Sinsemilla Harvest
Marijuana Horticulture
by Jorge Cervantes
Sinsemilla flowers are mature from 6 – 12 weeks after the photoperiod has been changed to 12 hours. The best time to harvest sinsemilla is when THC production has peaked but not yet started the degradation process. Established indoor varieties are bred so the entire plant reaches peak potency at the same time. Lower flower tops that receive less light are not as heavily frosted with resin as upper branches and could be slower to mature.
Varieties that ripen all at once tend to go thru four or five weeks of rapid bud formation before growth levels off. The harvest is taken one to three weeks after growth slows. Pure indica varieties and many indica/sativa crosses are picked six to ten weeks after inducing flowering, while indica crosses with more dominant sativas, such as Skunk #1, may not be ready for ten weeks. Commercial growers often pick immature six-week old buds so they can harvest one more crop every year.
Pure sativa varieties, especially Thai and Asian strains that were grown from native seed, take longer to bloom after turning the light to 12 hours. They could take four months to finish blooming! These types tend to form buds at an even rate throughout flowering with no marked decline in growth rate. Few indoor growers have the time or patience to grow pure sativa varieties because of their long flowering period, leggy stature, and low yields. Buds at the top of the plant often reach peak potency a few days to a couple of weeks before lower buds. Long blooming equatorial sativas may require several harvest.
Pistils turn from white to brown or brownish-red as the flower tops ripen. Pistil changing color indicates plants are turning ripe; however, it is not the best indicator of peak ripeness. After more hands n research, I have earned that it is difficult to tell peak ripeness by the color of pistils in all strains. The best gauge of peak ripeness is the color of the resin glands or trichomes.
Resin glands change colors as they ripen. At first, glands are clear. As they continue to mature, they turn a translucent milky color and, finally, they turn amber. Resin glands that are bruised from being squeezed or jostled about deteriorate quickly. All glands d not change color simultaneously on the same bud or plant. The process is gradual, and individual resin glands change at different rates. Of course there are exceptions such as the strain Blueberry, which bears darker, even purplish resin glands.
To get a close-up look at resin glands, use a 10X magnifying glass, jeweler’s loupe, or a 20-50X hand held microscope. My preference is a 30X hand held microscope with a battery powered lamp used by stamp collectors. Look at resin glands without harvesting buds, or take a small, thin, resinous portion of a ripe bud and place it under the microscope at a low 30X magnification setting. If the microscope does not have a lamp, a flashlight will be necessary for an un-shadowed view.
Resin gland development will be in one of three stages – clear, translucent or milky white, and amber.
Harvest when the majority of glands are clear and a few glands have started to turn milky white. Harvesting plants too early, before a few of the glands turn milky, will make them less psychoactive, because they hold less THC. Harvesting at this point will yield a cerebral, soaring, heady stone. The body will be less affected. Pure sativa and sativa-dominant strains are perfect for this harvest scenario.
Harvest when half of the trichomes have turned a creamy translucent color for absolute peak ripeness. At this point, the high will be both cerebral and physical with a good head and body stone.
harvest when the majority of trichomes have turned amber for a body stone. Pure indica, afghani, and indica-dominant strains harvested at this late point will possess a heavy body, or couch-lock, stone. Waiting to harvest pure sativa and sativa-dominant varieties until this stage will not take advantage of the strains. Such strains are best harvested when resin glands are clear to milky colored.