have not done it, but I have read a lot about it....about draining the reservoir tank DRY the night before harvest. They say a 12 hour DRY period will sppeed up the Drying process AFTER they are harvested. AND they say a 24 to 48 hour dark period will increase trichomes before harvest.
I have not tried it but I have read it enough to suspect it is true.
 
Re: Roseman's Determining Harvest Time

hey im going to experiment drying out one of my res just to see the difference should be within next week or two
 
Re: Roseman's Determining Harvest Time

So THAT'S how you do it! I bought the radio shack microscope and, like a newbie, tried to examine the trichs by holding it up to the plant. DUH, gee it's hard to focus. :icon_roll:cheesygrinsmiley: Anyways, thanks Roseman. I've been at this for almost a year and learn something new all the time. I wish I had a mentor with whom to interface directly, but this forum is very helpful none the less. Cheers.:peace:
 
Re: Roseman's Determining Harvest Time

:nicethread: Roseman! +Rep and 5 stars! :bong:

I've got one of those 30x microscopes from Radio Shack 10 years ago and have found it invaluable for keeping an eye on those trichs and identifying nasty little invaders.

I'd like to get one of those USB microscopes that go up to 200X but then I'd need a laptop or a looong USB extension cord! lol

c'ya.

:peace:
 
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