Nebula’s Auto-Flowering Grow Journal (Topping vs Natural)

Last updated Nov 03, 2023

by Nebula Haze

Note: This grow journal is over. Click here to see the final weights and lab results! 

It’s time to start my next cannabis grow. These plants should be ready to harvest around Christmas or New Years. It’s going to be exciting!

Here are the autoflowering cannabis plants at 5 weeks from germination (the upper tent was topped in week 3). Keep scrolling for the full grow journal including tons of pictures from germination to this point and beyond. Which tent will end up being the winner?

This grow features multiple auto-flowering strains in two tents. I’ll let the plants in one tent grow naturally without any plant training. Just let them grow and see what they do. The other tent will feature plants that I train as normal (cut off the top above the 5th set of leaves and spread branches out as the plant grow, tying down any tall branches).

Example of untrained (naturally grown) auto-flowering plants from a different grow

Example of auto-flowering (Ruderalis) cannabis plants just before harvest!

Example of an auto-flowering cannabis plant that I trained according to the technique described below

Sweet Seeds Black Jack Auto - this plant grew thick and chunky colas

My Hypothesis:

Plant training increases yields for auto-flowering cannabis strains (when done as outlined here).

Proposed Experiment:

Two identical grow tents. There will be 4 autoflowering strains, with one plant of each strain in each tent. One tent gets training, the other doesn’t.

Here is the plant training I will do to the auto-flowering plants in one tent. The other tent will be left alone to grow naturally.

  1. Wait until the seedling has grown 6 nodes (sets of “real” serrated leaves), hopefully around week 3.
    1. If the plant grows any pistils/hairs (a sign it’s about to start flowering), then top it immediately. You never want to top an autoflowering strain after it’s started making buds or you greatly increase the chance of stunting.
  2. Cut off the tip of the plant right above the 5th node, through the main stem. In other words, “top” the plant above the 5th set of leaves.
  3. Bend over the tallest branches as they grow and tie them down and away from the center of the plant using plant twistie tie.
    1. When possible, tuck away leaves that are hiding growth tips from the light, to ensure all lower and side branches get enough light to develop
    2. If any branches start getting too close to the light or seem to be growing taller than the others, bend that stem over and tie it in place to help keep the canopy an even height
  4. Main goal: Try to spread the plants out to fill up space under the light

This grow journal features the ES300 LED grow light by the Green Sunshine Company, which was a great light but has unfortunately been discontinued. However, the Mars Hydro TSL2000 has been getting similar results, uses the same amount of electricity, is used the same, and as a bonus costs significantly less. The only downside is the casing is not as professional or nice as the ES300s were.

Note: This experiment will feature plants grown from seed instead of clones because all auto-flowering plants are started from seed. This means this will not be as accurate as my typical side-by-side grows which feature clones. However, this is still a fun experiment to get a visual idea of how plant training affects auto-flowering plants. I’ll start several extra seeds so I can do my best to match strains.

 

Setup & Supplies (one set for each tent)

Grow Light

  • ES300 LED grow light (discontinued) – Recommended replacement is the Mars Hydro TSL2000, which is a 300W LED grow light that has been producing similar results and actually costs less. The only thing that’s not perfect about the Mars Hydro TSL2000 is it has a really cheap aluminum casing. But that has no effect on its actual performance.

Grow Space (tent with exhaust fan)

  • Grow tent – 2’x4’x6′ grow tent
  • 6″ exhaust fan – AC Infinity Cloudline T6 – Exhaust fans are used to remove heat from the grow space and bring in fresh air for the plants. Any 300W LED makes some heat and it’s good to have an exhaust fan so plants get plenty of CO2 in the air. You also need an exhaust fan if you want to stop smells because a carbon filter doesn’t work without a strong exhaust fan. The AC Infinity is quiet but expensive; the Vivosun 6″ 390 CFM exhaust fan is a cheaper alternative that’s both stronger and louder). Learn how to vent heat with an exhaust fan.
  • (optional) 6″ carbon filter connected to the exhaust fan with 6″ ducting – Carbon filters are used to stop smells from leaving the grow space. Learn about carbon filters.

Here’s a picture of my last grow in this setup. I’m using the same tent, LED panel, grow medium, pots, nutrients, etc. (the carbon filter is above the light.)

Plant Containers

  • 3-gallon fabric pots
  • 1020 Heavy Duty plant trays to catch runoff water (plants saucers are a cheaper alternative but I like that putting the trays on a slight incline causes all runoff water to pool forwards for easy collection with a wet vacuum)

Grow Medium

Nutrients

  • Vegetative Stage – Dyna-Gro Foliage Pro
    • 1/4 tsp per gallon for seedlings
    • 1 tsp/gallon after that
    • 6.1-6.3 pH
  • Flowering Stage – Dyna-Grow Bloom
    • 1 1/4 tsp per gallon for the first 4 weeks after plants start flowering
    • 1 tsp/gallon after that until end of grow
    • 6.1-6.4 pH
    • Give plain water for 1-2 waterings before harvest

Note: Dyna-Grow Bloom will greatly lower the pH of your water. Make sure to use PH Up to keep it in the proper range if necessary. I kept my pH between 6-6.5 throughout the grow (I’ve found this range seems to get the best results in coco under LED grow lights with Dyna-Gro).

Strains

 

Grow Journal

Week 0 – October 15, 2021

Seedlings… sprouting! With an expected grow time of about 10 weeks from seed to harvest, these auto-flowering plants should be ready to harvest before Christmas.

 

Week 1 – October 22, 2021

Seeds have sprouted into seedlings. I kept them in Rapid Rooters until every seedling had opened their leaves, then put them in paper cups. I’ve kept the 3 best seedlings from each strain to give them a few more days to see how they develop before putting them in their final 5-gallon pots.

I aim to pick the most similar two seedlings from each strain, and put one plant of each strain in each tent.

Since these cannabis plants are growing from seed instead of clones (all auto-flowering plants always start from seed), they’re like siblings as opposed to twins. That means the experiment is not as precise as it would be for clones. However, I am matching the seedlings as best as possible for the purposes of the experiment and I think it’s going to be fun and informative to see how the autoflowering plants react to plant training vs growing naturally. Luckily, they all seem to be developing at about the same pace so far.

Next week they should be in 5-gallon pots with one plant of each strain in each tent. Then the real fun begins!

 

Week 2 – October 29, 2021 – Transplant day!

Put seedlings into 5-gallon pots today! I let them get a little underwatered this week and they’re growing a little slowly. This worries me a bit since they’re auto-flowering strains and we’re on a tight schedule, but I think they’ll be much happier once they’re put into their real homes. In the future with auto-flowering strains, I’ll put all seedlings directly into their final plant container. Even if I make a few extras, I’ll just find new homes for any extra plants. I don’t mind wasting a few extra pots and coco if it helps plants grow faster.

I moved one seedling to a pot before I remembered to take a picture of them. But here’s most of them before being transferred!

And here are all the plants right after being transferred to their new homes. I kept the extras in an identical tent in the same position as these so that I have an extra option for each strain. My goal is to get the plants as closely matched as humanly possible before I start the experiment.

Now we have about a week to see how they do before it’s time to top them. Fingers crossed that they’ll each have at least 6 sets of leaves by next Friday 🤞 If not, I’ll just top them above their highest set of leaves and they’ll be fine.

 

Week 3 – November 5, 2021 – Topping day (for one tent)

Plants are 3 weeks old! With auto-flowering plants, this is the time to “top” the plants (cut off the tops). If I wait any longer, some plants may start flowering. If you cut off the top of a plant after it starts flowering, you increase the chance of possibly stunting it. By “stunting” I mean that the plant will stop growing taller and stay essentially the same size. If you’re looking to keep short plants, that’s fine. But for the purposes of this experiment, I want to top the plants before they start flowering to keep everything as equal as possible.

Here are all the plants in one picture.

Nutrient schedule: I’ve been giving them 1 tsp/gallon of Dyna-Gro Foliage Pro. This nutrient is more acidic than most nutrient systems, which I like because it naturally brings my high-pH tap water to 6.3 pH. Perfect for growing in coco. Talk about easy when you only have to add 1 tsp/gallon and that’s it. I’ve been giving each plant about 2 cups of nutrient water a day. Just enough to keep them moist, but not overloading them yet since they are still small with small root systems. I’ll probably start raising the amount of water this week.

Grow light: I have the 300W LED grow lights 24″ away from the tops of plants. I will let the plants grow up to the light and then raise it to keep it about 18″ away for the rest of the grow.

I’m pretty pleased how closely matched the plants are at this point since today marks the day where the tents will diverge. I went through a lot of seedlings to ensure I had really good matches for each strain and I think my efforts paid off.

Here are the tents right next to each other before today’s session.

Since they were on the smaller side last week, I was a little worried they might not grow enough sets of leaves in time (today is 3 weeks from when they were put in Rapid Rooters) since the goal is to top auto-flowering plants before they start flowering and strains typically start showing pistils week 3 or 4.

I was so excited to see every single plant had grown at least 6 sets of leaves, so I could top above the 5th as planned. None of the plants have started flowering yet, so now is the perfect time to top them. Whew!

Tent 1 – Left alone completely

Untrained (these plants will be left alone until harvest except to get water). This is the “control group”. You can identify this tent because the cord from the light is in the middle behind the plants, while it’s on the right in the other tent.

Tent 2 – Topped and leaves tucked

I cut off the top of these plants today and tucked some of their top leaves to help expose the lower stems to light. Their branches will also be bent and tied down as they grow to help get as many branches exposed to the light as possible.

It’s captivating to think that the primary difference between the two tents is that I cut this much off the top of each plant. I’m so excited to see what the difference ends up being at harvest time.

Here they are after being topped. I stuck a green stake in the front of each plant that says “topped” to make it easier to identify the trained plants. Once they start growing I think it will be a lot more obvious which tent is which.

Oh boy! Will the tents look different by next week? Will the plants start flowering before the next update? I can’t wait to see!

Bonus Set of Plants

I had extra plants for each strain. I didn’t have the heart to toss them so I set 4 of them up in their own tent under an HLG 100 R-spec LED grow light in a small grow tent (2’x2’x4′ or 0.6m x 0.6m x 1.2m). I love this little LED for small spaces. Let’s see what these plants can accomplish with just 25W of light each to themselves. I think it’ll be fun to see how these ones develop in comparison to their sisters in the bigger tents that have more space and light.

Here’s some weirdness for you from the little tent. The Zweet Grape plant is a mutant. I’ve seen lots of mutants grow a lot of ways, but this one is unusual in that I’ve never seen a new stem grow off a petiole before (the “petiole” is the stem that connects a leaf to the plant).

Learn about cannabis mutants

I noticed something was weird with this one in week 2. Luckily I kept extra plants of each strain so I didn’t have to use this as part of the experiment. It looked like the plant had split into two leaves, like it had topped itself. Then I noticed a new stem growing directly out of one of the leaf petioles (a “petiole” is the stem that connects a leaf to the plant).

This is a week later. The new stem started growing out and appears to be growing normally.

However, the growing branch in the lower right of the above picture (the branch right under the stem split) is “whirled” (spinning) with multiple leaves and branches emerging from the same spot.

I made a little moving gif if you want to look closer. The numbers show the 4 leaves. The arrows point to 5 new branches/growing tips emerging from the same spot (2 major ones that have grown out and 3 undeveloped ones at the base). If you look at the two bigger branches (with the two bigger arrows) you can see they look like their ends are weird, too. I can’t wait to see how they grow out.

Click the moving gif to see a bigger version (this is the end of the mutant whirled branch, with multiple stems and leaves emerging from the same spot)

I love a good mutant. Typically mutant cannabis plants don’t grow as fast or yield as much as regular plants, but sometimes they shrug it off and catch up to their siblings. In any case, they’re always fun and interesting to watch grow up 🙂

 

Week 4 – November 12, 2021

Plants are growing fast! They’ve really picked up in speed over the last few days. The topped plants (tent on left) seem like they possibly were a tiny bit stunted from their topping a week ago, but I’m not certain. It’s possible that it seems that way because they’re growing multiple branches, which means the plants energy is split more ways. The untrained plants only have one main stem and are getting tall quickly.

Topped tent on left. Untouched tent on right.

Here’s view with the topped tent on top (plants were topped and branches are getting bent down to maintain a flat canopy), and the untouched tent on bottom (these plants have been getting water and that’s it; no training whatsoever).

The topped plants are certainly wider, while the untouched plants are taller. It’s hard to know what will happen next.

A leaf from the Sour Diesel plant I removed today from the topped tent (it was blocking a bud site)

This week didn’t produce a whole lot of changes that you can see in pictures, but their underlying structure is very different. I’m curious to see how they progress now that the plants in the topped tent have so many main branches compared to the untapped plants. Will they tend to stay short overall, or will they catch up in height?

 

Week 5 – November 19, 2021

Wow, what a difference a week makes. Major contrasts between the tent are now easy to see.

Some untouched plants are up almost double the height of the plants that were topped. They also just seem bigger overall. It’s obvious that the topped plants were stunted in some way (whether that’s good or bad in the end, we will see).

The other major difference is the plants that were topped seem to be further along into the flowering stage. It’s like the shock of being topped put flowering into overdrive. While all the topped plants have plenty of pistils/white hairs, the untopped plants barely have a few here and there. I thought this was interesting because people generally tell you there’s nothing you can do to change the flowering schedule of an auto-flowering strain. And although these are grown from seeds instead of clones, the fact that it seems to be the case across the board for 4 different strains lends some evidence that topping an auto-flowering plant may possibly get it to start flowering sooner than it otherwise would.

I used lines to indicate the top of the tallest plant in each tent. The topped plants (left) are relatively short while the untouched plants (right) are still getting taller every day.

Side by side of auto-flowering plants. Left tent was topped, right tent was left untouched. The untouched plants have gotten significantly bigger

Topped plants

  • Flat canopy – I’ve been bending and tying down any tall branches, so all the plants are about the same height
  • Shorter – In addition to being tied down, they didn’t gain much size after being topped and seem to have mostly stopped getting bigger. All plants are between 14-16″ (35-41 cm) tall.
  • Faster flowering – The buds on the topped plants have developed significantly more than the buds in the other tent. It’s like the shock of being topped made them start flowering earlier/faster.

Untouched plants

  • Uneven canopy – Some plants are getting much taller than others. Luckily as soon as I noticed which strains were getting the tallest, I moved them to the outer edges in both tents because I knew that would reduce light intensity from the LEDs (the light is most intense directly under the middle of the LED panel). In general, it’s always a good idea to keep your tallest plants on the outer edges.
  • Taller – All plants are taller than all plants from the other tent (and still getting taller every day). From left to right the plants are: 26″ (66 cm), 18″ (45 cm), 19″ (48 cm), 24″ (61 cm). Quite a bit of variation!
  • Slower flowering – Although these plants have started flowering, they just have a few pistils/hairs with no significant buds yet. It seems like these plants have overall been slower to start flowering.

Could topping an auto-flowering plant cause it to start making buds sooner? So far it looks like that may be the case (at least for these 4 strains).

The topped plants are well into the flowering stage, showing bunches of white pistils/hairs

In week 5 from germination, these autoflowering plants are well into the flowering stage with lots of white hairs

While the plants that were not topped have barely started flowering

We’ll see if the differences are starker next week, or if the untopped plants start catching up.

Here’s a quick look at each tent at week 5. I tried to match the angle and dimensions between the two pictures to give the most accurate comparison. Top tent plants were topped and branches tied down. Bottom tent plants were untouched (only water).

I’m not sure if this moving gif might make it easier to compare. I tried to match the pot size and position as best I could.

Will the untouched plants keep getting taller or will they finally slow down and start focusing on making buds? I’m not sure but I’m excited to see them every day and can’t wait to report back next week 🙂

 

Week 6 – November 26, 2021

This week plant growth was absolutely explosive. I started giving the plants flowering nutrients and they seemed to shoot up in both tents, but especially in the untrained tent. Normally I would supercrop/bend the main stems of the untrained tent to make the tallest plants shorter, but for the purposes of this experiment, I’m going to leave them alone and see what happens. Luckily I set up the tallest plants to be on the outside edges, which will help prevent them from getting light stress if I run out of room to move the grow light up.

The autoflowering plants in the untrained tent are getting BIG, yet only just seem to be getting into full swing of flowering

The untrained tent is a little out of control. Stay tuned for next week to see how this goes! I may have to intervene to keep the plants from growing into the light if they don’t stop soon but I’ll try to hold off as long as humanly possible. These plants are drinking more than twice as much as the plants in the other tent, and their buds are only just starting to form. Overall they seem much bigger but are much slower in bud development compared to the other tent.

Untrained tent at week 6. The two outer plants are over 3 feet tall! (about 1 meter) if you count their main bud.

4 autoflowering plants in week 6. Not topped or trained. They've just received nutrient water and that's it.

Notice where the sticker is located at the back of each tent. I purposely put the stickers at the same height in both tents to help monitor the difference in size between the plants.

The topped and trained tent had some plants that were getting a bit too tall for my liking so I supercropped them to make them shorter. As a bonus, supercropping an autoflowering plant tends to “stunt” it and cause stems to stop growing taller, which is exactly what I want at this point.

Topped tent at week 6. Notice how the two right plants are starting to get taller than the rest. An easy fix with plant training.

Autoflowering plants week 6. They were topped in week 3 and just about to get supercropped

After a supercropping session, the canopy is more even with fewer stretchy branches

Two of these week 6 autoflowering cannabis plants were just supercropped

The plants were all on a 20/4 light schedule but I switched them to an 18/6 light schedule today. Although autoflowering plants grow bigger buds if they get more hours of light each day, I hope a longer night may help the plants in the untrained tent flower faster. Longer nights cause cannabis plants to “think” winter is coming and even autoflowering strains tend to develop faster under 18/6 vs a longer day.

Well I know I can’t wait to see what happens next! I have a feeling that things are going to be crazy next week.

 

Week 7 – December 3, 2021

Did any of the plants go crazy this week? Yes. Yes, they did. The untrained tent now contains the biggest indoor plant I’ve ever grown.

Untrained tent. Wow!

The untrained, untopped autofloewring tent is getting out of control at week 7. Luckily they all seem to have stopped getting taller!

In natural light

Autoflowering plants week 7 from germination. Untrained (just water only) and getting out of control!

The Sour Diesel Auto plant on the far right is just under 5 feet (1.5m) tall. It’s absolutely monstrous. It finally stopped growing taller.

It is soooooo hard not to prune these plants. I want to cut off half of those branches. But I’m holding off for the sake of the experiment.

The plants are so big that the bottom leaves are dying and falling off. Even if there’s no nutrient deficiency, cannabis plants abandon leaves that spend too much time in the shade.

If leaves are in the shade they will turn yellow, die, and fall off. This isn't a nutrient deficiency. The plant is just abandoning leaves that aren't helpful anymore.

Here’s a view from the top. From what I can see so far, it looks like the Sweet Grapes Auto plant on the left is going to yield quite a bit

Autoflowering marijuana plants in week 7 from germination - overgrown!

Here is the grow tent with the topped and trained plants. Much more orderly, and the buds are further along, but plants are less than half the size.

The Sweet Grapes Auto plant on the left in this tent is going to be a huge producer in this tent, too. It’s buds are twice the size of the others.

Which tent will yield more? I am not sure yet. The untrained plants are humongous but have only a few buds per plant compared to about a dozen on each trained plant. The real deciding factor will be how far the buds fatten down into the plants. The longer the buds end up being, the more likely the big plants will yield more overall.

Nutrients: The plants have stopped growing vegetatively and their leaves look a little too dark so I’m reducing their nutrients starting this week from 1 1/4 tsp/gallon of Dyna-Gro Bloom to 1 tsp/gallon. I’m also going to lower the light in the trained tent. I had it 24″ (60 cm) away while they were getting taller. They’ve stopped growing now, so I’m going to lower it to 18″ (45 cm) away until harvest to help buds fatten as much as possible. In the untrained tent, some plants are further than 24″ away and others are less than 10″ (25 cm) away, so I’m just going to leave the light where it is.

 

Week 8 – December 10, 2021

We are hitting the home stretch! The buds all got bigger this week, but other than that I didn’t notice many changes.

Untrained tent – it’s a jungle in there. Notice how little light is getting past the top canopy

Week 8 autoflowering plants - grown naturally (not trained or topped).

Here’s a closer look in natural light. Buds are starting to gain in size!

Week 8 autoflowering plants - given water only, grown under an ES300 LED grow light

I’ve never allowed any plant to grow this tall and wild before, and it’s been interesting to see how the plant is dealing with the leaves at the bottom. These leaves haven’t received any light in weeks now. The plants are actually “abandoning” leaves and any bud sites at the bottom. Yet the rest of the plants are green and healthy.

Bottom leaves have not gotten any light in weeks. As a result they're turning yellow and falling off.

The LED is currently at the top of the tent and can’t be moved up any further. The Sour Diesel Auto plant on the far right has essentially grown into the panel. So far it looks surprisingly green and healthy, but I suspect the top leaves will start turning yellow and dying early from the intense light levels, especially since I know that cannabis plants get less and less resistant to plant problems throughout the flowering stage.

Pretty impressed with the 300W LED grow light. It’s designed with a gap in the middle that helps accommodate plants that grow too close. Despite being only inches away, the top of the plant still has green leaves.  That main bud is going to get fat!

Sour Diesel Auto is growing almost into the LED grow light, but still looks mostly green and healthy without light burn

The Zweet Grape Auto definitely has the biggest buds so far (which isn’t too surprising since it started flowering the earliest)

Here is a bud on the Lemon Auto

Lemon Auto week 8 from germination

Critical Purple Auto

Critical Purple Auto - week 8 from germination

Sour Diesel Auto

Sour Diesel Auto week 8 from germination (in the untopped tent)

Now on to our trained tent. Talk about a totally different garden.

Topped & trained autoflowering tent

Week 8 autoflowering plants under ES300 LED grow light

Here they are in natural light

Autoflowering cannabis plants in week 8 - topped and trained

The individual buds in this tent are smaller than the main bud on each of the untrained plants. However, there are way more of them in this tent. I can also see that the buds are a little further along because some of the white hairs have darkened hairs while the other tent has almost pure white buds. Again, that makes sense since these ones all started flowering sooner. It looks like they’ll probably be ready to harvest a little earlier than the other tent.

The Zweet Grape Auto buds are sparkly

Zweet Grape Auto week 8 autoflowering buds

Lemon Auto

Lemon Auto - autoflowering plant week 8

Critical Purple Auto

Critical Purple autoflowering buds - week 8

Sour Diesel Auto

Sour Diesel auto - week 8 from germination

The buds will continue to fatten and mature over the next few weeks and I expect these will be ready to harvest around the New Year. Stay tuned!

Week 9 – December 17, 2021

Not much change this week. Just chugging along as buds mature and fatten.

Untrained tent

Week 9 - autoflowering plants - untrained

Week 9 - autoflowering plants - untrained plants in natural light

Still loving the 300W LED grow light! The top of the Sour Diesel plant is somehow able to handle the brightness even this close

Trained tent

 

Week 11 – December 31, 2021

I missed last week’s update over the holidays but I got one for you this week. Don’t worry, nothing really happened except the buds kept maturing. It looks like harvest time is coming soon.

Untrained tent

That Sour Diesel plant all the way on the right would have a beautiful plant structure if you could ignore the enormous (but mostly budless) body underneath. It’s been really interesting to see how the plants all grow when they’re allowed to run wild and free.

Top of Sour Diesel plant on the right. I’m noticing some yellowing but overall it seems to be handling this light intensity surprisingly well and buds are getting FAT. Just like a photoperiod Sour Diesel plant.

Here is the tent in natural light. What beasts!

Each tent is the same size. Check out the exit vent on the upper left of each tent for reference on how much shorter the other plants are in person.

Now the topped and trained tent.

Here they are in natural light

I’m actually kind of curious which tent is going to yield more. The trained plants are little bud balls (much higher bud-to-plant-size ratio), but the two outer plants in the untrained tent have so many loooong buds I think their sheer size may give their tent the win for yields.

My other big question is how their THC and terpene percentages will compare after getting the buds tested in the lab. The trained tent with the smaller plants seems like it smells much stronger and buds may be sparklier, but I’ve found over the years that it’s a crapshoot to guess THC or terpenes (smell) before the results come back.

It would be interesting if the tents ended up having significantly different lab results because that would indicate topping and training plants in the vegetative stage has an effect on bud quality in the flowering stage. I’ve heard growers theorize about the effects of early stress on bud potency, but how crazy would it be to get lab results with objective evidence?

Getting close. I may have harvest pictures for you next week, but if not it will definitely be the following week. I’m also germinating seeds today in preparation for my upcoming side-by-side grow that tests the effects of flowering stage defoliation on plant yields and growth. Stay tuned 🙂

 

Week 13 – January 15, 2022

New Year, new harvest! Today was the final harvest day. I felt certain that the “untrained” tent with the bigger plants was going to have the biggest yields, but when I started harvesting I realized that the “trained” tent with the smaller plants may actually pull ahead. Although the bigger plants had long buds, the shorter plants were total bud balls. Every plant had multiple fat buds while the untrained plants had only a few each. I can’t wait to do the final weigh-in in about 10 days after they’re done drying.

Untrained tent before harvest – Final Yield 10.6 oz

In natural light

Drying in tent after harvest – this took a surprisingly long time because there were so many branches

Trained tent before harvest – Final Yield 10.8 oz

In natural light – look at all that purple that appeared in the last week!

Harvested and drying in tent. Harvest went MUCH faster with this tent. The plants were much shorter than in the other tent, but once I cut off all the branches it was pretty amazing just how many fat buds each plant was hiding. I think this tent may end up winning for yields

I have them all drying in their tents with the fan on the lowest setting. I also set the Air Conditioner to keep the dry room at 60°F (15.5°C) and the humidity in the tents is almost exactly 60% RH. I’ve had the best luck air-drying in 60°F/60% RH (never mold, never harshness) so I’m pleased with the current drying conditions. The buds should take about 10 days to dry at this rate. Then the weigh-in and finally the lab test results!

 

Final Weights & Lab Results

Here’s a quick overview. Keep reading the full results!

Get the lab results on THC percentage and certain tests on autoflowering cannabis plants (trained vs untrained)

These are the final weights with the strains ordered from left to right in each tent.

Untrained tent

Total: 10.6 oz (299.4g)

 

Trained tent

Total: 10.8 oz (307.73g)

Here are the papers I used to collect the data.

Final thoughts

This grow journal featured auto-flowering plants grown in identical conditions in identical tents. In the “trained” tent I topped all the plants and trained them to stay short, while the plants in the “untrained” tent were left to grow wild. I didn’t do anything to those plants except water them.

The idea was to find out exactly how this affects the yields and bud quality. I did think the trained tent was going to have significantly bigger yields but the untrained tent grew so wild that the big plant on the right yielded a lot even though the other three did not. As a result, the yields were almost the same.

I have to admit I’m super excited about seeing the lab results. I’ve heard growers over the years say that topping and training plants may cause them to grow higher levels of THC and smells, but it’s pretty shocking to see it play out that way in the lab results.

Winner: Trained Tent

  • Slightly bigger yields
  • Higher THC levels
  • More terpenes (stronger smell)
  • Buds are significantly denser
  • Higher overall bag appeal

There isn’t a single measurable factor where the untrained tent won. Now it’s important to remember that these are autoflowering plants, which means they were grown from seeds instead of clones. Instead of twins, the plants were siblings. That means that the changes between the tents could be partly a matter of natural variation. I would have to repeat the test a few more times in order to feel confident about the results as far as THC, yields, and terpenes.

That being said, I feel the results are pretty clear in my mind. Unless I re-run the experiment, I don’t plan to ever let auto-flowering plants grow wild indoors again 🙂

 


 

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