Harvesting Marijuana

Parts of this article are small excerpts from Jorge’s new book, Marijuana Outdoors: Guerilla Growing, 152 pages, 60 color photos, 5.5” x 8.5”, $14.95. Copyright 2000.

Available in English, German and Spanish.


“The hardest part about harvesting is waiting until it is ready. Even after growing for more than 20 years, it’s hard to wait until the buds are completely ripe to harvest,” said Felipe a homegrown Californian. “That’s why I sacrifice one or two plants for an early harvest. This way I get early smoke and don’t hack down the crop too early.”


Harvesting a crop outdoors requires keen planning and is often more risky than harvesting indoor crops. First and foremost, persecuted gardeners and their gardens must survive police search and (asset) seizure task forces plus opportunistic thieves. If the hybrid seedlings and clones survive the cops and robbers, the resilient, abuse-tolerant plants must endure insect and fungus invasions, peppered by gusts of wind, pounding rain and animal attacks before peak potency can be determined.


To harvest an unseeded female crop, sinsemilla, non breeding males are removed as soon as spotted, dried and smoked. Breeding males are left in the ground to pollinate female plants. Seeded female crops are left in the ground until seeds rattle in the pod.


Harvested leaves are some of the first rewards growers reap. Once large leaves are fully formed, THC (tetrahydrocannabinol – the active ingredient in cannabis that gets you high) has generally peaked out in that leaf. Healthy green leaves retain peak potency. Pick leaves if they show signs of disease or rapid yellowing that fertilizer has failed to cure. Once they start to yellow and die, potency declines. Large fan leaves often yellow just before tops are ripe.


Marijuana increases in potency as it grows older. Dominantly white hair-like pistils grow from unpollinated female seed bracts, signaling a notable increase in potency. Potency peaks out 8 to 16 weeks later. Desperate growers pick early smoke by pinching off more potent growing shoots or less potent leaves. Other growers remove entire branches or plants. Pinching off tops diffuses floral hormones, sending them back to lower branches. The increased hormone concentration signals lower branches to grow taller. Snipping tips also initiates a new set of branches to grow below the cut, but does not increase harvest weight..


The size of the plant has little to do with maturity. Outdoor plants might reach a height of over ten feet and still not be ready for harvest, or be in full flower when only a few inches tall. Check out photo number one ?????. This plant is more than 4 months old and ready to harvest.

Healthy plants yield a heavy harvest. Stressed mutilated plants may produce more resin, but overall yield is lower. Marijuana needs water throughout life. Withholding water to stress plants before harvest should only be done during the last few days, if done at all.



When to Harvest

While pressure from cops and robbers can force an early harvest, so can weather. Watch weather reports for freezing cold fronts. A mild frost (temperatures of 31 – 32 degrees F. for an hour or two) or even temperatures down to 35 degrees F. will slow growth for several days or longer. A killing frost (temperatures below 31 degrees for more than two hours) can wipe out a crop. Frozen plants look and smoke like boiled spinach. If there is an early light frost when buds are small, growers often gamble and let the buds finish maturing rather than harvesting a small quantity of premature bud.

Cool damp conditions encourage gray mold fungus (botrytis) and force an early harvest. Gray mold appears as dark powdery areas near the center of dense buds and spreads quickly in humid slow moving air. Once there is a trace of gray mold, cut out and throw away moldy bits. Sterilize tools and wash hands to prevent spread of mold.

Avoid harvesting in the rain. Excessive moisture is the perfect environment for fungus. The dryer the plants at the harvest, the better.

Harvest plants in farmers’ fields before the farm crop. Find out when farmers harvested their crops last year and when they plan to harvest this year. Planting early-maturing varieties is smart. Get a copy of the local hunting regulations and talk to residents to find out when hunters roam the fields so you can avoid them.

Immediately moving the harvested crop to a safe drying location will ensure minimum damage of delicate buds. If the freshly cut cannabis is left in a wet bundle for more than a few hours, chances of mold increase exponentially.

Harvesting at night limits exposure to hikers, hunters and snitches. Wary growers find out when the police change shift or are out of the area and harvest at that time. If a local snitch calls the police, it will take more time for the officer to be dispatched to investigate. A sharp pocket knife will reduce the amount of material growers must carry at harvest time. Some growers remove large fan leaves a couple of days before harvesting to speed transport. Loading the harvest in a backpack facilitates transport and protects the crop from detection. If harvesting several different varieties, put each in a separate bag or wrap in newspaper before packing in the backpack.


Male Harvest

Male flowers take from 2 – 4 weeks to mature their pollen bearing pods from the time they first emerge. Watch out for early openers. They continue producing flowers for several weeks after the first pods have begun to shed pollen. Once male flowers are clearly visible, but before they open, is the time of peak THC production and the best time to harvest. Even though males have much less THC than females they do have some. The THC degradation process accelerates as flowers develop and fall.

To avoid pollinating nearby females, put a plastic bag over male plants before cutting. Keep breeding males totally isolated from flowering females by moving a mile or more away. Growing males indoors under a light is the most secure way to avoid unwanted pollination.


Sinsemilla Harvest

Sinsemilla, unpollinated female marijuana flower buds, are mature from 6 – 12+ weeks after flowering starts. The best time to harvest sinsemilla is when THC production has peaked, but not yet started the degradation process.

Indica and indica/sativa varieties, tend to go through 5 – 10 weeks of rapid bud formation before leveling off. The harvest is taken 1 – 3 weeks after growth slows. Harvest in most commercial indicavarieties is ready all at once, in 8 – 10 weeks.

Sativa varieties (Thai, Mexican, Colombian and African) tend to form buds at an even rate throughout flowering, with no marked decline in growth rate. Buds at the top of the plant may reach peak potency a few days to a couple of weeks before buds on lower branches and require several harvests. Long season plants, such as the Thai ‘Haze’ can flower for several months.

Smoking, diminishing returns and scientific observation are three excellent techniques used to test for peak ripeness. Smoking is the most fun. Harvest an average bud, dry it at 200 degrees F for 10 – 15 minutes and smoke it. The smoke is harsh, but palatable. Test when straight and several times throughout flowering.

A point of diminishing returns is reached when the pistils on the bottom of the bud are dying (turning brown) faster than they are growing from the top of the bud. At this point, THC production has usually peaked out and on its way down hill. This is the best way to tell a ripe bud with the naked eye.

Looking at resin glands with an inexpensive microscope (20 – 50X) is an easy precise way to discern peak THC production. Place a small, thin, resinous portion of the bud under a microscope at 30X magnification. A flashlight or lamp will help to give you an unshadowed view of the resin glands. Portable microscopes afford a quick peek at resin glands without harvesting the bud. Look for stalked glands with the knob or ball at the top. They have the highest concentration of THC. Other hair-like and non-stalked glands or trichomes contain much less THC. Note: Resin glands rupture and decompose quickly, lowering potency, when buds are bruised. Handle buds as gently as possible to avoid premature degradation.

Draw resin glands under 30X microscope

Preference dictates harvest time. Once stalked trichomes develop a knob or a head, are fully developed and still translucent, it is the peak of an early harvest. Amber colored glands are decomposing and THC content declines slightly. Resin glands seldom develop uniformly. Therefore some glands will be changing to translucent and others decomposing. Peak harvest is when more glands are translucent than amber. Check over a period of several days and check several buds from different plants to make sure the maximum amount of trichomes are ripe for harvest.

Growers report a soaring high if buds are picked a little early, when more resin glands are translucent and a heavier more lethargic stone when buds are picked after more resin glands show amber.



Drying and curing preserve taste, aroma and the buzz of the THC. Drying converts THC from its non-psychoactive acid form to its psychoactive neutral form. Drying also converts 75 percent or more of the freshly harvested plant into water vapor and other gases.

When harvested, the THC content starts to degrade. Light, heat (above 90 degrees F), friction from fondling hands and damp, humid conditions all degrade THC.

THC is produced in the leaves and flowers. Stems and roots contain few cannabinoids, if any, and the resin is not very psychoactive. Boiling roots to extract THC is crazy and does not work. Hanging plants upside down is for convenience, not to let resin drain into the buds.

Buds dry in a forced air food preserver in less than 24 hours. A green raspy chlorophyll taste permeates the resulting fast-dried smoke. Growers who are in a hurry to smoke place a few buds in the microwave and turn it on in short, weak bursts of 15 – 30 seconds each. Recycle until dry. The smoke is harsh but effective. It will take 10 – 15 minutes at 200 degrees F. when using a gas, electric or a toaster oven. Fast-dried marijuana is raspy and harsh. Temperatures above 200 degrees F will vaporize THC.

For best results, drying should be slow and incorporate circulating, temperate (40 – 60 degrees F.), dry air. When dried slowly, over 2 – 3 weeks, moisture evaporates evenly into the air, yielding uniformly dry buds with minimal THC decomposition. These buds smoke smooth and taste sweet. Tops dried too slowly in humid air (above 80 percent) tend to contract fungus and burn poorly.

To dry, hang tops from drying lines near the ceiling in a dark room with an oscillating fan on the floor. Other growers tack plywood together to form a small room or use a large cardboard box with strings stretched between the walls to form drying lines. Circulate the air in the room/box with an oscillating fan and do not let it blow directly on drying plants, It dries them out too fast. Fungus can become a problem, especially if ventilation is inadequate. Keep constant lookout for any signs of fungus. Light hastens resin decomposition.

Light, heat and friction start the biodegradation process and after cops and robbers, pose the biggest threat to harvested marijuana. Keep dried marijuana off hot car dash boards, radiators, refrigerators, etc. Friction also destroys tender resin glands. Baggies and fondling hands rupture tiny resin glands. To keep dried marijuana in mint condition, store it in an air tight, rigid container and place it in the refrigerator. Do not keep it in the freezer, very cold temperatures combined with moisture destroy the THC glands. Canning jars allow buds to be admired and protected. Jars are very popular to contain the fragrance of pungent varieties. Some growers place an orange or lemon peel in the jar to add aroma to the bouquet, while others argue foreign substances degrade from taste.

Leaves dry very well in a paper bag. Throw leaves, shake and small buds in a shopping bag and fold the top over. Place the bag in a dry, warm place out of the way, like on top of the refrigerator or in a heated room. Check it every day, turning the leaves over. They should be dry in a week or two depending on humidity. The warmer the sack, the faster the marijuana dries, and the harsher it smokes.

Nothing equals the taste of your own homegrown smoke. Each and every toke tastes sweeter than the last. Harvesting and consuming this ancient plant reconfirms our inalienable rights as human beings. Smile and take a hit of the sweet taste of freedom!


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