Stem and stalk turning dark help!

[Reefaman]

Hey all! New grower and I’m growing Bruce Banner in a 4x2 tent with a mars 2000w tsl. I’ve been using Advanced nutes and following there feeding schedule. They are currently in veg state and I’ve noticed the stalks on them have started to get a dark colour. Any ideas on what is going on or what I might be lacking ?

 

[NewMexicannabisFarmer]

Could be genetic, many plants just do that and it is fine. Unless your plant is growing slow I would not be worried. I would like to suggest a mulching for your soil to keep more water from evaporating out. That will allow you plant to absorb more nutrients in between waterings. maybe even cut to half the dosage/plain water for one watering, that will allow the plant to make more feeder roots and be better at absorbing the nutes.

 

[Reefaman]

They are growing fast and healthy ! No signs of any issues on the leaves. They started doing that after I switched them to the new tent with the Mars Hydro 2000w and fed them the Advanced nutes, before that they where under a 600w blupurple light. Thanks for your input and advice, I think you are probably right and it could have been because the new tent dropped temperature by 3 degrees compared to the other tent. That’s a great idea, I’ll buy some mulch and give it a shot! Thanks

 

[Reefaman]

Any recommendations for the type of mulch I should use ? I assume nothing that will leech chemicals into the soil.

 

[Buds Buddy]

The stems are turning red meaning it needs Magnesium. Add Cal Mag & it will clear up. Use about 2 ml. per gallon.

 

[Reefaman]

The base nutes for Advanced nutes has cal mag in it but i can try feeding just cal mag in between feeding schedule.

 

[Reefaman]

Might not be enough though so you could be right. Thanks !

 

[AdaminCO]

I’ve always heard it sometimes can be temperature related, like a sign of stress. All of mine have always them. I just figured it was LST and high 60s at night.

 

[Buds Buddy]

I just went through the same issue 2 weeks ago. It's gone now. @MrSauga is the one who pointed this out to me and told me how to fix it. I gave up AN products last grow as they are way too expensive. I can do a complete grow for under $20 with Mega Crop & get the same results. I also only need MC & nothing more so mixing is real simple.

 

[Reefaman]

I’ve done LST and topping to them, my tent does get down to 21-22 degrees Celsius at night. Didn’t think that would be to cold though. I’ll try extra cal mag and see what happens but it does seem like nothing to worry to much about!

 

[PE636]

That's not a symptom of calcium or magnesium deficiency. Phosphorus deficiency can cause red stems but if the leaves look fine I'd say you have no issues. Many many plants do this especially as they get older it seems. Adding calmag will likely be a bad move. Good luck.

 

[Reefaman]

I would agree cause they are getting cal mag in my regular feeding. This is my feeding chart I’ve had them on after they grew 5 nodes.
The Grow and Micro both have cal mag in them.

 

[AdaminCO]

I use MC and all 5 of mine have red stems. I’ll see if I can find something on the interwebs about it.

 

[PE636]

Ya I use MC currently and have used several others brands. The red stems that you need to worry about I believe are bright red and will be accompanied by leaf problems.. Your plants look healthy and happy to me. Don't go fixing something that's not broken is my advice. Too much calmag will cause problems I promise.

 

[AdaminCO]

Just found this. Most things say red stems, no leaf issues... no problem.

Nutrient And Deficiency Table

To use the table just match up the plants symptoms with those on the table. Nutrients marked yare the problem. Find that nutrient in the text below the table for the remedy.

SYMPTOMS	N	P	K	Ca	S	Mg	Fe	Mn	B	Mb	Zn	Cu	Over Fert.
Yellow Upper Leaves	No	No	No	No	Yes	No	Yes	No	No	No	No	No	No
Yellow Middle Leaves	No	No	No	No	No	No	No	No	No	Yes	No	No	No
Yellow Lower Leaves	Yes	Yes	Yes	No	No	Yes	No	No	No	No	No	No	No
Red Stems	Yes	Yes	Yes	No	No	Yes	No	No	No	No	No	No	No
Necrosis	No	No	Yes	No	No	Yes	No	Yes	Yes	No	No	Yes	No
Spots	No	No	No	No	No	No	No	Yes	No	No	No	No	No
Growing Shoots Die	No	No	No	No	No	No	No	No	Yes	No	No	No	No
White Leaf Tips	No	No	No	No	No	Yes	No	No	No	No	Yes	No	No
Stunted Growth	Yes	Yes	No	Yes	No	No	No	No	No	No	No	No	No
Deformed New Growth	No	Yes	No	No	No	No	No	No	No	No	No	No	No
Yellow Tips	No	No	No	No	No	No	No	No	No	No	No	No	Yes
Twisted Growth	No	No	No	No	No	No	No	No	Yes	No	No	No	No

NITROGEN (N)Pale plants, red stems, smaller growth. Rapid yellowing of lower leaves progressing up the plant. Add any chemical fertilizer containing N. Treated plants recover in about a week.

PHOSPHORUS (P)Slow or stunted growth, red stems. Smaller leaves that are dark green. Lower leaves yellow and die. Add chemical fertilizer containing P. Affected leaves will not show recovery but new growth will apear normal.

POTASSIUM (K)Affected plants are usually tallest and appear to be most vigorous. Necrotic spots form on lower leaves. Red stems. Leaves appear pale or yellow. Add chemical fertilizer containing K.

CALCIUM (Ca)Lack of calcium in the soil results in the soil becoming too acid. This leads to Mg or Fe deficiency or very slow stunted growth. Treat by foliar feeding with one teaspoon of dolomatic lime per quart of water until condition improves.

SULFER (S)Plants suffering from S definciencies exhibit yellowing of new growth. Mix one tablespoon of Epsom salts per gallon of water until condition improves.

MAGNESIUM (Mg)Lower leaves yellow and may even turn white while veins remain dark green. Blades die and curl upward.

IRON (Fe)Leaves on growing shoots turn pale and veins remain dark green. pH imbalances make iron insoluble. Foliar feed with chemical fertilizer containing Fe or rusty water.

MANGANESE (Mn)Necrotic and yellow spots form on top leaves. Mn deficiency occurs when large amounts of Mg are present in the soil. Foliar feed with any chemical fertilizer containing Mn.

BORON (B)Growing shoots turn grey or die. Growing shoots appear burnt. Treat with one teaspoon of Boric acid (sold as eyewash) per gallon of water.

MOLYBDENUM (Mb)Yellowing of middle leaves. Foliar feed with chemical fertilizer containing Mb.

ZINC (Zn)White areas form at leaf tips and between veins. Occurs in alkaline soils. Zn deficiency can be treated by burying galvanized nails in the soil. Chemical fertilizer containing Zn can also be used.

OVER FERTILIZATIONCauses leaf tips to appear yellow or burnt. To correct soil should be flushed with three gallons of water per one gallon of soil.

NUTRIENT TABLE​

 

[Reefaman]

Awesome thanks guys ! I’ll stick to the regular feeding and not add any extra cal mag. The leaves are all healthy and happy. Just trying to adjust the 2000w TSL it’s a lot brighter then the 600w phlizon blurple light they where under.

 

[Reefaman]

I might have issues with the leaves, appears the leaves on one plant have discoloured a tiny bit and is deteriorating (holes in the leaves).

 

[NewMexicannabisFarmer]

Any recommendations for the type of mulch I should use ? I assume nothing that will leech chemicals into the soil.

I like to use bark from a tree in the forest, ponderosa is what I like the best because it has a vanilla smell to it and repels bugs

 

[Buds Buddy]

Not sure how you can tell it's P & not Mg. The chart also says Mg. causes Red Stems. But obviously other things can cause it too. I just want to know how you determine which thing is causing it as the Chart shows 4 things that can cause it. So your Base Nutes don't have enough NPK ? Sounds far fetched to me unless your nutes are too weak. I still think it's Mg. but treat it how you think is best.
Every grow I've ever done I've always had to add 1 - 2 ml. per gal. of CalMag to keep things in check. didn't matter if it was soil or Coco. Not sure if it has anything to do with my tap water or not, but maybe.

 

[AdaminCO]

I might have issues with the leaves, appears the leaves on one plant have discoloured a tiny bit and is deteriorating (holes in the leaves).

@InTheShed any ideas what this is.