From A Digital Microscope
Click on any of the images below to get an enlarged view of that photo.
Images 1-3 were taken with a digital microscope roughly 31 days after the plants from this crop had started flowering.
The marijuana plants being grown are from a mainly indica, roughly 80% indica with 20% sativa heritage, indoor strain.
The crop will be harvested at 56 days, 8 weeks, after it started flowering. There are 25 days left until harvest.
Some of the round heads on the trichomes are clear, others are starting to turn a cloudy milky translucent color.
None of the resin glands have got to the point where they have started to turn light brown.
Images 4-6 were taken, of the same crop, 56 days after the plant had started flowering. This is the day the plants were harvested.
Almost 100% of the round heads on the trichome resin glands are a cloudy milky translucent color.
There are a few of what look like yellow/brown blobs in image 4, these are trichomes starting to take on a light brown color.
Even though the trichome stem is still clear on most of the trichomes in images 4 and 5, the round heads on the top of the trichome have almost all turned milky translucent white.
A few are still clear or partially clear. Remember to judge the color of the round heads on top, not the trichome stem, to help determine when to harvest.
Images 4 and 5 represent what about 2/3 of the larger buds on the plants in this crop looked like at harvest time. Nearly all the trichome heads were cloudy white and less than 10% brown trichomes.
The other 1/3 of the larger buds from same plants in the same crop were covered with up to 20%-30% brown trichomes, with one or two buds showing a higher percentage.
The bud in image 6 is the worst example from this crop with about 50% brown trichomes. This will give you some idea of the of variability within the same crop.
This crop was harvested at 56 days, or 8 weeks, and had the characteristics that the patient who received the marijuana requested.
For someone who was smoking it and was interested only in the strongest head buzz possible, this crop could have been harvested a bit earlier, when more of the trichome heads were milky and less were brown.
The breeder who created the indoor seed strain shown in the images on this page recommended harvesting with a flowering period of 52-60 days, or 7.4 to 8.6 weeks.
After working with this mainly indica strain for a decade it has been harvested at various periods between 42-70 days, or 6-10 weeks after it has started flowering.
When smoked, the marijuana produced these effects:
42 days - strong speedy head buzz, small harvest.
49 days - strong head buzz/moderate body stone.
56 days - balanced head buzz/body stone.
63 days - balanced head buzz/body stone.
70 days - less head buzz, more sedating body stone.
The difference in effects from harvesting a week earlier or a week later is subtle, but noticeable to knowledgeable consumers.
Recreational smokers usually prefer the weed from this particular strain when it is harvested between 42-56 days. That would be expected because that is when the THC level is at max.
The marijuana harvested at 70 days after flowering sounds like it wouldn't appeal to most smokers, but a suprisingly large number of recreational and medical consumers like it.
In most cases the people who like the 70 day harvest stuff still prefer smoking the strong head buzz stuff that was harvested at 42-56 days.
When eaten or consumed in a similar manner like drinking, the marijuana from this strain is most effective for medical, recreational, spiritual consumption when the plants are harvested after flowering for 49-63 days.
The trade off to harvesting the plant earlier is a smaller harvest size. The trade off to harvesting the plant later is the THC content decreases, so the marijuana is a bit less potent.
By working with a strain you like over a period of time, you will be better able to determine the optimal harvest time for your needs.
Images on this page were taken with a digital microscope. Instructions on how to use it to monitor marijuana trichomes are located here.