by Nebula Haze
Finished! Go to the end.
Extra mom plant put in a 2’x2’x4′ grow tent under Spider Farmer SF-1000 LED
I had a few extra plants (they were moms for clones for my defoliation side-by-side grow experiment). I also have a Spider Farmer SF-1000 LED grow light (4000k) and a 2’x2’x4′ mini grow tent.
This Spider Farmer SF-1000 LED grow light only uses 100W of electricity and does not put off a lot of heat
A 2’x2’x4′ mini grow tent is a great size to grow small cannabis plants with a 100W LED. I’m using a tent by CoolGrows.
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
April 9 – Trained plant to be flat
Here’s the mom Runtz plant. It has produced many clones and is now ready to make buds of its own
Before I initiate the flowering stage, I’m going to use twistie ties and bending to force the plant into a flatter wider shape. Because it was a mother plant as opposed to trained to be flat, it has a bunch of weird branches sticking in odd directions. Although this isn’t necessary, keeping all the branches in a wide flat “table” shape helps increase yields, especially with small lights, by ensuring that there are many main buds instead of just one, and all buds are an equal distance from the LEDs.
I used plant twist tie and bending to force the plant to be more flat to increase yields in the flowering stage
Here’s the plant in the tent. It’s flat wide shape almost completely fills the space under the grow light. Perfect!
The leaves should all be turned back up tomorrow and then I’ll initiate the flowering stage. Because this is such a small grow space, I want to initiate flowering as soon as possible so the plant doesn’t accidentally overgrown the space. Remember, during the first few weeks after 12/12, the plant will about double in size (known as the flowering stretch) or possibly even more.
April 10 – Initiated 12/12
Today I initiated 12/12 (put the grow lights on a timer so lights are on 12 hours a day, and off 12 hours a day) to get the plant to start flowering (making buds). This is what the plant looked like.
All the leaves have turned back up by the next day.
From the top you can see that we have pretty decent coverage in the tent for just one small plant that had to be retrofitted to the space.
April 15 – Already starting to see flowers
Just 5 days later, I can see the plant starting to make a few pistils.
Mom plants tend to start flowering quickly because they are older and more mature internally than a similarly sized plant grown from seed. Essentially, they’re “ready and raring to go!”
Plant is looking good
Buds are beginning to develop
April 22 – Buds continuing to develop
Runtz plant has stretched a bit taller and buds are starting to fatten up
Closeup of flowers
May 6 – Buds are developing nicely
This plant has been receiving nutrient water and otherwise I haven’t really touched it. I gave vegetative nutrients for 2 weeks after initiating 12/12 and in week 3 I switched to flowering nutrients. The extra nitrogen and potassium in the vegetative nutrients help cannabis plants develop well during the flowering stretch with lots of bud sites, but from now on until harvest the plant needs much lower levels of nitrogen, which is why it’s time to switch to flowering nutrients.
Marijuana plants often need lower levels of nutrients when they’re growing under a small light like this 100W Spider Farmer LED. Less photosynthesis requires less nutrients. The leaves on this plant look a little dark in natural light so I’m now giving nutrients at 1/3 strength. I’ve been giving enough nutrients for one gallon, but mixing it in 3 gallons of water so the plants are receiving 1/3 strength compared to what’s on the official schedule. I’m growing a clone of this plant in another tent under a bigger 300W LED grow light and that plant can handle much higher levels of nutrients.
Here’s a picture of the plant with a flash so it’s easy to see the bud structure. It’s a bit stretchy with some long stems in places, but overall it’s covered in buds that are developing great under such a small 100W LED grow light
Closeup of some buds (these are about 4 weeks from initiating 12/12)
May 21 – Buds starting to look mature
Buds have fattened quite a bit since the last post. I haven’t done anything but give nutrient water every few days and let the plant develop. This plant is now about 6 weeks from when I first initiated 12/12. I expect it to be ready to harvest by the end of the month
Closeup of a bud – sparkly!
Harvest Plus Experiment: How does a 3-day dark period before harvest affect THC percentages?
I decided to do an experiment with these buds to test how THC changes during the last few weeks before harvest, as well as test whether a 3-day dark period significantly changes the THC percentage of buds.
So today I’m taking a sample of buds and drying them. I’ll take another sample in 1-2 weeks when these buds are ready to harvest, put the plant in a 3-day dark period, and take one more sample. Then I’ll get it all tested in that lab!
Runtz plant right before harvest
Let’s see how these buds test against each other in the lab.
- Before 3-day dark period: 16.9% THC
- After 3-day dark period: 17.6% THC
Wow! This was a spur-of-the-moment test without any controls, so take this with a grain of salt. I must run more side-by-side experiments to see if this is a fluke. It’s hard for me to believe a dark period could increase the THC this much on a consistent basis. I wonder if there is some other factor. Perhaps it was natural variation between the buds. It’s also possible that harvesting half the plant increased THC in the remaining buds through stress, and it had nothing to do with the darkness. Or some unknown factor.
A followup experiment is definitely coming. This first one was last minute and not well planned. There were no control plants. But the next experiment will involve clones and I’ll harvest plants separately before and after the dark period to reduce the total number of variables. Maybe I’ll think up some other similar tests. Such an exciting time to be a grower!
Check out more side-by-side cannabis growing experiments.
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