Sick Plant! Black leaves

Discussion in 'Sick Plants and Problems' started by realPragmatist, Aug 14, 2017.

  1. #1 realPragmatist, Aug 14, 2017
    Last edited: Aug 14, 2017
    What is going on with my plant? I have others in the same area that I've fed/watered/etc all the same as this one but this one is getting sick. The others are fine.

    These are all of the same plant. 20170814_124620.jpg 20170814_124624.jpg 20170814_124630.jpg

    EDIT: Forgot to clarify, it's an outdoor grow in ProMix soil. Been feeding them foxfarm Grow big. In the last stages of fighting off spider mites and had a little too much water the other day.(Was beautiful out so I watered them then it poured afterwards :-/)
  2. I believe your plant is showing potassium def
    • Like Like x 1
  3. Would giving them FoxFarms "Grow Big" help that? It's about all I got on hand except blood meal and bone meal.

    I can't tell from the label if it's good phosphorus or not. (I'm a bit dense sometimes lol)
  4. I think I answered my own question regarding the Grow Big. I finally found an explanation of the 0-0-0 numbers.(I'm new, first grow ever) The grow big is only 6-4-4, but the Steamed Bone Meal(Happy Frog brand) is 3-15-0. So I should give it the bone meal correct? Is there any trick to getting the bone meal to deliver quicker than normal? Also how much should I use? They're in 18 inch culvert that's prob 2-3 ft tall. I'm guessing 10-15gallon containers. The directions on the Bone meal say to give it from 1/2 cup(for 1-2 foot plants) or 3/4 cup(for 2-3 foot plants)
  5. Your in veg so I would give them the grow big man
    • Like Like x 1
  6. That bone meal is for flowering and is high in phosphorus not potassium
    • Like Like x 1
  7. I kept thinking phosphorus for some reason lol. I swear you're first post said that! haha

    Thank you for the help. I'll feed it some tonight.
    • Like Like x 1
  8. Yea no I said potassium haha, have you feed them nutes at all before ? And no problem I enjoy helping others with this stuff it's a hobby of mine , I'm a disabled combat veteran and believe it or not growing cannabis has saved my life in more ways than one . So I'm always up to help others with the journey !!
    • Like Like x 2
  9. They've had some of the "grow big" not very much. I'd just picked it up. I started using Miracle Grow's Tomato food until everyone (literally everyone that I talked to about growing lol) said do not use it. That was prob 3 weeks ago. I picked up the Grow Big and had been feeding them pretty regularly(added in some blood meal every now and then. Followed the directions on the Grow Big 3tbsp per gal. Same with the blood meal when I used it, 1/2 tsp per gal). The tips on 3 out of 4 plants started yellowing last Thurs(5 days ago) and I understood that to be nutrient burn so I laid off food until this started happening. Gave the plants roughly a third of a gallon that had been mixed 3tbsp of Grow Big.

    I've been using rainwater to water them for the most part. Sometimes I ran out and used the hose water(From a well, not city).

    Friday when I noticed the yellow tips, I'd given each plant 1 1/2 gallon of straight water. It ended up raining too(not too too bad, but not just a mist). Sat I noticed gray fibrous "mold" on the top of my soil. I'd scooped it out and churned up the topsoil and laid off watering for a few days. Everything went fine for a few days. The yellow disappeared, the mold didn't come back. Until I noticed this. Like I said, it's only the one plant. It was the one with the least amount of "mold" too, like 2 spots the size of a quarter(well away from the plant).

    And thank you for your service as well. I'd assumed the 'Veteran' part of your name referred to growing, not military ;)

    EDIT: Forgot to add that I'm using Neem oil with regular dawn dish soap for the spider mites.
    • Like Like x 1
  10. I i believe this to be very believable :D think it has saved as many lifes as cancer kills :D
    • Like Like x 1
  11. Well the Veteran refers to both actually lol but yea I would give them plain water for a bit see if it gets worse or better . The plants won't starve and you can get a grip on whether you need to feed or not .
  12. Are you adding calmag at all ?
  13. I have not.
  14. You're gonna need calmag if you are running promix. To me this looks like a phosphorus deficiency.

    Sent from my iPhone using Grasscity Forum
    • Agree Agree x 1
  15. Agree with phosphorous deficiency because the affected leaves looks slightly tinted purple with black. The curling of the sides of some of your leaves indicates heat stress.
  16. I wouldn't think it's too hot for hasn't gone above 90 all summer so far(northeast). I would think that's not too hot for them right? They do get a lot of sun where I have them, pretty much from sunup to sundown.

    The plant seems to be coming out of whatever was wrong with it. I'd fed it the Grow Big a few times and just left it alone otherwise and it's growing new greener leaves all over it. Thank you guys for the help!

Share This Page