The Grow Awards 2026 🏆 
Dark spots on leaves, developing fast.
dzdr2023started grow question 5y ago
What is this guy's?
It is tenth week of life of this plant.
Please help.
Open
Leaves. Color - Dark-brown
likes
Answer
Homestickycannabisanswered grow question 5y ago
Hey there dzdr. IMHO it's call mag def and if not checked it will destroy a plant. Its something I deal with every grow. Partly due to using R.O water and not providing calcium and magnesium which is filtered out . Also could be caused by pH imbalance leading to lock out. The good thing about cal-mag supolements is it's hard to over do it. Also check out the stems of the leaves and smaller branches if purple or violet color are showing it's a sign of cal mag def. Hopeful this will help my friend.
CHEERS!!!
likes
Complain
Similar Grow Questions
Solved
Werim
3th week of Veg. Nuts deficiency or burn? Might it be a root zone issue?Hi. It's 2x reg fem Royal Runtz and 2x reg fem Special Queen #1 from RQS im using CannaAQUA nutrients + Cannazyme and Rhizo. PH is 5.6 EC 1.3-1.35 water temp 23°C on DWC system. Air temp 27.5°C hum.50%-60%.Light is from MarsHydro series FC-E 6500 730W on 80% and 1m above ladies.Leaves. Tips - Burnt
Leaves. Curl up
Leaves. Color - Dark-brown
4y ago
4
5
Solved
MicroNighthawk
Maui Waui CA deficiency?Can anyone confirm or guess at the kind of deficiency my plant is having?
I am not sure if "hard water" (instead of RO so far) is the right answer or if I need some special sauce...
Thank you!
Details here: https://growdiaries.com/diaries/139533-grow-journal-by-fejg87fb2skvfWeek 9
Leaves. Color - Dark-brown
4y ago
2
3
Solved
illyrian
K deficiency or excess?What do you think of this leaf? Week 10 critical punch autoLeaves. Edges burnt
Leaves. Color - Dark-brown
5y ago
3
3
Solved
Org_grow
Nutrition or something else?Does anyone recognize this brownish leave/vein coloring?
I have searched alot, but could not find anything that looks like this.
It started in the veins a few days ago. But now it's spreading throughout the whole leave.
Also the leaves are very pale. Hat some overwatering oopsiLeaves. Color - Dark-brown
2y ago
2
Solved
N1xon
Why do I have brown/black spots on my OG leaves?Bare with me please. I purchased "aPotforaPot" kind of on a whim late one night. I planted 3 weeks ago yesterday and have been feeding exclusively water with PH ~5.5. Just received Cal-Mag in the mail and plan to use on the next watering. I'm starting to notice spots on OG leavesLeaves. Color - Dark-brown
5y ago
1
2
Solved
bongriplarry
Brown spots, serrated edges curling up - calcium deficiency?This is a Barney's Critical Kush auto that's at about day 57. She's into flowering, but I've just started to notice some brown spots on leaves with some slight tip browning, and the serrated edges on the leaf are curling up.
Is this just a straight calcium deficiency?Leaves. Curl up
Leaves. Color - Dark-brown
5y ago
1
3
Solved
MazzeoN
help, I don't know what's wrongGoodnight! Does anyone know what could be happening to this plant? at first only the lower leaves were affected, but now all the new shoots are affected little by littleBuds. Other
Leaves. Color - Dark-brown
Plant. Other
3y ago
1
2
Solved
T3rMiNaToR3
I water with 50% distilled and 50% rain OR 50% distilled and 50% tap. I have fed once with Grow Big and it happened right after. Might have rubbed nozzle on the underside of the leaves. I water every 2-3 days and water until drop of runoff appears in tray. How much runoff?Week 3
Leaves. Color - Dark-brown
5y ago
6
5
Solved
AvoidantGrower
Burnt? PH lock-out? too much Cal-mag??What do you think is wrong with this plant?
All the other plants surrounding her are fine so I'm not sure what went wrong with this one. I thought it was cal-mag deficiency at first so I doubled cal-mag when feeding but it only proceeded to get worse. The buds look fine tho 👍😳4y ago
2
5
Solved
IQuSX
Коричневый ствол и красные пятна Strain: NoNameОбнаружил очень странный ствол у растения, что с ним?
Был пересажен 5 недель назад из земли в кокос+перлит, при этом было удалено 80-90% предыдущей земли.Leaves. Too few
Leaves. Color - Red or pink
Leaves. Color - Dark-brown
2y ago
1
Solved
m1kax
leaves brown stainsis my 1st time growing weed.
my plants start get this brown stains on top leaves 2 weeks ago;
i check ph was 5.95; so i think this could be calcium, because internet say they cant absorb calcium;
i have high humidity before the stains appear like 80% but was only 4 or 5 days.Leaves. Color - Yellow
Leaves. Color - Dark-brown
Leaves. Color - Black or grey
2y ago
2
4
Solved
Magic43562
Brown spotsBrown spots only on 1 leaf, is this a problem? Wasn’t there this morningLeaves. Color - Dark-brown
5y ago
4
3
Solved
MedicineMaker
Calcium Deficiency?Any ideas on what this could be? Water 90% RO with 10% well water 110PPM, PH 6.0-6.5, Autoflower, Day 29 of grow, Fox Farm Ocean Forest, No nutes added yet as I heard FFOF was hot for autos, plan on nutes at preflower, 20/4 schedule w/240LED 100% at 90CM, DLI 40.Leaves. Color - Dark-brown
3y ago
2
2
Solved
420loss
Bronze spotsWhat could be this spots? Found 4.Week 7
Leaves. Color - Dark-brown
3y ago
18
9