Growth during flowering

Im trying to plan when to start flowering 2 northern lights plants. The only issue is that i haven't found much info on how much they grow during flowering. Im using 600W HPS, very little nutes NPK 18-9-26. Does anyone have an idea on how large their expected to be by harvest from the photos?

How tall are they now? Well since they are northern lights, which is mostly indica dominant then you can expect them to double in height. If you have height issues I suggest you try some lst on them. They seem pretty bushy already so some lst would open get up anyway.

Once they go into flowering they will stretch a bit.....Depending on strain it will vary from a 1/2 inch to 6 inches....They only grow during the first 7-10 days of the flowering process, after that the plant will quit growing and will put all its energy into growing the flowers

Good information, will help a lot. They're about 1ft right now. Also, even if the plant only grows for a week or so during flowering, does root development also continue during flowering? Will i have to worry about transplanting once flowering has begun if the container currently is a "perfect fit" for the plant?

putdust said:

Good information, will help a lot. They're about 1ft right now. Also, even if the plant only grows for a week or so during flowering, does root development also continue during flowering? Will i have to worry about transplanting once flowering has begun if the container currently is a "perfect fit" for the plant?

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Mmm, Interesting questions and good ones too!

First off lets clarify something quick like. The plant DOES continue to "grow" throughout the flowering.....The major amount is done in the first few weeks for most strains but, Heavy Sativa's take a longer stretch period.. Indica's will about dbl in size in bloom, while Sativa's can even triple in size! Many crosses can fall in between the two.

In all growing, yes the roots will continue to grow in bloom but, at a very reduced rate the deeper it gets into bloom. Like on a bell curve, if you will.
I always did up potting as I saw need. The last up potting is done 8-10 days before the flip to flower. This gives the roots time to spread into the new soil and give space for them to fill as the flowering period continues. This is naturally for soil grows..
Never intentionally up pot during bloom! This is the BEST way to ensure root space and no "rooting stress" during bloom!

Now you know.

Good Luck

P.S. You should up pot the plants you have NOW! They are looking to be at that point in size relation to the pot their in....

Callisto405 said:

Once they go into flowering they will stretch a bit.....Depending on strain it will vary from a 1/2 inch to 6 inches....They only grow during the first 7-10 days of the flowering process, after that the plant will quit growing and will put all its energy into growing the flowers

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absolute bullshit.

Callisto405 said:

Once they go into flowering they will stretch a bit.....Depending on strain it will vary from a 1/2 inch to 6 inches....They only grow during the first 7-10 days of the flowering process, after that the plant will quit growing and will put all its energy into growing the flowers

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Negative, some plants will triple, yes I said triple in height.

putdust said:

Good information, will help a lot. They're about 1ft right now. Also, even if the plant only grows for a week or so during flowering, does root development also continue during flowering? Will i have to worry about transplanting once flowering has begun if the container currently is a "perfect fit" for the plant?

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Allow me to to share something I've shared with a few others. I should patent this formula, but eh not like that. Hope you like math.
http://rollitup.org/Journal/Entry/the-when-to-flower-formula.33464/

putdust said:

Im trying to plan when to start flowering 2 northern lights plants. The only issue is that i haven't found much info on how much they grow during flowering. Im using 600W HPS, very little nutes NPK 18-9-26. Does anyone have an idea on how large their expected to be by harvest from the photos?View attachment 3636870 View attachment 3636871

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How long have they been vegging? I don't flip my plants until they reach close to 30 inches

I suggest transplanting to a larger pot; say 5 maybe 7 gal if you have the space. Let them veg for another 3-5 weeks while you LST & supercrop the tallest colas; keep spreading them branches out. They will grow very fast under a 600w after transplant to a larger container. As a rule of thumb most plants will grow another 30% or so during flower phase so when the plants are about 2/3 the size you want at harvest it's a good time to flip em. 1 to 4 oz per plant is a reasonable expectation of yield depending upon how they are trained under a 600w but worry about keeping them healthy & yields will come.

Thanks for all the help! i've transplanted the left (smaller) one yesterday and changed to 12/12 as im worried about height problems once flowering starts if i let them grow any more. I've looked at the formula dgthumb linked to, which gave me a very good guide to base this decision on. they've been vegging for around a month and a half. Im thinking a larger pot for the one on the right wont fit in the grow space, so im gonna have to take my luck with flowering in the same sized pot.

Also, recently i've noticed a few scattered leaved displaying signs of deficiencies/over-nutrients. This is my first grow, and although ive looked online i cant pinpoint it to one problem. Ill post pictures later today to see if you guys can help identify them. (https://www.rollitup.org/t/help-identifying-leaf-issues.903802/) Thanks again for all the great advice.