mrgreen2015
Well-Known Member
PART 1
Numero Uno
The first, and perhaps most important, aspect of harvesting cannabis is knowing exactly when to start chopping down the ladies. A precision harvest is essential for potent cultivation. Growers must be very careful not to cut down plants that are not yet at the pinnacle of resin production, but they must also be wary of cutting plants too late—at a time when THC production has curtailed and resin glands begin to degrade.
There are various methods by which even the most amateur grower can tell when buds are truly ripe for the picking. The simplest and quickest way to know is by examining the pistils, or long hairs, that cover the plant’s buds. At the onset of flowering, these pistils are white and stringy. But as the flowering period comes to an end, they begin to turn color, first from white to orange and then again to a dark red or brown. These color changes signify the maturation of the buds; however, the color and time frame may vary significantly across different varieties of cannabis.
Therefore, a better, yet slightly more complicated, method for determining ripeness is through trichome examination. Trichomes are the actual resin glands that contain THC and other psychoactive cannabinoids, and they are very delicate and easily ruptured. These trichomes are visible on the outside of buds and small leaves and look like little white sugar crystals to the naked eye. However, with the power of a magnifying glass or simple microscope, you can see that trichomes are comprised of a stalk and resin head and are clear or white in color.
As with pistils, trichomes also begin to change color as the buds mature. But in this scenario, a grower wants to harvest buds before they get too dark in color. Even a subtle amber hue in these glands could mean that cannabinoids have begun breaking down and decomposing, which means less potent pot. Using a magnifier between 50x-100x, advanced growers look for a creamy or milky white color in trichomes that tells them it’s time to harvest.
The Catch
As with most tricks of the trade, there is always a catch. And in this case it can be taken quite literally as well, because when checking your buds for ripeness you’ll want to “catch” any and all clues that can signal maturation—a few weeks before harvest time. Having a “harvest heads-up” can be extremely beneficial for growers, not only to prep equipment and rooms for drying and curing, but also to prep the plants for taste and smooth smoking.
If a grower can consistently examine trichomes and keep accurate time records from the start of the flowering photo-period (12/12 light cycle), then it should be no problem for the grower to begin flushing out the grow medium in preparation for the harvest.
The Two-Step Flush
The last two weeks of flowering should be spent getting rid of any built-up nutrients in the growing medium, a process called leaching, or flushing. By removing all access to nutrients, the plant begins to consume its stored food reserves. These reserves are nasty compounds that we don't want in our smoke, such as sugars, starches and various other elements. Harvesting plants that still have these undesirable elements present will only result in a harsh smoke and terrible burnability.
Flushing should begin about 14 days before harvest by stopping all nutrients and using only pure water to feed the plants. By providing no nutrients, you force the plant to rely only on what is left in the growing medium to feed on. The actual act of flushing is achieved by over-irrigating the medium until the nutrients inside are dissolved and washed out the bottom of the container. The best way to do this is with a two-step flush technique. (The process is an easy one.)
First, flood the grow medium with a heavy dose of water and wait a few minutes to allow all of the salts (nutrient buildup) to break down. Then add more water to chase out the first dose. By waiting a few minutes after adding the first dose of water, you're allowing enough time for the water to dissolve the salts. As salts decompose, they can be effectively flushed out by the second dose. Traditional leaching usually employs only the first flush of water, which isn’t always adequate for complete dissolution.
A few days after flushing, you should notice signs of nitrogen deficiency. The leaves will go from dark to light green, eventually turning completely yellow. Another sign is a reddening of the leaf stems, starting at the center of the leaf where the blades come together.
Test your flush by snapping off a leaf and tasting the juice that flows from the stem. If the taste is bitter, there's still plenty of food in the plant's system. When the juices are clean and taste like pure water, the plant is clean enough for harvest. The bitterness is from nutrients and other chemicals that you definitely do not want in your smoke.
Dry Air = More Resin
One final flush should occur a day or two before harvesting, with the final 24 hours of the garden’s life being spent in relative dryness. This last deluge should be done with fresh water and can be a single or a two-step flush, depending on how much fertilizer was applied previous to the final two weeks of flowering. This will be the final watering your plants ever get. In doing this, you help ensure that the plants will begin to slowly dehydrate as you approach harvest, which in turn will aid the plants in their final hours of resin production.
Some gardeners even like to allow their medium to go bone-dry before harvesting. The idea is that resin production seems to skyrocket if the medium is allowed to dry before harvesting, but this isn't due to dry medium – it's due to dry air.
When the relative humidity in the garden is low, your resin production will increase. This is a natural response cannabis has to dry air, an attempt to protect itself from hot, dry conditions. Marijuana resin actually has one of the highest UV-resistance ratings in the plant kingdom. The resin reflects light, preventing the buds from getting sunburn. (This is also why it's so easy for helicopters to spot marijuana from the sky; it glows when seen through UV-sensitive equipment.)
Lowering the humidity in the room on that last night before harvest morning will ensure increased resin production, without having to let the medium go bone-dry first. Additionally, some growers like to subject their gardens to prolonged dark periods of up to 24 hours just before cutting, claiming they notice spikes in resin production. This is all right as the low humidity will cut down on light uptake anyway, plus it helps to make sure liquid foods within the plants drain down to the root zone.
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