Dark Splotch on Leaf of Seedling

Discussion in 'First Time Marijuana Growers' started by didjdudjs, Oct 30, 2014.

  1. After a few minutes of searching I haven't found anything in the "Absolute Beginners" section that really pertains to my current situation. It is thus.

    My seedlings, at one month, are VERY tiny for their age (about 4-6" tall) and only have 3 sets of leaves. I figured it was because of the Miracle Gro potting mix, which I now understand is bad for cannabis seedlings due to the time-release nature of its nutrients.

    I just transplanted the girls yesterday into their final containers, and opted this time to use a soilless mix (minus the vermiculite). While I was transplanting them I noticed that one of my tallest plants had a dark greyish-purple splotch. I was concerned but decided to wait till morning before investigating.

    The splotch has tripled in size overnight. I took a picture and am attaching it in this topic. Can anyone offer any wisdom? Is it a mould or fungus that could hurt the rest of my plants? Should it be removed? Dare I remove a leaf from a seedling so small?

    Whatever it is, it's spreading at a noticeable rate every hour, so I need to know as quick as possible. Thank you!

    (Apologies for the image quality. This is how my Galaxy S5 lens reacts to the HPS lights I guess)

    Attached Files:

  2. It's really hard to tell with that picture. Does the new growth look health? If so I would just let her settle into the new soil for a bit without trying to fix anything.

    Sent from my iPhone using Grasscity Forum
  3. Don't take pictures under HPS lights, if you take a picture under normal lighting, we can help you much better.
  4. Knock the light off and take a pic
  5. Apologies. Here it is under normal skies.

    Attached Files:

  6. The leaves look very pale, what type of water and nutes are you using...?
  7. They were in Miraclo Gro potting mix for the first 29 days, and I didn't find out until later that it was bad for them. The only nutrients they've been getting is from the time-release nutes in the MG. I have been watering with plain tap water the entire time. Yesterday I transplanted them into much larger containers of soilless mix (lacking vermiculite). I figure it's going to be a few days before the roots start to expand into the rest of the pots now, where they're going to get Mother Earth Super Tea organic nutes mixed with their water at 50% strength.
  8. 1. Any reason you're using HPS for veg?

    2. Are you ph testing your water?

    3. Any nutes?

    4. What's your medium and its ph?

    The peeps are right. They look pale, and that purple spot could either be light burn or nute burn. Has the spot changed in colour at all since you took the pic?

    Sent from my iPhone using Grasscity Forum
  9. Tap water needs to be pH'd. Just give her properly adjusted water for a while and see how she does. What's at the bottom of the pic? Did you damage the stem?
  10. #10 didjdudjs, Oct 31, 2014
    Last edited: Oct 31, 2014
    There's 8 of them sitting on a table surface of 2x2ft in my closet. Top of the plants are about 12 inches away from my 150W HPS bulb. Cooler air from the patio window mixes with warm open closet to make the leaf-level temperature maintain a steady 75-80 degrees F. Nutes are Mother Earth Super Tea mix (organic) at only half strength, because the roots are still bound around shitty Miracle Gro potting mix. They're now in a soilless mix medium (not sure exactly what, but the lady at the grower's supply told me it only lacks vermiculite, which means I'll have to water more often). Waiting for the roots to spread into the soilless mix and see if the plants do better. It was during the transplant yesterday that I noticed the splotch. It's now covering almost half of the leaf. Hasn't changed color. Mostly dark grayish purple. There's a dry-sort of look to it.
  11. Sorry andyGROW, didn't see your comment until just now. That's the top of the straw I used to splint them when they were too skinny. The stems are all pristine.
  12. OP here, just had to take measures into my own hands and snip off the leaf entirely. Snipped off the opposite leaf to match. Including a final photo here to show how bad the dryness got before I decided not to wait any longer.

    Attached Files:

  13. They're not getting enough air, leaving doors ajar and windows open isn't enough. You need a proper extractor fan. All living things are made mainly from carbon. Plants get theirs from air, without it they'll give poor growth/yields...

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