Brown spots on upper Leaves

C

Cheesed_Jay

Member
Hello,
I just noticed these dark brown spots appearing on some of the top fan leaves and even a sugar leaf! Also closer look shows edges of leaves starting to brown a bit. Could anybody advise what deficiency this could be?
Using 5 gal FFHF with Dr Earth flower girl 10 tbsp every 3 weeks since light switch. Have done 2 feedings in flower about to do last one end of the week.

You may also notice on the overall picture some lower yellow crispy leaves. That was I believe an old potassium efficiency that was corrected in the last feeding as the leaf damage stopped progressing, so I don't believe it's part of this.
 

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LewberDewber852

LewberDewber852

Well-Known Member
cannabiscrusader said:
I use dr earth too. I always add worm castings when top dressing. I also ammend with the three ite's. Dolomite, langbeinite, and azomite
Click to expand...
I’ve been seeing langbeinite popping up more on here for and additive and am interested to try it on my next grow. I run into these “rusting” issues in flower as well with my FFOF.
 
LewberDewber852

LewberDewber852

Well-Known Member
Cheesed_Jay said:
Hello,
I just noticed these dark brown spots appearing on some of the top fan leaves and even a sugar leaf! Also closer look shows edges of leaves starting to brown a bit. Could anybody advise what deficiency this could be?
Using 5 gal FFHF with Dr Earth flower girl 10 tbsp every 3 weeks since light switch. Have done 2 feedings in flower about to do last one end of the week.

You may also notice on the overall picture some lower yellow crispy leaves. That was I believe an old potassium efficiency that was corrected in the last feeding as the leaf damage stopped progressing, so I don't believe it's part of this.
Click to expand...
How many weeks since flip?
what strain?
 
C

Cheesed_Jay

Member
Thanks all! Yeah FfHF sucks for calcium.... Had issues with tomatoes with it outside this year, the dreaded blossom end rot.
Thanks I'll give it a nice dose of Cal mag, any suggestions on how frequent to dose Cal mag at this point only maybe 4 weeks away from the end?
 
Cpappa27

Cpappa27

Well-Known Member
Give her a full dose of cal mag probably ever other watering till finish. Those brown spots may be too much potassium and not enough phosphorous.
 
C

Cheesed_Jay

Member
Hello,
So about 3 days ago I did the final feeding of flower girl Dr earth. Two days before that I did a calmag dose, 1/4 gallon of water and 1 ml of calmag(so equivalent to 4 ml per gallon) which was a nice dose. 2 days after the doctor Earth feeding(yesterday)I did a very light calmag dose 1/4 gal of water to 1/4ML calmag(1 ml calmag to gallon equivalent)
However as you can see from the pictures the symptoms has advanced a good bit and starting to spread to other leaves.
I'm hesitant to add too much more Cal mag I'm only like two or three weeks away from harvest. Plus today I noticed a few small burning spots on some of the lower leaves. I know Cal mag can burn especially at this point in the grow.
Am I better off leaving well enough alone at this point and hoping to get to the end? Is it a big risk of deficiency will spread to the buds?
The flower girl has plenty of phosphorus and potassium, and being that I just fed it I don't think I have too little but maybe too much. The symptoms seemed to accelerate after the feeding. Plus flower girl has calcium and a bit of magnesium in it, though I don't know how much will actually get absorbed before the end since it's slow release.
 

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Last edited:
amneziaHaze

amneziaHaze

Well-Known Member
www.growweedeasy.com

How to fix Cannabis Calcium Deficiency (Ca) Pics & Symptoms

Calcium deficiencies cause tiny brown spots that appear on new and middle growth. Learn how to fix this problem for good!
www.growweedeasy.com www.growweedeasy.com
whats your ph?

  • Grower is using filtered or reverse osmisis (RO) water to feed plants – the amount of calcium found in tap water varies, but some tap water has enough calcium to prevent calcium deficiencies
  • PH is Too Low – If grow medium is acidic (below 6.2 pH, Calcium can get locked out even if the Calcium is physically there)
  • Growing cannabis in hydroponics or coco coir without supplementing extra Calcium (it’s recommended to use a Calcium supplement in hydro or coco)
  • When growing in soil that hasn’t been supplemented with calcium (usually from dolomite lime)
  • Too much potassium can also sometimes cause the appearance of a calcium deficiency
  • Outdoors – calcium deficiency is more likely to appear in acidic soil (below 6.2 pH)
  • Cheesed_Jay said:
    The flower girl has plenty of phosphorus and potassium,
    Click to expand...
 
C

Cheesed_Jay

Member
amneziaHaze said:
www.growweedeasy.com

How to fix Cannabis Calcium Deficiency (Ca) Pics & Symptoms

Calcium deficiencies cause tiny brown spots that appear on new and middle growth. Learn how to fix this problem for good!
www.growweedeasy.com www.growweedeasy.com
whats your ph?

  • Grower is using filtered or reverse osmisis (RO) water to feed plants – the amount of calcium found in tap water varies, but some tap water has enough calcium to prevent calcium deficiencies
  • PH is Too Low – If grow medium is acidic (below 6.2 pH, Calcium can get locked out even if the Calcium is physically there)
  • Growing cannabis in hydroponics or coco coir without supplementing extra Calcium (it’s recommended to use a Calcium supplement in hydro or coco)
  • When growing in soil that hasn’t been supplemented with calcium (usually from dolomite lime)
  • Too much potassium can also sometimes cause the appearance of a calcium deficiency
  • Outdoors – calcium deficiency is more likely to appear in acidic soil (below 6.2 pH)
Click to expand...
I had tested it a day before adding Cal mag the first time, it was a tablet soil PH testing kit. It was a little old too. It was hard to read but it looked like it came out around 5.8 maybe 6. Definitely wasn't overly acidic but a little low. I've read testing runoff isn't very accurate so I haven't even done that. I stopped phing my water at this point too.
I was hoping between my alkaline tap water at about 7.8, and the cal mag it would have brought the pH up some. Today I'm going to look into how to test the pH better of the soil including any suggestions I may get, and order whatever I'm going to need.
 
C

Cheesed_Jay

Member
cannabiscrusader said:
I haven't used cal/mag since switching to dr earth a few years ago.
Click to expand...
Good to know! I unfortunately didn't use Dr Earth from the beginning I started with flower girl at transition. So a lot of that slow release calcium wasn't released as if I started from the beginning. Calcium carbonate takes a while to release I know. I just used FfHF and some epsoma 533 I had laying around in veg, overdid it and had to flush right before flower. Then flower girl from then on every 3 weeks.
Next grow going to be more consistent.
 
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C

Cheesed_Jay

Member
Well I got the testing kit back out. I tested pH with multiple testing methods via the slurry sample collection method. Everything came out around 6.5 somewhere between 6 and just below 7. pH seems in range to not cause problems.
While I had a good slurry I tested NPK I had capsules. Definitely no high amounts other than nitrogen was a bit high. The nitrogen being high is not a great thing late in flower that's for sure but it doesn't really explain this issue, I think It got a bit high overusing worm castings, but no real nitrogen toxicity symptoms maybe some mild burning I just noticed today, but again not the same issue. Probably from the Cal mag too cuz that has some nitrogen.

The phosphorus was low which I didn't understand because I'm using flower girl which is high in phosphorus. Hoping the latest feeding will correct that as it is released into the soil. The potassium was adequate but definitely not high.

In any case being that there's no potassium abundance and the pH is okay, I guess it's perhaps just a straight calcium deficiency. I've been adding it though via the doctor Earth and Cal mag. I guess the best course of action is to just use watchful waiting for now and hope it works itself out. Might add very low doses of Cal mag every other day for next week and watch it, but definitely want to cut it off at minimum a week before the perceived end.
 
Cboat38

Cboat38

Well-Known Member
Whoah! You put 10 tbs of flower girl during feeding? But the directions say 1/4 cup every five gallons which adds up to only 4 tbs so that might be your problem there to many nutrients breaking down over fertilizeing your soil.
 
C

Cheesed_Jay

Member
Cboat38 said:
Whoah! You put 10 tbs of flower girl during feeding? But the directions say 1/4 cup every five gallons which adds up to only 4 tbs so that might be your problem there to many nutrients breaking down over fertilizeing your soil.
Click to expand...
You're right! But I was using the stealth grow formula two tablespoons per gallon and I have a 5 gallon pot. Two tablespoons per gallon every 3 weeks what he says like 50 times in his videos. But maybe you're right maybe that's way too much. I'm definitely not adding anymore for the rest of the grow.
 
Cboat38

Cboat38

Well-Known Member
Yeah cause I use dr earth plus flower girl and seabird guano and that’s it, now depends on the cultivar if you need to feed more then once in flower I’ve had some I top dressed one time and some every three weeks your plants will let you know remember it’s a weed give her what she needs not what you want
 
C

Cheesed_Jay

Member
Cboat38 said:
Yeah cause I use dr earth plus flower girl and seabird guano and that’s it, now depends on the cultivar if you need to feed more then once in flower I’ve had some I top dressed one time and some every three weeks your plants will let you know remember it’s a weed give her what she needs not what you want
Click to expand...
This is my first grow so I was just doing it exactly per the instructions. But you know, before I fed it last, I wondered if she was really hungry. Before I fed it the second time in flower she definitely was showing potassium hunger. Then it stopped after I fed it. This time I feel like it just hasten the black spread, that was already happening though. It wasn't really showing hunger other than this issue. Plus it looks like it's finishing up faster than I expected as well. Heading towards week 8 and it might be done soon. I was expecting 9 or 10 weeks per what I read about the strain. This is where my inexperience shows I didn't realize it was so close to being done. Got to learn though. I wish I wouldn't have fed it at all again, but what's done is done and I really want to try to avoid a huge flushing. I think it might be done any day or most a week from now.
Organic is tricky because you got to really think ahead too. Some nutrients disperses quickly while others slow releases over the course of the whole grow.
 
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