How To Make A Sativa Short

Yes I noticed that in some of the older books I have, I also noticed that max THC content has gone from 5% to 20+% since the 80's, according to what I'm reading.

That has nothing to do with growing under MH/HPS. That's genetic.

oh, I actually just started a thread on that topic in the newb central to find out why that is, I figured genetics is the answer, but that really is shocking. Im really glad I learned about the option for using MH during start of vegg to prevent stretch, sounds like a really usefull tool in what im trying to do, Too bad they dont make 600w MH or at least I havent heard of it, Im not gunna have enough light unless I buy another 400watt MH

Yeah, that's always been the biggest deterrent for me. 600w is just so perfect isn't it?

Thedillestpickle Im quite new to the MJ growing game but Im also in the opposite boat, I want a little more height out of my plants. So if it helps I was running high 60's temps and high 60's humidity while direct fanning. Mine seem to wanna be around 15 inches and thats it, although they are filling out more after a temp increase. Ive grown lots of food but not much MJ but in in my experience let your natural gut feeling lead the way and results will show, input is always great from other people but sometimes you gotta go with what YOU think will be the answer......best way to learn! Cheers man!!

Umm...there are lots of 600watt metal halide bulbs. Or did I miss some sarcastic joke somewhere?

no sarcasm and Ill take a look now that you said that, I just remember seeing MH in small sizes and then 400 and then 1000... HPS made a recent innovation with the 600 and I dont think MH has done that yet, but I could be wrong(and hope I am)

ok just did a quick google and yes they are around... my jorge cervantes book fails me again...

Thanks for pointing that out Karr I probablyl wouldnt have looked into that since I was already convinced they werent around.

No worries. It's rumored that they will be making a pubicly available 600w CMH sometime too, so that's cool, although i have a digi ballast so no go.


On topic, really not a lot you can do without touching the plant but, frankly, I'm not sure why you wouldn't want to touch the plant. A simple bending of the top towards the bottom can increase yield quite a lot situationally.

I actually plan on topping once above the second node, and that should give me a shorter plant as is, I guess the reason is I dont want to trigger the plant to bush too much as Its going to be 90% sativa strain(kali mist) and this strain has light airy buds usually and i dont want to to have popcorn buds growing on a shrub. I also dont want to have lolipop or buds that reach up to the bulbs. Id like to have some impressive colas on my plants. Ive been looking at hobbes' thread in the strain reviews on his grows with Kali mist. Its extremely impressive, I wish he was around still so I could get some advice on nutes from him as he seemed to have his plants growing really nice, he was getting 2 gpw with his setup(with a light over) Im not looking for GPW, more "grams per plant" I have a room 6x4x6 and I am thinking of running 2 600's and a 400 if I can manage the temps with cool-tubes. its concrete on two walls and 10-13 degrees celcius through the winter down in the basement so I think I might be able to pull it off. right now Im burning almost that just on the baseboards to keep it warm so I might as well be doing it with light. With what hobbes has got going on I might just do the LST like you see with his, except given that I have more room and only 5 plants(assuming 50% turn out female) than I can probably use something a bit wider than his tomato cage setup, so thatll let me vegg for longer and have them wrap around a larger diameter, heres his thread so youll know what I mean https://www.rollitup.org/seed-strain-reviews/244207-kali-mist-serious-seeds-strain.html . until now I had been thinking of doing a setup like this https://www.icmag.com/ic/showthread.php?t=221265&page=10 Now Im not sure what I should do, I do have a 6 foot ceiling and it may be possible to mount my lights even higher if I can get a hood with a narrow reflector as that is only the height to the ceiling joists and there is another foot to the top of those that I can squeeze things like ballasts and fans and possible the hoods into .
great thread btw and the nutes used here are something worth looking into, apparently they will be available in January.

still got quite a bit of veg time to decide which way Ill make this spin, so any advice will be given consideration. Pictures are being taken along the way so hopefully the results will be worthy of a grow journal

Thedillestpickle said:

Does anyone know what conditions are good for a plant to reduce stretching? Im trying to figure out how I can make a sativa as short as possible without physically touching the plant, no lst/fim/topping/supercropping

Just the perfect conditions for a plant to make it not want to stretch, Im thinking Lots of light, lower temperatures, a fan that pushes it lots. basically opposite of things that cause stretching, but are there any less obvious tricks?

any ideas are welcome

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You are better off with indica or hybrid with dominant indica if you're worried about stretching. Plants stretch if there is not enough light, they may also do this if they have too much light or heat because the light is too close. Or it may be just genetics. Satiivas are meant to be big to be mature for better yield and high effect. Note that they have 11-12 week flowering time. Most of my sativas/hybrid w/sativa dominant end up 6ft and up.

laserbrn said:

That has nothing to do with growing under MH/HPS. That's genetic.

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THC levels are definitely effected by the spectrum of light. MH tends to produce more potent buds. HPS tends to produce bigger buds.

OGEvilgenius said:

THC levels are definitely effected by the spectrum of light. MH tends to produce more potent buds. HPS tends to produce bigger buds.

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While that's true, it's not the reason that years ago people had bud that was 5% THC and now it's often closer to 20%. That does make a difference, but in general, it's the genetics that have gotten better. You can still dig a hole in the summer and plop a plant in the ground and it'll come out better today than it did 30 years ago.

I feel like the testing methods have changed as there are some heirloom strains out there that date back to the 70s that pack quite the punch..

To accomplish your goal I have two ideas.

Firstly top the plant like planned and once tops are developed go ahead and pinch the stems between your fingers. This will slow upward growth, and make the plant bush out a bit. So to combat this, about a week before flower just prune off all the lower buds that you don't want, you can prune it down quite a bit, this will cause the tops you have to get all the plants effort and boom, packed buds.


In that area i Would consider vert lighting for sure.

Second ideas to research the alternative light schedules to see if there is something that helps on sativas. If you could find out what spectrum of light produces the hormone that identifies length of night you could add a light that is not in that spectrum at night to combat stretching for light.

Haha just ideas

Hey thanks Karr sounds like some pretty solid advice, Im wondering if you can show me a link to a 600w metal halide bulb. From what I can tell you can only get 600w HPS conversion. Its an HPS but gives off more of the blue spectrum. Not ideal for me because the balanced spectrum means stretching my plants in first few weeks of flower. I had a talk with the guy at my hydro store and he was telling me there are no true 600w MH bulbs, so unless you can show me otherwise...

kindof unfortunate, an MH/HPS ballast and HPS and true MH bulbs would be awesome

Gastanker said:

Oh yeah - I use MH and HPS and I've noticed better results including closer node intervals using the MH for the first two weeks of flower (or however long the initial stretch lasts). After that I switch to HPS and the stretch doesn't seem to continue.

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what Kelvin rating should I shoot for with the MH? I was thinking 7000k but there is also the option of 10,000k bulbs... do you know which would be ideal?