Seedling turning yellow and burnt tips

Hey guys my first time growing and after much research I’m still not sure what I’m doing wrong, outdoor grow in coco. I will usually water a cup everyday and have currently been mixing a small dose of nutes into rain water with a ph of around 6-6.5 any tips would be great.

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Welcome to the forum.

pH should be ~5.8 in coco. Be sure to adjust the pH after you’ve added any supplements you are adding to the water.


Welcome to the forum, your in good hands.

I’m sure we can help identify what’s going on with the little one, first thought too much water and depending on what medium your using to grow in it probably doesn’t need any nutrients yet. Seedlings don’t have much of a root system so they are very easy to overwater, usually a light mist in a clear container placed on top of the sprout is all the water it’ll need in a day or 2.


So we can get to know your methods and your plant a bit better as well as effectively make accurate and suggestion take a moment, and answer these questions as accurately as possible

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 (photo or auto)
-Age of plant
-Method: Soil w/salt, Organic soil, Hydroponics, Aquaponics, KNF
-Vessels: Type and capacity of container (fabric, plastic, etc)
-PH and TDS of Water, Solution, runoff (if Applicable)
-PPM/TDS or EC of nutrient solution if applicable
-Method used to measure PH and TDS
-Indoor or Outdoor if indoor, size of grow space
-Light system List brand and wattage/spectrum
-Actual wattage draw of lights
-Current Light Schedule
-Temps; Day, Night
-Humidity; Day, Night
-Ventilation system; Yes, No, Size
-AC, Humidifier, De-humidifier,
-Co2; Yes, No

If growing Hydro some additional questions:

-DWC? RDWC? Autopots? Ebb and Flow? Other?
-Distance of liquid below net pot (DWC)
-Temperature of reservoir
-TDS of nutrient solution
-Amount of air to solution

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

Post all your questions for this grow in the same thread you’ve started so we can easily review information about this grow.


Ok great should I punch some holes in the top to let some air in also ? Below is a pic of what medium I’m using



Your seedlings are asking for more light. It’s why the stem is so long.

Keep in mind that coco becomes hydrophobic if left to dry out. It should be kept damp.

  • don’t know what strain. It is a photo
    -Age of plant is about 5 weeks
    -Method: Coco peat
    -Vessels: Fabric pot about 8 litres
  • ph is around 6-6.5
    -PPM/TDS or EC of nutrient, does not get monitored
    -Method used to measure PH is a ph test die kit with the colour chart
    -Current Light Schedule 12 hours of sunlight
    -Temps; Day 25-30c , Night 20-25c
    -Humidity; Day 80%, Night 80%
    Co2; No

Yes I have had to put more coco around the stems as they were nearly falling over.

Are they getting several hours of direct sunlight every day?

They get an good 6 hours of direct sunlight and maybe about 4 with the sun moving around some trees/ shade in the afternoon

I expect the issues you have are due to the pH being too high. The plant has a hard time absorbing nutrients in coco with too high of a pH. Here’s a chart of nutrient absorption in coco, which is considered a hydro medium. The plant cannot absorb potassium, phosphorous, magnesium, iron, and boron. 5.8 is the sweet spot for a coco grow.


@Freebirdmikes dude you have been doing a ton of reading here. Three days in a month is dedication to the craft. :slight_smile: It’s awesome!


No holes, you want to increase humidity directly around the plant so she can hydrate easily. For coco you’ll want to keep it moist all the time, and be very easy on the nutes for the next week or 2. New growth looks okay, but could be better.
Ph over 6 is too much for coco this is likely your biggest issue, I believe 5.8 is the consensus.
Ppm/ tds tests are crucial. This is how you determine how much food your giving your plant. It’s a fine line between enough and way too much, by the looks of things too much has happened already.
5 weeks old? Concerning a bit for its size, seems to have been a bit stunted… . Current pics?
Lanky stem, this indicates the plant isn’t getting enough light. Would you mind letting us know what your using for lights? 12 hrs sunlight? If it’s through a window it’s probably not gonna cut it, residential windows are designed to block harmful rays from reaching occupants, it also blocks it from the plant.


@MidwestGuy ! Can’t have too much of a good thing :grin: I really enjoy being able to assist others with issues, I wish I had this when I started growing, what a great resource this place is. Still learning stuff each time I’m here (multiple times daily). I’ve always grown outdoors but the last 3 years I’ve been #2 guy in a pretty large indoor operation, 2 houses each one homing 60 plants in each growth stage supplied by in house mothers. We dissolved the grow a few months ago and I miss it terribly. Learned so much yet there’s still so much I can learn and improve.
Thanks for the callout growmie!


This is just my opinion, SO, if this is your first time growing, you should probably not use coco. I’ve been growing for years, and won’t use coco because it seems to be very particular. I’d suggest using fox farm happy frog. You’ll have a lot less headache, and probably better results.

Howdy!! Welcome to the Forum!!! :smiley:

With coco you have to add cal-mag with EVERY watering/feeding.

You should feed at least once a day.

Next time mix a bunch of perlite in with the coco, 30-50% perlite.

Growing in coco, especially starting seedlings, requires lots of attention and care. It is completely different than growing in soil.

To learn everything you need to know about growing in coco, go to cocoforcannabis dot com. Sorry for the broken link but thats the way it is these days, even educational links aren’t allowed apparently.


Agreed @CMichGrower hydro can be unforgiving. Soil naturally acts as a buffer so you can get away with some mistakes Here and there.

Hey mate my coco is actually buffered with cal mag.