Purple stems. Stress or UV protection?

[Solarscar]

Curious about this one. I have had stems after about 8 weeks in veg then it has really ramped up the purple stem action. I am hearing that it’s stress related, but I don’t feel I have starved them or under watered them. It seems that when looking down on them as the light would, that the purple stem action is primarily on all the exposed stems from training. Curious what your thoughts are on it.

 

[mysticepipedon]

Are you talking about the "leaf stems," aka petioles? If so, I agree. Red/purple seems to be from light exposure. Colorful stalks can mean there's a P problem, but I seem to get purple stripes that don't indicate anything.

 

[Solarscar]

I have both. The meristems are super purple, so much they are turning brown/woody. There is no purple on the areas where I rolled the stem to lst them 2 months ago. I assume the parts of the stem aren’t seeing purple is because they turned woody on those areas first therefore protecting it? I’m not seeing any issues with growth though. An observation that I am wondering if I should do something different next time around? I bottle fed them salt nutes at a 1/2 to 1/4 strength once a week or every 5-8 days since about 4 weeks into veg. I’m think I should step that up next grow? They are 47 days into flower now.

 

[Xolivo21]

Check your waters PH. Might have a bit of nut. Lock going. From my experience sometimes it's genetics but it could also be that the ph is off. I was shown that you want to see nice vibrant green stems. Which means nice path for food.

 

[Solarscar]

I’ve been checking ph after added nutes and have been adjusting it to about 7 since I noticed my run off ph was around the 6 mark. I have been running plain water until run off then watering nutes in to be sure I’m not overloading it up. I am starting to get a fade right now, but I expected that. Colas are fairly nice, just hope they are gonna far up over the next 3 weeks or so. If there is a nute lockout, would I see less bud swell?

 

[Xolivo21]

In my opinion. 7.0 is high. I keep my girls between 5.5 and 6.0. I've found this to be a sweet spot.

As far as swelling your plants are still getting food. If it's nut. lock. Just not as much, so you will still get swelling. Just think of it as playing a game with one hand tide behind your back.

 

[Solarscar]

When checking run off ph it’s always on the low end. My thinking was feeding it a higher ph to average it out. Is it possible the ph changes overtime when it the soil?

 

[Neuro]

When checking run off ph it’s always on the low end. My thinking was feeding it a higher ph to average it out. Is it possible the ph changes overtime when it the soil?

Oh, you've opened up a can of worms here. It depends on who you ask. My experience is yes. If you want a better idea of your pH in the root zone do a slurry test as they tend to be more accurate than run off. Dig down 2 in and mix equal parts of medium and distilled H20. Magnesium deficiencies can also cause purple stems whether from lockout due to pH or just not enough. In that case though, you'd see yellowing in the leaves. They look healthy though.

 

[CreekWolf]

I have both. The meristems are super purple, so much they are turning brown/woody. There is no purple on the areas where I rolled the stem to lst them 2 months ago. I assume the parts of the stem aren’t seeing purple is because they turned woody on those areas first therefore protecting it? I’m not seeing any issues with growth though. An observation that I am wondering if I should do something different next time around? I bottle fed them salt nutes at a 1/2 to 1/4 strength once a week or every 5-8 days since about 4 weeks into veg. I’m think I should step that up next grow? They are 47 days into flower now.

I'm having the same issue atm with one of the girls. And the one it's happening to she has been in veg for 8 weeks but had to keep cutting her back so the others can catch up. How did yours turn out @Solarscar ? I'm tossing up whether to move her out and replace her before flipping
Cheers