Yellow leaves edges/tips, curling upward

[Daylight]

10 days ago this plant had only yellow tip leaves, no tips were brown, a few minor curling nothing to worry about, about 20% leaves had yellow edges (not just tips). i looked up charts/internet and concluded nitrogen deficiency. i gave it:

24th=2tbs of Pridesland Grow granular 6 3 3.5 (not soluble but does have a % powder for quick uptake they told me) in 8gal water.
26th 1oz Seedlinger 3-0.6-0.6 liquid, 3tsp Kelp, 1/6 tsp Ca (all soluble) in 8gal water.
29th 1.7oz liquid bloom 2 5 0, 3tsp kelp (.5 0 12) in 8gal water.
31st - 2oz earthworms powder scratched in (.5 0 0) "will not burn").
soil is costco miracle grow organic (it's 3rd year i've tried this in one plant, i don't think it's any good)

in the last 4 days it's really starting to flower. it's been hot, sunny all day, the soil felt dry, i don't suspect over watering, the meter i have does work it's just 4" probe but works cause when i water i test and meter shows blue (wet) then next day it doesn't read anything, red (dry). 4 weeks ago added 8 cups of fish compost. the fertilizer directions packaging, i'm doing less than half than the fert packaging direcdtions.

note some tips r now turning brown. and more leaves curling up so not sure what's going on?

thanks for any tips!

 

[Captspaulding]

The curling leaves going upwards like that with tips that are burnt going upwards like that are generally indicators of heat stress
But some of this looks to be genetic in my opinion, in terms of the leaf curl.
So I’d say give it some more nitrogen and try watering early early am.

 

[MJmadscientist]

Well idk about your conditions but I’d say she’s definitely getting a little hot.
The soils mix you stated is a poor choice for cannabis but I’ve made lemonade from lemons in the past. It works but there is better available.

Ditch the miracle gro next time.
Look for my post on my mix and it’s easy to make. There are also plenty of good soils that are for sale like promix. If not using get some fabric pots.

Is this new or old miracle grow? Any miracle gro has some type of time release feeding and it’s gonna mess with your nute game.

Has it had any iron/cal-mag? More so on the mag and iron?
Do you think it could be heating the roots up and drying out quicker than you think?


Just throwing those out there. I’ve had them dry out on me and get the nutes to water too high causing a problem.
Mixes with a lot of pear can also be somewhat hydrophobic.

I’d be easy on the nitrogen but she could use some with plenty of water. Maybe a quick source like some calcium nitrate.
Actual sea-k you can go pretty heavy on. Especially starting to flower you boost the soil microbes with food and it’s full of nutrients and hormones that make her come alive!
Sea-k also will help with some of the heat stress and tolerances.

If you can get some a good humic and fulvic acid mix in the water can really boost a plant as well. It ups the processing of nitrogen so be careful it can burn em or grow em up with spare nutes in the soil.


Try taking us a photo first thing in the morning and let’s see how she’s looking. Usually they are much perkier in the morning when temps are lower and humidity is higher.

 

[carlosescobar]

ive done this twice now , its over fed, the soil already has nutrients in and then you have added allsorts of things which are not really needed . i had one grow in rich soil , added bit too much silica, top dressed with guano and added 2ml of PK 14/15 in a watering and it locked up almost overnight . what made it worse was that i mistook it for led heat burning so moved it away from the light and gave another feed.
then this year i forgot i had switched over to soil from coco and fed this plant over 3 waterings , ( just 2ml of tomato type feed ) it started curling , which i see now as a warning sign . i dont know at what point they lock up but they just stop, best thing to do is water with low ph water only . ive never actually had one recover , they were both near to harvest so i chopped them.

 

[Daylight]

Well idk about your conditions but I’d say she’s definitely getting a little hot.

Try taking us a photo first thing in the morning and let’s see how she’s looking. Usually they are much perkier in the morning when temps are lower and humidity is higher.

and Captspaulding and carlosescobar
1. i don't think it's heat, been only 80s highs for a few hours. past 8 years had weeks of 90s 100s entire day and this strain/all strains i never seen issue. it appears they love the extreme heat.
2. i found 2022 pics of this same batch/strain BlackJack and no cupping, no yellow edges about this exact time in flowering.
3. 4 weeks ago this plant leaves were shiny green which i've had over the years in several strains of plants shiny green which i thought was too much nutrients i added. this year 2025 BJ i've added nothing from planting outdoor june 1, only water. the shinny green leaves was a sign to me this Miracle-Gro® Organic Choice® Raised Bed & In-Ground Soil with Compost was too hot in something. it wasn't until last 7 days seeing the yellow did i add nutrients listed above.
4. i've always used fabric pots. this year i've about doubled the water. years past i'd give 5gal every 2 days,. every day if high 80s 90s 100s every day. 2025 i'm giving 10 to 15 gallons sometimes everyday, usually every 2 days. and we haven't had constant 90s yet this year. all the stores were out of the 8" single probe moisture meter. a THCfarmer in another post suggested poking the probe through the fabric to sample the bottom of the pot too which i never thought of. (do you read reviews on products? lowes, HD, most items have 10 to 30% 1 Star reviews, verified buyers, many with pictures stating the time doesn't work, broke in days/weeks... that's what i saw with the moisture and ph meters.
5. for 8 years i can see when my plants are dry, the leaves look healthy upwards, then leaves droop, i add water and in 1 hour the plant looks normal. (that might be too much stress for the plant? i don't do this on purpose it's just a signal i noticed.)
6. i have a container of liquid humic 8 years old, is it still okay to use?
7. new Miracle-Gro® Organic Choice® Raised Bed & In-Ground Soil. it's so cheap at costco $9 on sale compared to $14 to $30 others. but it's not worth the issues. Pridesland told me not to use it, root rot down the line. but i've used it for 5 years with semi okay results.
8. i haven't added nutrients until last days listed above. so CaMg is missing. i did add minor amout of soluable Ca, 1/6 tsp to 8 gal water.
9. carlosescobar over the years i've also over nuntrients but i'm not sure if i've ever locked a plant. it seems to me i've given high side to burn tips but the plants got huge and still flowered. (see last image)

do you think the Impact Organics Earthworm Castings or the SeaCoast Compost right now? or go with liquid CaMg now? or the liquid Bloom 2 5 0
aug 3 morning, sun filtered in clouds. no change in plant look. more tips are changing from yellow to tan.

 

[Daylight]

2022 same patch same strain about same time in growth. i can't remember which soil i used, the miricle grow or my recycled pile of 8 years of higher quality bag soil reclaimed. leave in a pile for 2-4 years then reuse. the ladder picture is about 2021. i've scaled back. note in the ladder pic you can see bright shiny day green leaves and brown tip leaves. i used to give weekly high quality liquid Grow then Bloom, look at the size. i used Vital Earth products but 5 years ago they went out of business.

 

[davethcman]

and Captspaulding and carlosescobar
1. i don't think it's heat, been only 80s highs for a few hours. past 8 years had weeks of 90s 100s entire day and this strain/all strains i never seen issue. it appears they love the extreme heat.
2. i found 2022 pics of this same batch/strain BlackJack and no cupping, no yellow edges about this exact time in flowering.
3. 4 weeks ago this plant leaves were shiny green which i've had over the years in several strains of plants shiny green which i thought was too much nutrients i added. this year 2025 BJ i've added nothing from planting outdoor june 1, only water. the shinny green leaves was a sign to me this Miracle-Gro® Organic Choice® Raised Bed & In-Ground Soil with Compost was too hot in something. it wasn't until last 7 days seeing the yellow did i add nutrients listed above.
4. i've always used fabric pots. this year i've about doubled the water. years past i'd give 5gal every 2 days,. every day if high 80s 90s 100s every day. 2025 i'm giving 10 to 15 gallons sometimes everyday, usually every 2 days. and we haven't had constant 90s yet this year. all the stores were out of the 8" single probe moisture meter. a THCfarmer in another post suggested poking the probe through the fabric to sample the bottom of the pot too which i never thought of. (do you read reviews on products? lowes, HD, most items have 10 to 30% 1 Star reviews, verified buyers, many with pictures stating the time doesn't work, broke in days/weeks... that's what i saw with the moisture and ph meters.
5. for 8 years i can see when my plants are dry, the leaves look healthy upwards, then leaves droop, i add water and in 1 hour the plant looks normal. (that might be too much stress for the plant? i don't do this on purpose it's just a signal i noticed.)
6. i have a container of liquid humic 8 years old, is it still okay to use?
7. new Miracle-Gro® Organic Choice® Raised Bed & In-Ground Soil. it's so cheap at costco $9 on sale compared to $14 to $30 others. but it's not worth the issues. Pridesland told me not to use it, root rot down the line. but i've used it for 5 years with semi okay results.
8. i haven't added nutrients until last days listed above. so CaMg is missing. i did add minor amout of soluable Ca, 1/6 tsp to 8 gal water.
9. carlosescobar over the years i've also over nuntrients but i'm not sure if i've ever locked a plant. it seems to me i've given high side to burn tips but the plants got huge and still flowered. (see last image)

do you think the Impact Organics Earthworm Castings or the SeaCoast Compost right now? or go with liquid CaMg now? or the liquid Bloom 2 5 0
aug 3 morning, sun filtered in clouds. no change in plant look. more tips are changing from yellow to tan.

That looks like russet mites to me u need a handheld microscope to see em they look like little see through slugs with a bunch of legs you will know when hairs start poppin and they are mostly red already not white hairs by then good luck it's almost to late but there's a product called grow safe that kicks their asses

 

[MJmadscientist]

and Captspaulding and carlosescobar
1. i don't think it's heat, been only 80s highs for a few hours. past 8 years had weeks of 90s 100s entire day and this strain/all strains i never seen issue. it appears they love the extreme heat.
2. i found 2022 pics of this same batch/strain BlackJack and no cupping, no yellow edges about this exact time in flowering.
3. 4 weeks ago this plant leaves were shiny green which i've had over the years in several strains of plants shiny green which i thought was too much nutrients i added. this year 2025 BJ i've added nothing from planting outdoor june 1, only water. the shinny green leaves was a sign to me this Miracle-Gro® Organic Choice® Raised Bed & In-Ground Soil with Compost was too hot in something. it wasn't until last 7 days seeing the yellow did i add nutrients listed above.
4. i've always used fabric pots. this year i've about doubled the water. years past i'd give 5gal every 2 days,. every day if high 80s 90s 100s every day. 2025 i'm giving 10 to 15 gallons sometimes everyday, usually every 2 days. and we haven't had constant 90s yet this year. all the stores were out of the 8" single probe moisture meter. a THCfarmer in another post suggested poking the probe through the fabric to sample the bottom of the pot too which i never thought of. (do you read reviews on products? lowes, HD, most items have 10 to 30% 1 Star reviews, verified buyers, many with pictures stating the time doesn't work, broke in days/weeks... that's what i saw with the moisture and ph meters.
5. for 8 years i can see when my plants are dry, the leaves look healthy upwards, then leaves droop, i add water and in 1 hour the plant looks normal. (that might be too much stress for the plant? i don't do this on purpose it's just a signal i noticed.)
6. i have a container of liquid humic 8 years old, is it still okay to use?
7. new Miracle-Gro® Organic Choice® Raised Bed & In-Ground Soil. it's so cheap at costco $9 on sale compared to $14 to $30 others. but it's not worth the issues. Pridesland told me not to use it, root rot down the line. but i've used it for 5 years with semi okay results.
8. i haven't added nutrients until last days listed above. so CaMg is missing. i did add minor amout of soluable Ca, 1/6 tsp to 8 gal water.
9. carlosescobar over the years i've also over nuntrients but i'm not sure if i've ever locked a plant. it seems to me i've given high side to burn tips but the plants got huge and still flowered. (see last image)

do you think the Impact Organics Earthworm Castings or the SeaCoast Compost right now? or go with liquid CaMg now? or the liquid Bloom 2 5 0
aug 3 morning, sun filtered in clouds. no change in plant look. more tips are changing from yellow to tan.

The more I look I don’t think you burned them at all. That looks a lot like a potassium deficiency. The tiny tips dried up correct? You can still add a little calmag. If needed more mag epsom salt is also good but my nutes are already high in Mag and calcium so i don’t use it on my cannabis.

Could she be needing more potassium from her size and the fact flower is starting too?
If you are dealing with potassium- leaf edges yellow and they cup like yours but worse as it progresses.
CalMag will be fine to add especially starting flower.
I’d be looking at some soluble sea-K greenleaf nutrients has one I’ve been liking a lot and it won’t contribute to any burning but will add some of the K you need.
Do you have any potassium silicate? That might be the ticket with some of that kelp to turn her around. Plus some silica is always good for the plant.

As far as nitrogen you’ll always be using some even in flower. The color of her as a whole says she may need a very small amount with the above and WAIT to see if she darkens up after the K deficiency is resolved.
That could contribute to some of the yellow.

 

[MJmadscientist]

This is a far along potassium deficiency but a reference to show the similarities and direction it could be going.

I zoomed in on the lear showing less damage to show the edges and the cupping like a hotdog.

 

[Daylight]

That looks like russet mites to me u need a handheld microscope

i did a not thorough inspection weeks ago looks clean. i do have the pc microscope and will check leaves today. i maintenance spray with Lost Coast Plant Therapy. i've never had an infestation issue except one season, cannabis aphids extreme infestation. i double the Plant Therapy dose, sprayed nothing. called Plant Therapy, Dirk i believe is the owner and answers every email/call personally, he's a fantastic human being and knowledgeable. i added 1oz of Isopropyl, 10% better. (originally Dirk and local shop mentioned about spraying with garden hose and how tough aphids are. i didn't listen about garden hose thinking of mold...) 4th day spraying, no progress, and beginning flowering, i had nothing to lose so i garden hosed blew aphids off. seemed like 90 gone., sprayed Plant Therapy double dose + 1oz Isopropyl (in 2gal hand pump). next day plant was 95% clean. sprayed again, next day 100% gone and that plant produced perfect. weeks earlier i noticed aphids on my roses, the forming flower outer skin/petal and didn't think of anything. the cannabis aphids definitely migrated from rose to cannabis. so now i spray the roses once a month.

Lost Coast claims applicable for russet mites.

 

[Daylight]

This is a far along potassium deficiency but a reference to show the similarities and direction it could be going.

I zoomed in on the lear showing less damage to show the edges and the cupping like a hotdog.

this looks very similar to exactly my leaves but more advanced. i have a box of granular Down To Earth Langbeinite Kmag 0-0-22. just got an extremely knowlegeable sales person telling me i can put this into 5 gal bucket, agitate, and it will go into solution, mostly. (i've had problems with other DTE granular items trying this and i end up with a bucket of muck on the bottom.)

or

i also have a liquid bottle of FoxFarms CalMag, directions say 1tsp per gal so i'd do 4tsp in 5gal today.

do you know if a liquid fertilizer or a granular fertilzer put into solutions gets to the root system uptake faster? or the same?

 

[MJmadscientist]

this looks very similar to exactly my leaves but more advanced. i have a box of granular Down To Earth Langbeinite Kmag 0-0-22. just got an extremely knowlegeable sales person telling me i can put this into 5 gal bucket, agitate, and it will go into solution, mostly. (i've had problems with other DTE granular items trying this and i end up with a bucket of muck on the bottom.)

or

i also have a liquid bottle of FoxFarms CalMag, directions say 1tsp per gal so i'd do 4tsp in 5gal today.

do you know if a liquid fertilizer or a granular fertilzer put into solutions gets to the root system uptake faster? or the same?

Liquid feeding is always faster if it’s a water soluble fertilizer. You’re shootings for a completely water soluble mix. If your microbe life in the soil is good they go right to work breaking it down.

Not saying you got to change up. The plant is nice. However I’ve had a lot of luck with the 2 part mega crop. You can tweak it and add on to it. I’ve not had any nutrient issues other than getting it a little hot but I’m honestly mixing it hot on purpose for my environment.

The humic and fulvic acid mix I use is ion-14. Only complaint is the ash never dissolved. They do have a liquid solution now and others have really good silica too that dissolves well. I’m using it because it doesn’t add to my potassium levels or any nkp. The only thing is it will process nitrogen a little faster.
Plants grow really vigorously and stems get fat on this.

I do keep a lot of greenleaf nutrients sea-k on hand and use it through the entire grow. Including foliar sprays till flower is into 4-6wk depending on the maturity of the flowers.

The mega crop is heavy in calcium and magnesium. Plus you add more calcium fast with the cal-nitrate. I use that plus epsome sale with some 0/50/30 Bud charge when I’m really pushing them hard.

With all this said I really push the water to mine and have fabric pots to help with drainage and air pruning the roots. Plus they breathe well. This allows me to push them harder.
During stretch it gets very crazy with the right feed and water routine here. I’m outdoors completely at the mercy of weather though. Very little indoor here. Where I’m at it rains a lot then we get insanely hot and dry so I have to adapt to keep them healthy.

 

[MJmadscientist]

i did a not thorough inspection weeks ago looks clean. i do have the pc microscope and will check leaves today. i maintenance spray with Lost Coast Plant Therapy. i've never had an infestation issue except one season, cannabis aphids extreme infestation. i double the Plant Therapy dose, sprayed nothing. called Plant Therapy, Dirk i believe is the owner and answers every email/call personally, he's a fantastic human being and knowledgeable. i added 1oz of Isopropyl, 10% better. (originally Dirk and local shop mentioned about spraying with garden hose and how tough aphids are. i didn't listen about garden hose thinking of mold...) 4th day spraying, no progress, and beginning flowering, i had nothing to lose so i garden hosed blew aphids off. seemed like 90 gone., sprayed Plant Therapy double dose + 1oz Isopropyl (in 2gal hand pump). next day plant was 95% clean. sprayed again, next day 100% gone and that plant produced perfect. weeks earlier i noticed aphids on my roses, the forming flower outer skin/petal and didn't think of anything. the cannabis aphids definitely migrated from rose to cannabis. so now i spray the roses once a month.

Lost Coast claims applicable for russet mites.

Not that I would recommend in a later flower situation. It could affect the taste if too late into flower but we are talking very close to harvest. You also HAVE to spray at NIGHT. Temps need to be lower but I use NeemMax for emergencies and helps with fungi as well.


The spinosad bacteria spray is quite effective in my experience against a lot of our bugs we fight every year. It’s all organic labeled as well.

 

[Daylight]

the plant with curling leaves i don't see any type of insect. i purchased this #1 rated on amazon like $20 6 years ago, had thousands of excellent reviews. i haven't used it for 3 years. just pulled out, it works fine but the material is breaking down. the outer whatever it is is tacky/sticky like tape. the material shell is oxidizing breaking down. i noticed years ago i cannot post product reviews because i don't purchase enough items. https://www.amazon.com/jiusion-magnification-endoscope-microscope-compatible/dp/B06WD843ZM?th=1

 

[Daylight]

The more I look I don’t think you burned them at all. That looks a lot like a potassium deficiency.

you were correct. i solutioned some Langbeinite 0-0-22 and this plant/leaves quickly improved to normal in 3-4 days. THANKS! then we went on vacation and had the neighbors take care of our plants. the extreme heat/sun doesn't seem to harm the weed but the heat/sun destroys the fruit. the sun side of the fruit (apples, pears) looks like burnt with a torch. it's a lot of work/money gone up in smoke.