The calyxes will swell and harden , your pistols will mostly all turn red , and the leaves will start to cannibalize themselves , turning yellow . Fourteen days is usually enough for most strains ; it is only the sativa-dominant strains that sometimes need longer . Watching your hairs or stigmas is the best way to know when to harvest as every strain and phenotype is slightly different . This method is more precise than following the recommended growing length for your seed via the breeder . This is because every phenotype is different and the seed information will be generic or based on average timelines , while every seed will take on different traits , sometimes more of the mom , sometimes more of the dad .
Takeaways :
• Flush with reverse osmosis or clean water for a minimum of 14 days .
• Watch your pistils ’ color development .
Going a Step Further
When it is just about time to harvest , you can look a little deeper into things and look directly at the trichomes of the plant with a 5x microscope , a loupe , or a good phone camera . The trichomes are small factories , creating different cannabinoids and terpenes , amongst other things . The head of the trichome will be a clear ball most of its life , though toward the end it will go through a milky white stage , then amber , and finally a darker shade of red as it begins keeling over and dying ( we don ’ t want that !). I personally prefer to harvest my cannabis when the trichome is a milky white with some starting to turn amber . It will be at high potency at this point with no dying trichomes , without too much of the couch lock that comes with the amber trichomes ( and indica strains ).
Takeaways :
• Use a microscope , loupe , or good camera to see your trichome development .
• Do not let the trichomes keel over and die ( growing past 100 percent red hair ).
Flushing Amounts
The flushing phase is not the same as your normal water feeds . You will want to feed the plants more than normal with water that ’ s as clean as possible , with zero nutrients and no pH up or down . It is not necessary to adjust your pH when flushing , as the only reason to adjust pH is so your plant takes in the right level of nutrients . This , and the fact that adding pH up or down will add PPM , or acid , to the tank that your flower will take in during the last phase of its life , which we don ’ t want either .
Feed your plants two to three times the amount of water as normal — reverse osmosis water is ideal in this stage as well as the growth stage , if you can . Do not let your run-off water sit in your trays or tables . If using recirculating hydroponics , flush out your system much more frequently than normal . This will allow the expelled nutrients built up in your root base or medium to wash off . Of course , recirculating hydroponics runoff will reach low PPM quicker than a system with a grow medium , but it is still just as important to flush for the 14 – 28-day period to allow the plant to go through the ripening process , cannibalizing its leaves , using up stored nutrients , and packing on the THC and weight .
Takeaways :
• Feed two to three times the regular amount of water in a drain-to-waste system , and flush out two to three times as much in a recirculating hydroponic system during flush .
• Allow for proper drainage .
“ Watching your hairs or stigmas is the best way to know when to harvest .”
Environment
The growroom design and environment are very important to your success , and controlling it properly will be key to producing craft-quality bud . As soon as you see that your stigmas are at that 60-75 percent mark , you need to either lower your light intensity down 50 percent or turn half of them off . This mimics the sun being further from the plants at the end of summer because of the Earth ’ s axis and allows your buds to harden up properly , becoming much denser . You will also need to cut CO 2 off at this point . Your temperature should also be dropped as well down by about 2-4 ° F from your normal . We want to ease the temperature down gradually as with any transition in growing . CO 2 will need to be cut off at this point completely . All of this will help the plants ’ flowers harden up during ripening and develop the most aromas and THC possible .
Takeaways :
• Cut off CO 2 enrichment completely when initiating the flushing phase .
• Lower light intensity to 50 percent when initiating flush or turn half your lighting off if you can not lower intensity .
• Lower temperatures in the room by 2-4 ° F the first week of flush .
Advanced Ripening Techniques
Advanced ripening techniques will bring out the anthocyanins in your cannabis . These are the pigments or flavonoids that cause the purple color , changing the colors of your pistils from an orange to a deep red or pink . These techniques can massively increase your THC content or help sugar up the inside of a canopy that did not receive good light .
86 Maximum Yield