lack of nitrogen, when to start giving more p

hi guys,

im on the 4th week of my second grow... got 6 females out of 10 so im pretty stoked! the plants are doing alright however they are starting to get yellow not so healthy leaves at the bottom.... i know you are supposed to give the plants more Nitrogen during vegetative growth but when is it time to start cutting that down? because i started giving the plants a supplement of P + K (P-8 K-4) 2 weeks into the flowering and thats when the leaves started to get yellow so a couple days ago i gave them a bit more of the fertilizer (N-7 P-3 K-5)- that i gave them during the vegetative cycle since as far as i can tell its lack of nitrogen which is causing this. Im not sure if that did the trick but Id like to know when to stop giving them N and concentrating on the P + K or do I need to give them N the wole time? btw, this happened during my first grow also - leaves turning yellow and falling off, i want to try to avoid this here.

thanks for your help!!!

Well, I don't really have a set time when I stop giving N. I just use veg nutes during veg and then switch to bloom nutes when flipping to 12/12. Makes it easy. It has been my experience that yellowing due to N deficiency starts around 5-6 week of flowering and continues to the end (indica dominant), so yours does sound a little early.

My bloom nutes do have some N in it so I don't think you should cut N out completely during flowering.

i have found that when giving nutrients to the plants ,its best to follow on the veg nutes for the first week of flowering befour changing
cheers all :)

the yellowing leaves that are falling off ,dont get too worried about it ,you will find that some of he plants leaves will fall off ,the yellow colour is just that the plant has been taking all the nitrogen from that leaf and its the plants natural way to discard the used leaf ,this is perfectly normal try not too worrie ,the only other thing that could cause yellowing is a magnesium deficency which is curable with epsom salts
cheers all :)

I had a nitrogen diff. that started about three weeks into flower (a bit early) I gave them some nitrate for a few weeks (half the reccomended dose) and things perked up very nicely. Growth also seemed to pick up. Now I am 7 weeks into 12.12 and I won't be giving them any extra N, though my blooming nutrients do have some in it. The yellowing will continue from here, very natural for it to happen. However, if you feel like it's happening too early or the yellowing is causes any stunting to the growth, shoot em up with Nitrogen! My babies def. benefited from doing so. You can always use half the reccomended dose if you feel like you would be giving it too much. Play around with it, and your babies will have a beatiful green lush color within a week of givng em additional N, mine did!

hey thanks for answering! =) ive given them alot of N now they should be fine... yeah i dont have any N in my bloom nutes so thats why i was kinda worried since i read yer sposed to give them a bit of N anyway during flowering.... thanks kids!!! =):giveflower: