Stem damage, by unknown cause

Hi, I am first time grower and things were going well until this morning, The plants all look as if something is gnawing the stem at the base. I have no idea what is causing this and am badly in need of advice before I loose them.
All help and advice gratefully received.

Don’t hold me on this but I believe what you have is called damping off. Cause is being to wet in soil. But you look like you are in hydro. Maybe @Myfriendis410 will know more


Do you have any “before” photos?
it almost looks like you don’t have your root fully covered. Is your plant falling over? It looks like your running a hydroponic system - have you checked your roots? Is your plant generally viable or does it look like it’s suffering? How old is your plant?
If you can give me a wee bit more information I’d love to help you work through this!

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what is that dark brown thing in the lava rock?

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Looks like a Rapid Rooter.

How high up is your reservoir with respect to the net basket? It should be 2" or so below and the roots dangle down into the rez. @HornHead called it: not sure what you should do: maybe try to support it and allow the base of the stem to air out. There’s a good chance you are going to lose them though.

COPY/PASTE the below list into your forum post.

Answer these simple questions the best you can.
If you do not know, or do not use something; Just say so; Or post
NA (non applicable)

What strain, Seed bank, or bag seed

Method: Soil w/salt, Organic soil, Hydroponics, Aquaponics, KNF

Vessels: Pots, Grow beds, Buckets, Troths

PH of Water, Solution, runoff (if Applicable)

PPM/TDS or EC of nutrient solution if applicable

Indoor or Outdoor

Light system

Temps; Day, Night

Humidity; Day, Night

Ventilation system; Yes, No, Size

AC, Humidifier, De-humidifier,

Co2; Yes, No

Always try to upload a clear picture of any issues you may have to allow the community to assist you.

Add anything else you feel would help us give you a most informed answer should be included. Feel free to elaborate, but short and to the point questions and facts will help us help you in a more efficient manner :slight_smile:



Hi, Thanks for taking the time to answer my query, here is background information on my set up and it’s location, also why I am growing.
Plants are White Russian from a seed bank and are feminised, reason for growing is to make RSO as I have prostrate cancer and as a sleep aid. Not for smoking or recreational use though my son might think differently!
The system is hydroponics in a grow tent, PH 5-6, EC 1.6, RH 60% and temp 21-25 degrees are all running at I hope are the correct levels. I use a humidifier to keep the RH correct and also have a small heater in the event of it becoming cold during the plants night. I have an 18 hour day and a 6 hour night cycle and have a supply and extract air system with a diffuser for the supply air to make sure plants are not wind damaged .
System is in a secure shed but I do have to walk through grass and plants to reach it.
Plant are about 4-5 weeks old, germination and initial growth in peat pots then put into tent in baskets filled with clay beads, roots are now well developed and into the nutrient solution The solution is above the bottom of the basket but well (3-4") below the peat plug.
I do not know much about gardening, I am limited to runner beans , a lawn, pots, hanging baskets and a flower bed for she who must be obeyed!
Having read up more on this site and using google, I am beginning to think Cut worms! The shed has vents through which the moths could get in, also perhaps on my shoes though I normally take them off when I am in the tent. And though all the entrances to tent are as secure as possible it is certainly not bug proof!
So I have just bought a spray and treated the plants, I have placed a cardboard disc round the stem to catch any run off from the spay and keep it out of the tank. Hopefully if I kill any beasties I will be able to see the corpses! I do not like chemical gardening an if I manage to sort this out will be trying one of the natural recipes I have seen on the forum to keep them bug clear
Tomorrow, my plant are asleep now, I will raise them up in the tank as advised by myfriendis410.
Thanks for all the comments and advice so far, hoping the info above is of help.

It sounds like you have your environment controlled quite well. The only thing that raises a flag for me is your humidity. 60% is on the high side. You’re putting yourself at risk for fungal freeloaders like powdery mildew. I don’t think that’s the reason for your stem damage but considering your plant essentially has an “open wound” a fungal infection could be quite detrimental; not just for your plant health, but for your actual health.
I absolutely extend my love and positive energy your way regarding your cancer diagnosis. However, growing and consuming cannabis is definitely the right way to go. It doesn’t just help with managing side effects from the chemo/radiation and the disease itself, there have been studies done indicating that cannabinoids can/do specifically target cancer cells and instruct them to commit suicide. It’s called cellular apoptosis. This cell death is different from the cell destruction caused by chemo and radiation. You know that chemo and radiation destroy cancer cells but that they have no discretion and kill any other cell they can get their hands on. Apoptosis is an intracellular instruction that directs the cell to kill itself and it does so without killing or effective the healthy cells in the area. This leads to tumor disintegration.
Please don’t misunderstand me by thinking eating edibles, smoking a joint, vaping or consuming an oil here and there will cure your cancer. The apoptosis finding I mentioned was the result of a study and I don’t fully understand the route of administration or anything like that. I simply mean to imply that growing and consuming cannabis has actual benefits and potential benefits that science recognizes but still doesn’t even understand.
Cannabis is a gift from the Earth to all of us. :slight_smile:

But back on track - it sounds like you’ve got great advice from the members, have taken some good steps to correct and have a good plan to move forward! My only suggestion at this point, like I mentioned above, is to lower your humidity to around 45%. If not now, then DEFINITELY before you begin to bloom. That humidity is a perfect level to grow powdery mildew and bud rot.

Be well & Happy growing!! <3

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image Your issue if the height of your plant in the medium your using.

Make a mound not a flat surface, the plant should be higher then the basket. The aerogarden/ rapid rooter your using for the seedling is killing your plant. You may only see this one out of every 10 plants but it will happen again and again.

I speak from experience the plant is dead, clone it now while you still have time.

Cut every branch and clone them all

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If you keep your temps between 23-25, 60% RH is great. Excellent VPD. If you let it dip down, try 57%, with 60% being the highest.

Once you’re in bloom, rh should drop. A couple weeks before harvest, I allow mine to drop significantly lower than what the chart says

VPD Chart Veg:
Stay in green zone

VPD Chart Bloom:

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this is your problem buddy, as @Myfriendis410 stated it should be at least an inch and a half bellow the bottom of the pot…:slightly_smiling_face:

edit are you using anything for your roots, peroxide, bacteria etc?


Your water level is to high…
Are you top watering…?
Plants are damping off…
Trunk rot…
Water level should be 2 to 3 inches below your net basket…:wink::+1:


Thanks for all the helpful advice, this is a truly great forum. I am taking this on board and will report further on the effects. :grinning::grinning:

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As promised a report on my plants after all the good advice I received. The problem of the damaged stems was caused by me piling the media too high and when the fresh air supply sped up it was causing the plants to move about and the media was grinding away the stem. I noticed this happening when I spent an hour or two working and watching them. I have lowered the media , assembled some tripods to support the plants and moved fresh air diffuser so the plants do not move about so violently! Even the badly damaged plant is starting to look better all be it the first two leaves are turning yellow but fresh growth is appearing. So entirely my fault! Thanks once again to all the people that helped with my problem, you supplied a lot of advice and information that will be very useful with this and future grows!