by Sirius Fourside
Buds usually start getting fat around weeks 4-6 of the flowering stage, but gain much of their total weight in the last few weeks before harvest.
Cannabis buds appear as little white puffs at first, then develop into the familiar nug shape over the course of a few months.
Buds start as white puffs. Blue Dream from Seed Supreme. 18 days after 12/12.
The puffs fatten into buds as they approach harvest day. Blue Dream left, Candy Games #38 right.
Those buds after harvest. Use GROWEASY at Seed Supreme for a free pack of Blue Dream seeds with your order.
Today, you’ll learn when cannabis buds gain most of their weight. Get a week-by-week bud flowering guide so you know what to expect.
The Bulking Timeline
Here’s a rough timeline of what to expect. Cannabis plants are living things, so these timelines can get pushed around by a week or so, but you can expect these changes in this order every time.
- Weeks 1-3: Flowering starts up. Producing buds takes a while, but the first white hairs typically appear 1-3 weeks after initiating 12/12. Do expect to see your plant gain height like a teenager bound for the NBA. The growth spurt is known as the flowering stretch and is much more pronounced in Sativa-leaning strains.
- Weeks 3-4: These weeks of flowering are spent creating the structure for the plant, not buds bulking up. That means the bud sites will look like puffs of thin and wispy white hairs (i.e. pistils or stigma) sticking out in all directions. That’s normal and a good thing. Your plant isn’t hitting the gym yet, but it’s ordered the equipment.
- Week 4-6: This is where buds start bulking, calyxes get fatter, and the smell starts changing from grassy to gassy.
- Most of the weight of the buds develops from here on.
- Weeks 6-8: Buds will still be bulking in weeks 6-8, but unless you’re growing an Auto or a FAST strain, they’re still not done.
- Week 8+: Now you’re really in the final stretch. These last few weeks before harvest are the weeks your buds gain a large portion of their weight. This stage of maturation requires the most patience so you don’t lose potential weight by harvesting too early.
- Seriously, don’t trust breeder timelines. If they say 8-week flowering time, it’s typically at least 9 weeks.
- Autos and certain FAST strains might only take 8 weeks.
- If your buds aren’t fattening by week 8, it might be another issue. Check out this page for more in-depth solutions: https://www.growweedeasy.com/why-buds-not-ready-harvest
The Cost of Harvesting Too Early
If you wait until the perfect time and harvest while the ‘harvest window’ is open, you would get the maximum amount your plant can yield in those conditions. Let’s call that maximum “100” to make it easy.
The earlier you harvest, the lower that number goes. Cutting your plants down before the harvest window is open can easily drive that number down to 90, or even 80. Waiting too long doesn’t affect yields, but it makes the weed more “couchlock-y”.
And it’s not just reduced yield; you get a potency drop-off at a similarly astounding rate. So you don’t just get less weed, but it’s not as strong. Additionally, the trichomes aren’t fully developed, so the effects can be speedy, over-stimulating, or give you headaches.
If your buds look like the one below, they’ve still got a long way to go.
How To Know If They Need Time
- Are there lots of white pistils still emerging all over the plant? They need time.
- Are the trichomes almost all clear with no ambers? They need time.
- Are there lots of cloudy trichomes? The harvest window is close to being open or possibly already open.
- Are there lots of amber trichomes? The harvest window is open! Some growers (like me) love this stuff, but for growers looking for maximum THC, lots of amber trichomes are a sign that you’re starting to dip below peak THC.
- Are your leaves yellowing? That’s natural for plants as they get late into flower. Don’t harvest your plants based on the amount of yellow leaves you see.
Check a spot near the top of the plant (on buds, not leaves) for ripeness. If you check the same spot each time (and take pictures), you’ll be able to see trichomes develop over time.
Check out our article on how to view trichomes: https://www.growweedeasy.com/pick-perfect-harvest-time-with-a-microscope
Help Your Plant Bulk Up!
- Keep the light strong – Arguably, this is the most important moment in its life for it to get intense light. Strong light makes denser buds and sticky, potent weed.
- Stay on your nutrient schedule as recommended by the supplier – Don’t increase or decrease nutrients at this stage beyond what your nutrient recipe entails.
- Keep the humidity low, around 45% RH – This keeps buds dense, makes them stickier, and greatly reduces the odds of bud rot or white powdery mildew.
- Have them standing tall – Some colas can get so big that they fall over from the weight of their own bud. String them back up with plant yoyos or sticks so they stay close to the light and continue to bulk up! When they’re slouched over, they can’t get as much light as the bulking slows down.
- Foxtails are not bulk – If you see foxtails forming on buds directly under the light, don’t count that as bulk. It’s a plant reaction to too much light.
- Note: There are some strains that grow foxtails even in perfect conditions, but those are less common.
Last Thoughts
Remember, harvesting at the right time gets you close to that ideal 100 rating. The earlier you harvest, the more that number decreases until you’re at 90 or even 80. Once you’re in the harvest window, any time is fine.
Here’s a trick: Look up your strain’s flowering time from the breeder (call that X). Then, make a note on your calendar that X weeks away from when your plants started flowering. You can call it the “no-harvest-before-today” date, and you don’t even have to worry about harvesting before that day arrives.
I hope that helps you assist your cannabis plants in making some bulky buds!
Looking for a guide to harvest? Our book gives you our effective home harvest system here.
Truly, A Manual for the Flowering Stage
by Nebula Haze (foreword by Sirius)
Cannabis plants can be fussy during the flowering stage. But when you’re prepared, instead, it’s just a nice time watching nature slowly make you some weed.
Fortunately, my partner at GrowWeedEasy.com Nebula Haze has put together an article so helpful, I think of it as a manual for the flowering stage. Even if you just started growing cannabis today and someone handed you a flowering plant, this article would get you most of the way there. No joke!
Need to know how the flowering stage works?
This is the answer:
Week-by-Week Timeline of the Cannabis Flowering Stage
Looking for a guide to harvest? Our book gives you our effective home harvest system here.
