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Why Are My Seedling's Stems Purple?


New Member
DO NOT PANIC. A seedlings purple stem doesn't necessarily indicate an unhealthy plant. Please take the following possibilities into consideration:

1 - Purple Stems could be a result of that wonderful thing we call genetics, if this is the reason, you are to expect a purple stem throughout the life of the plant. It must be noted that purple stems aren't a dominant trait, and are rarely genetically induced.

2 - A baby sprout with a purple stem is almost always 100% natural. Young seedlings are still adjusting to their environment and may be slightly lacking in a Nutrient. If this is the case, healthy plants will regain their green/greenish-brown color within a few days to a week or two.

3 - If you have ruled out the possibilities of genetics and the seedlings adjustments to life, you should begin looking for a nutrient deficiency. Purple stems are commonly caused by a Phosphorous (P) or Magnesium deficiency, if there is a P deficiency you may also notice symptoms such as brittle leaves or greyish spots. To assist the uptake of Phosphorous (as well as most other nutes) you should ensure the pH is slightly acidic-- 6.0 will suffice.

Author: KidKind


Member of the Month: Apr 2009
I try to keep mine about 6.3 and I have purple stems also, nothin to worry about!

i agree dont worry about it if it looks healthy and purple stems are there might just be strain genetics! :ganjamon:


New Member
I am running Dutch Passion`s Blueberry right now,and they do have purple stems from the get go. No need to worry about it right now. Watch your ph and nute levels all will be good.


New Member
nine times out of ten if it is not extremely cold at night time then purple stems mean plant problems.

I would check my ph. If you are using soil check the p.h. of the runoff water.

Once again,purple stems DO NOT MEAN PROBLEMS all the time! Some strains are purple from the get go. Blueberry being just one. My Blueberry seedlings were not even 1 week old and had purple stems. No need to worry at this time. Watch your ph and nute levels for now. Plus, proheto8008 stated that it has to be cold outside for the plant to show colors. Not the case either. Some strains do not change color unless the weather is colder some strains change whenever. You can almost bring color out of any strain with cooler temps. But strains like Blueberry need cooler temps to bring the colors out of the buds. Alot of purple strains are like that as well. But on the flip side of things,I have grown out purple strains that did not need a change for weather to dawn it`s colors. Best thing to do when NOT knowing if there is an issue is waiting and let the plant tell you there is something wrong. Because if you assume there is an issue and you fix what YOU think is wrong and it turns out nothing is wrong,you have just made a problem out of nothing. Have patience,all will turn out ok. :rasta:
My Purple Diesel and Super Silver Haze have purple in the stems ---- no problem ---- nothing to worry about! Don't create a problem if there isn't one! Oh my quote-------


New Member
I grow three varieties and one strain has purple stalk and stems.
Do you know the strain? Have you grown it before? If you have and it was not purple before, then it could be a problem.
check it out!


New Member
This is more of a question than it is a comment or reply. I am having a slight problem controling the humidity in my grow closet. I am aware the the optimum humidity for the propagation of marijuana is 50% to 60% during the vegatative state, but the humidity in my closet stays at a constant 40%. I have since added a rather large pan of water in hopes of raising humidity levels, but so far nothing doing. So I have started spraying a little water directly into my grow room and that really does work for about two-hours, But i feel like that all I am doing is putting a band-aid on an bleeding atery. Any suggestions would be extremely helpful. Also th ph level is around 5.5 to 5.75. Is this detrimental to my babies.


Well-Known Member
i like to use the soil premiere pro mix bx because it has ph control in the soil and contains all these in it
Canadian Sphagnum Peat Moss (75-85 % / vol.) Macronutrients
Perlite – horticultural grade Micronutrients
Vermiculite Wetting Agent
Dolomitic & Calcitic Limestone (pH adjuster) and mychorizae *idk if spelling is right''


New Member
I am growin tony the tiger and started with 5 seeds and turned to
6 =) and one of my plants has a purple stem and then a new not to long ago like 3 days a new plant sprouted up and its stem was purple so now i have 7 plants and idk how to explain this and no one i ran in to has an explination for this could this be
a result in a female plant there almost a month old are my oldest plants only 2 of 7 plants stems are purple help thx ??

Genesus 29: veruse 1: behold i have given you every green herb bering seed.

soylent green

New Member
Thanx a bunch Wingman420. Where might I find one of these cool mist vaporizers?
Not sure where you are from but walmart carries them. Look around the pharmacy area of the baby area. I use a steam vaporizer myself for normal veggie plants but I also grow with fluorescence so heat is not as much of a problem and it was what I had on hand.


New Member
Keep it at 40% it'll help keep from getting powder mold.
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