Help identifying a problem

I have two White Widow plants growing outside in buckets. They were both doing great, but suddenly one of them developed spots, the tips are brown, and the leaves are curling up (see pictures). I googled this and it said to flush so I did but it is still not looking right. After more googling, it said low potassium, but then it also said to much fertilizer so I’m not sure what to do. Any suggestions would be greatly appreciated. I’ve attached pictures of the sick plant and the healthy plat (both are the same age, both have been fed/watered the same, and both are in the same location)

Welcome to ILGM.
It may be my old eyes, but the pictures look like the same plant to me besides 1 pic is a little closer then the other.
Looks like its having problems from the main stem outwards…on older growth…newer growth looks healthy still which is good.
Have you looked for pests with jewelers loop or strong magnifying glass ?
Also if you can fill out info for a support ticket I’m sure you will get better answers…lots of very helpful people on this forum to help :slight_smile:

How’s the drainage in your pots? Have you been getting a lot of rain?

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

White Widow purchased from ILGM. It germinated and was doing really well but all the sudden started getting brown spots.

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

Soil (Miricale Grow potting soil)

  • Vessels: Pots, Grow beds, Buckets, Troths


  • PH of Water, Solution, runoff (if Applicable)

use well water

  • PPM/TDS or EC of nutrient solution if applicable

Don’t know, NA. Since I’m using well water figured it couldn’t get more natural than that.

  • Indoor or Outdoor


  • Light system


  • Temps; Day, Night

Day: 85-95 (F); Night: 65-75 (F)

  • Humidity; Day, Night

Not sure, but it seems to be mostly in the 70-80 % range

  • Ventilation system; Yes, No, Size


  • AC, Humidifier, De-humidifier,


  • Co2; Yes, No


The buckets drain well, put several holes in the bottom so when it rains, they pretty much just run through with only the soil remaining wet. I did check to see if they were being overwatered but the dirt in the bucket seems to be moist but not wet (measured by putting my finger in the dirt anyway).

thanks for the feedback @T0Y, the bottom picture is the plat that is doing good (I just added it as a reference to compare to since they are sitting side-by-side and are the same age and all). The Top picture is the one with the problem. You may need to zoom in on it to see it though.

I’m having the same problem… it’s only my pots with the promix hp in them. My super soil pots are fine

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First welcome to the community. I would start by checking my pH run off and see where you’re at and make adjustments from there. Good luck

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This is most likely your problem. Soils with “time release” fertilizers are no good for cannabis cultivation. They can release too much, causing random nute excess or lockouts. You can’t flush them because every time you water more nutes are exposed.
They also give the end result a harsh flavor from all the excess nutes in the soil.


Even though you use well water you still have to check the ph my well will be from 6.7 to 8.3 and in the winter it’s all over the place.
Ph your water to 6.5 and then check the runoff of your pot this will help to show what is locked out
And like the others said to check for pest
A sick plant is a calling card for pest to move in and eat it up


I have found that MG soil also buffers to a very low PH which can flat out kill the plant. I’ve seen low 4’s and 3,000 ppm.


thanks everyone, I checked the water ph, it is 6.5 so based on the comments about MG, I am going to repot the plants in new soil (not MG) and see if they improve.


I strongly suggest getting a soil buffered for cannabis. Fox Farms, Roots Organics, Black Magic etc. It will save a lot of heartburn when you are halfway through flower.

Many of us (including me) have used MG and some do quite well. Until you gain the experience it’s best to stick with tried and true stuff before branching out (pun! haha).

Thanks for the suggestion. I was thinking that next time I may try a hydroponic grow and see if it is more predictable or not. I’m not growing great amounts, only for myself so probably only two plants is enough which should be manageable. Don’t know if that is easier or harder but after reading about it it sounds like it may be less stressful.

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The thing about hydro is you need to have a good working relationship with the nutrients you are using with an understanding of what and why. I found it extremely helpful to grow in other media before attempting RDWC. That said; the flower was the most amazing cannabis I’ve ever had. Very clean, potent and smoke was like a unicorn fart.

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