|Parts of the mature female cannabis plant|
This is the part you've been waiting for: the main event. Bloomage. Buddage. Flower Power. During the FLOWERING STAGE, your plant will channel all its energy toward fattening up the bud sites & producing resin to trap pollen in an attempt to promote fertilization. But as long as no males are around, no seeds will develop & the buds will just continue to swell like the naughty girls they are. Fat, naughty little girls. 😈
Potassium (P) is the most important nutrient during flowering. While phosphorus increases the number of bud sites, potassium (K) boosts the actual weight of each bud as well as performing other vital functions. You'll want to pump up the potassium in Weeks 7 & 8 and maintain high levels until your pre-harvest flush. Potash, *banana tea & wood ash are natural potassium sources. Nitrogen should be in low supply during flowering but don't stop administering it altogether unless your plant looks dark green & you don't have any NPK fertilizer on hand. Just choose something with a higher P & K content if possible. Most bloom fertilizers are high in these two substances.
*(Banana tea nearly killed my plant as mentioned in the previous article. Proceed carefully).
Both temperature & humidity should drop during flower. Ideal temps are 65-80 F with 40-50% humidity. Be sure to keep your grow space free of standing water to avoid mold/mildew growth. Bud rot is a killer of crops that you don't want to deal with. If you're doing any defoliating or lollipopping, you might wanna do some in Week 7 or 8. I prefer to wait until Day 30 to remove fan leaves & Day 40 to take off unwanted bud sites (little "larfy" buds near the bottom that are unlikely to ever grow big) but you can make your own schedule. Leaves grow back pretty fast after defoliating so you might even be doing your second round by this point if you trimmed in Week 3 or 4. When defoliating, strategically remove large fan leaves that are blocking bud sites from getting light and anything near the bottom that's dead or dying. Leave all new growth near the top & healthy smaller leaves on each node in the middle. Check my example below:
|Botrytis, aka "Bud rot". Caused by wetness & cold temperatures.|
I gave my plant some light Epsom salt feedings (literally a few pieces of the salt dissolved in water) in Weeks 8 & 9 and a bit of pure Maple Syrup + Brown Sugar in Week 10 as a blackstrap molasses substitute. Not sure whether any of that had an effect, but I wanted to keep it simple after the banana tea catastrophe. The only feeds she really responded positively to were the Diluted Urine & Grass Clipping Tea. Everything else was either neutral or negative. Ahh well, live & learn. Next time I will be using store-bought nutes in flowering & suggest you do the same, as it's just easier & more precise.
If your plant doesn't already reek of pot by this point, it will soon. So have a plan for hiding it or keeping unwanted guests out of the grow room. An oscillating fan should be moving air through the grow space at nearly all times to help prevent mildew & pests and keep temperatures/humidity down. This is another advantage to growing only one or two plants in small containers--the stench is less potent than a large plant. My room only had the faintest skunk smell even during harvest & drying!
If you have any more CFLs or side lights, now would be a great time to start leaving them on for the whole light cycle with your other lights. I had my full 104 watts (84 watt CFL + 20 watt LEDs) blazing during flowering to boost my girl's potential. A flowering marijuana plant will soak up as much light as you can give her (to an extent), so don't be shy. Just make sure she's comfortable & not getting too hot.
So back to the question of whether your plant is ready to harvest. Here is the photo that helped me more than anything:
Notice the opaque, thick pistils (hairs) in the photo on the right vs. the shrunken reddish ones on the left. The "Not Ready" plant is also a darker green color compared to the light green one on the left. Its frost is more sparse compared to the almost velvety-looking texture of the mature plant on the "Ready" side. Your lady will look more like the one on the right from Weeks 7-8, while it will start to transition into the left look in Weeks 9-12 depending on the breeder & strain.* Be patient, as they really mean it when they say "Not Ready". Harvesting too early guarantees an unpleasant high, reduced terpenes & loss of yield.
*(Provided it's an autoflowering plant, that is. Most photoperiod plants take a lot longer to grow).
Of course there's the age-old trichome color thing which is still valid. But that's secondary to the overall look & context of the plant's ripeness. Once it appears ripe like the "Ready" plant above, you have about a 2-week window to harvest based on the effects you want. This is when you can really hone in on the exact feeling you want your pot to provide.
Cloudy white trichomes represent the peak of THC potency. Amber = CBN, or degraded THC. Some growers prefer a bit of amber in their mix for the relaxed/stoned sensation it provides. In addition to the color of the trichomes, the size & shape will also give clues to their readiness. A mature trich will often be tall & bent over like a candy cane under its own weight. Immature trichomes are clear & short and create unpleasant feelings like paranoia & headache, so aim for mostly cloudy or cloudy/amber trichs. And make sure to look at the actual bud calyx rather than the sugar leaves when viewing the trichomes, as those are what count. You will need a microscope or jeweler's loupe (magnifying glass) to see the tiny trichomes in detail.
Here's an example of what the various stages look like under magnification:
In our next installment we'll delve into the final days of your plant's life: the flush, harvest & trim. These are some of the most hands-on parts of the whole grow & are really fulfilling. Be sure to tune in. We'll also explore some (unproven but popular) last-minute stress techniques growers use to boost trichome production before harvest. You can decide for yourself if they sound like "Science, Bro" or "Bro Science". 😜