The question of when to harvest tenderly cared-for plants is a question that puzzles many new growers. Most
farmers' goal is to pluck the fruit at the exact moment when the potency of the bud is at is peak. Realistically, the
skills needed to detect the specific day (or even hour) when a plant is at its peak can only be acquired through years
of experience. However, even the novice grower should be able detect the window of time during which the harvest
results in premier crop of outstanding bud.
0) Maturity and THC
Although some growers are interested
in fiber content, most people consider the plant to be mature when the percentage of THC found in the plant reaches
its maximum. It is not practical for the average grower to actually measure THC in a plant, as the chemistry is somewhat
complex. In a growing plant, each successive pair of leaves contains more THC than the previous pair. The
budding tips of the plant contain the most THC of all. Both male and female plants contain THC. In fact, some research
has shown that in the early stages of growth the males actual ly contain more THC than the females (Frank and Rosenthal,
Marijuana Grower's Guide, p. 66). Even conniseurs believe it is worth cutting and sampling shoots before the THC has
reached its maximum. Clarke suggests that the best bioassy for pot is to roll joints of several different strains,
invite all your friends over, and see which pile of joints disappears first (Marijuana Botany, p. 94)
1)
Plant Size
The size of the plant has little to do with its maturity. Outdoors, a plant might reach a height
of over eight feet (2.5m) and still not be ready for harvest. Indoors, mature, budding plants can be under 18" (.5m) high.
2) Photoperiod - The Key to Maturation
The chronological age of the plant has little to do with its maturity.
How quickly a plant matures is mostly dependent on the amount of light the plant receives each day (photoperiod).
Typically, a plant will transition from the growing (vegitative) stage to the budding stage when the light per day drops
below 12 hours. This is not to say that a 3-week-old seedling will begin to bloom when the light is cut. As
a general rule, a plant must be a minimum of 60 days old before it is mature enough to respo nd appropriately to decreased
light. For indoor growers, the decision on when to cut the photoperiod depends on available growing space, as well
as the need to harvest weed. Some growers report that clones (cuttings) can be forced to bloom prior to 60 days
old, perhaps since the cutting itself is somewhat mature at the time it is rooted.
3) Male Versus Female
Almost
always, male flowers will show prior to female buds. Thus, once the males in the garden are detected, you can be
sure that that the female budding process will start soon - usually within 1-2 weeks.
4) Different Varieties
Many
gardeners report that certain cannibis varieties take longer to mature than others. In particular, the narrow-leafed
Sativas are said to take significantly longer to initiate and complete budding, as compared to the wide-leafed Indicas.
Under some conditions, Sativas will require an additional month or more to mature after the Indicas have been harvested.
5) Time of Year
Obviously, indoor growers cannot use the seasons as a guide to harvesting (though a
cold winter-time grow room can significantly retard the growth of the plants). Outdoor growers on the other hand
can use the seasons as a predictor of the ideal harvest t ime. In the Fall, once the length of day drops below
12 hours, the count-down to harvest will be begin. Weather conditons will affect the exact harvest day from year to year,
but generally you can expect to harvest within the same two-week window each year. If you can avoid it, don't
harvest during or immediately after a rainy spell.
6) Monitoring Buds
The best way to tell if the plant
is ready is to examine the bud. In the paragraphs below, the terms "pistal" and "stigma" refer to the white hairs in
the center of the female bud. The term "calyx" refers to the pod that would surround the seed (were the plant to
be fertilized). Many growers elect to pick each bud individually, as it reaches it prime.
"Buds are at their
peak potency about one week after flower formation slows...Harvest the plants when about half the stigmas in the buds have withered...
When the plants are left in the ground, the resinous qualities of the plant may become more apparent. The bracts
and tiny leaves may swell in size...The resin content of these buds may be higher, [but] the grass will smoke more harshly
than if the buds were younger when picked." Frank and Rosenthal "Marijuana Growers Guide" pg 289, pg 295.
"In
the primordial calyxes the pistils have turned brown; however, all but the oldest of the flowers are fertile and the floral
clusters are white...Many cultivators prefer to pick some of their strains during this stage in order to produce marijuana
with a clear cerebral, psychoactive effect." Robert Connell Clarke "Marijuana Botany", pg 140.
"Eventually
the pistils start to turn color from pale white to red or brown...When the glands have swelled and the pistil has receded
into the false pod, the bud is ready to pick." Ed Rosenthal, "The Closet Cultivator", pg 100.
"At the
peak of florescence, all but the oldest of flowers have white pistil development...Another indicator is bouquet.
When a plant is at the peak of florescence, it has a sweet and musky fragrance. Later, it loses the sweetness."
Kayo, "The Sinsemilla Technique", pg 125.
"The best way to harvest is to examine the resin glands on each bud.
As they turn from clear to amber, that is the optimum time to pick. Buds usually mature from the top down, if
grown under artificial light, and you will end up with more high-quality p ot if you pick each bud when ready. However,
the plant will not just continue to produces buds at the same rate. Like any other plant, the flowering cycle lasts a specific
period of time. If you wanted a further harvest of buds, the plant would need a second cycle of vegetative growth. This
can be achieved indoors by simply turning the lights back up to a 24 hour cycle for a few weeks. Outdoors though, you
are dependent on the seasons. Frost and long nights will usually kill the plant. Of course, such a strategy
is only variable if growing a few plants. If your operation runs on an industrial scale, just drive
the combine harvester through the field."
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