Burning tips even though I have been very careful with nutrients?

Markyb · Mar 6, 2025

Hi!
I'm seeing lots of leaves getting their tips burned. I have been very stingy with the nutrients.
The feed has only been around EC 0.6 (my tap water is 0.1) and I still get burning tips, but on the other hand I see lots of signs of deficiencies.

I have also always kept the pH level on water (with and without nutrients) at 6.6. (Im growing in soil)
The plant is 56 days old now.

Please can you guys help me out, what's going on?

Galgrows · Mar 6, 2025

No big deal in my opinion your plants look great. And your over the biggest hurdle and cruz'in to the finish line with a healthy grow. Many growers get tiny burnt tips even the pros so you got nothing to worry about.

Markyb · Mar 6, 2025

Galgrows said:
No big deal in my opinion your plants look great. And your over the biggest hurdle and cruz'in to the finish line with a healthy grow. Many growers get tiny burnt tips even the pros so you got nothing to worry about.

Thanks! It's a very stressful time. I'm guessing it's still two..three? weeks to go before she is ready.
I really don't want to mess things up this close to finish line.

The affected leaves are fanleaves, not all of them of course but I mean there a are no burnt tips on sugar leaves.
Have I understood correctly that at this phase the fanleaves serve little to no purpose, other than being a nutrient reserve for mobile nutrients? And the sugar leaves are doing all/most of the photosynthesis?

GNick55 · Mar 6, 2025

yes it needs its fan leaves and try to keep the plant green..
i’d say there’s like 5 or so weeks to go..

phxazcraig · Mar 6, 2025

I've always had tip burn, and I try to use the GH nutes standard mix, diluted slightly. I'm growing in coco now, at pH 6.0.

This latest crop showed no tip burn at all, until I got the the early flower stage. Probably due to my increasing the nute strength up to 850ppm. (Was around 500).

I may dilute further, but in the past some tip burn has never seemed to hurt anything, at least not in a major way.

LoveGrowingIt · Mar 7, 2025

A high VPD can cause tip chlorosis followed by necrosis.

Markyb · Mar 7, 2025

LoveGrowingIt said:
A high VPD can cause tip chlorosis followed by necrosis.

Hi,
My VPD during flower has been between 1.15 - 1.22

I struggle getting the tent temp below 25C. All I could do is to decrease VPD is to increase humidity which is already at 50%. Is it safe?

I do have a fan blowing inside the tent 24/7 and the inline fan to recycle the tent air. The lung room is also ventilated so there is plenty of fresh air available.

Markyb · Mar 7, 2025

GNick55 said:
yes it needs its fan leaves and try to keep the plant green..
i’d say there’s like 5 or so weeks to go..

Thanks! The problem is that I don't know how to keep it green. It keeps getting more and more yellow and then getting burned even at miniscule nutrient doses.

Markyb · Mar 7, 2025

phxazcraig said:
I've always had tip burn, and I try to use the GH nutes standard mix, diluted slightly. I'm growing in coco now, at pH 6.0.

This latest crop showed no tip burn at all, until I got the the early flower stage. Probably due to my increasing the nute strength up to 850ppm. (Was around 500).

I may dilute further, but in the past some tip burn has never seemed to hurt anything, at least not in a major way.

Thanks! My EC when feeding has been 0.6 max, i get nutrient deficiency symptoms and nutrient burn symptoms at the same time. I'm totally loss on what I should be doing.

Choppr · Mar 7, 2025

mild tip burn is nothing to worry about, In this pic look at the margins (serrated edges) are pointed up- this indicates shes getting a little too hot, her color is light green indicating a mild lack of nitrogen,(shes moving nitrogen now from her bottom leaves) she needs a little more, not too much as she's in flower so dont jump the fence, you said "the Plant is 56 days old" so Im assuming shes an Auto flower, so she'll probably go 80+ days, although Ive had them go a 100+ days...she's in pretty good shape, with a few correctable issues.

Your EC seems a little low, Auto's are light feeders, but my autos in flower are around 600-700ppm (Ec 1.2-1.4) so I would raise your Light height or lower power (76-78 degrees at the canopy) and raise your feed incrementally, try 400ppm/.8ec to start with.( if they're ok with that 8-10 days maybe a little more?)

Remember as a cultivator, Leaf "Color & Silhouette", is our Plants talking to Us, after a few grows your eyes will learn to see even the slightest changes in "shades of green". Color tells Us how to mix our next feed. Her leaf silhouette looks fine other than the margins as noted...

and Yes you need your fan leaves especially nearest the fruits.

Right On!

Markyb · Mar 7, 2025

Choppr said:
mild tip burn is nothing to worry about, In this pic look at the margins (serrated edges) are pointed up- this indicates shes getting a little too hot, her color is light green indicating a mild lack of nitrogen,(shes moving nitrogen now from her bottom leaves) she needs a little more, not too much as she's in flower so dont jump the fence, you said "the Plant is 56 days old" so Im assuming shes an Auto flower, so she'll probably go 80+ days, although Ive had them go a 100+ days...she's in pretty good shape, with a few correctable issues.

Your EC seems a little low, Auto's are light feeders, but my autos in flower are around 600-700ppm (Ec 1.2-1.4) so I would raise your Light height or lower power (76-78 degrees at the canopy) and raise your feed incrementally, try 400ppm/.8ec to start with.( if they're ok with that 8-10 days maybe a little more?)

Remember as a cultivator, Leaf "Color & Silhouette", is our Plants talking to Us, after a few grows your eyes will learn to see even the slightest changes in "shades of green". Color tells Us how to mix our next feed. Her leaf silhouette looks fine other than the margins as noted...

and Yes you need your fan leaves especially nearest the fruits.

Right On!

Thanks! I'll try to get the temps down. Currently she is been sitting with 25C in the tent. Trying to get the temps down to 24C next.

I have been really stingy with the nutrients so the lack of nitrogen does come as a surprise. I'm assuming I should not add
any Veg nutrients but adjust the bloom nutirient a little bit higher?
The bloom nutrient I have been using (Canna Terra Flores) has surprisingly high amount of nitrogen, its NPK is 2-2-4

Today I have a plain water for her, as I fed her with last watering two days ago. I'm assuming I should stick to plain water between feedings?
Though I do get runoff even when I water her with nutrient water, does that also flush out the old salts?

Thanks again!

Choppr · Mar 7, 2025

@Markyb - I wont get into the weeds(pun intended) and give advice on watering habits in soil I left soil many years ago for Hydro. I will say keep doing what's working, and yes a sip of plain water doesn't hurt when they need, as your soil has nutrients. With Auto's (short run 90-110 day Plants) and your weaker feeds I wont worry too much about salts, your Plants dont show indications of high salts. (leaves will show spotting) Just dont water heavy pots, give them plenty of dry-back, or you'll get into trouble, the trouble will be lack of Oxygen in the Rhizome...its all about the Oxygen!

Markyb · Mar 7, 2025

Choppr said:
@Markyb - I wont get into the weeds(pun intended) and give advice on watering habits in soil I left soil many years ago for Hydro. I will say keep doing what's working, and yes a sip of plain water doesn't hurt when they need, as your soil has nutrients. With Auto's (short run 90-110 day Plants) and your weaker feeds I wont worry too much about salts, your Plants dont show indications of high salts. (leaves will show spotting) Just dont water heavy pots, give them plenty of dry-back, or you'll get into trouble, the trouble will be lack of Oxygen in the Rhizome...its all about the Oxygen!

Thanks!
There's not much nutrients left in the soil, its Biobizz Lightmix which is meant mostly for growing seedlings I think. It was recommended by many growers because its not too hot to begin with.

I have been watering by weight. I measured the pot when I filled with the soil, and I water her when it gets close to that dry weight. So far I think she has not been overwatered once, at least she has not shown any overwatering symptoms.

Oldchucky · Mar 7, 2025

There are used to be an old, saying, if your tips aren’t burnt, you’re not trying hard enough!

OurGas · Mar 7, 2025

NPK doesn't burn plants. Magnesium will. Manganese will. Boron will. You fix those problems by adding every other nutrient to match the over abundant nute.

Almost everything pot growers believe is backwards. Nute burn should be viewed as a deficiency, always. Unless your pH is low or you add Epsom salts because some asshole on the internet decided to fuck with you.

LoveGrowingIt · Mar 7, 2025

Markyb said:
My VPD during flower has been between 1.15 - 1.22

In my growing experience, I've observed that when the VPD rises above 1.2, tip burn becomes more likely.

Markyb said:
I struggle getting the tent temp below 25C.

25C (77F) is the target temperature I use.

Markyb said:
All I could do is to decrease VPD is to increase humidity which is already at 50%. Is it safe?

Humidity below 60% is usually considered safe. I run mine in the mid-50s after plants are past the establishment stage.

Markyb · Mar 7, 2025

OurGas said:
NPK doesn't burn plants. Magnesium will. Manganese will. Boron will. You fix those problems by adding every other nutrient to match the over abundant nute.

Almost everything pot growers believe is backwards. Nute burn should be viewed as a deficiency, always. Unless your pH is low or you add Epsom salts because some asshole on the internet decided to fuck with you.

Hi! Interesting point! From what book is that illustration from? I would like to read more.
Actually someone suggested adding epsom salts to the feed to correct Mag deficiency.. I did NOT add the salts..

TheGoldenRoad · Mar 7, 2025

Oldchucky said:
There are used to be an old, saying, if your tips aren’t burnt, you’re not trying hard enough!

I live by this No tips escape a good scorching

TheGoldenRoad · Mar 7, 2025

Markyb said:
I did NOT add the salts..

Good. Salts do have their place but it’s not here.

LoveGrowingIt · Mar 7, 2025

OurGas said:
NPK doesn't burn plants. Magnesium will. Manganese will. Boron will. You fix those problems by adding every other nutrient to match the over abundant nute.
...
Almost everything pot growers believe is backwards. Nute burn should be viewed as a deficiency, always. Unless your pH is low or you add Epsom salts because some asshole on the internet decided to fuck with you.

That's an interesting perspective on nutrients, some of which I haven't seen before.

Burning tips even though I have been very careful with nutrients?

Burning tips even though I have been very careful with nutrients?

Markyb

Galgrows

Markyb

GNick55

phxazcraig

LoveGrowingIt

Markyb

Markyb

Markyb

Choppr

Markyb

Choppr

Markyb

Oldchucky

OurGas

LoveGrowingIt

Markyb

TheGoldenRoad

If the bus comes by, get on ✌️

TheGoldenRoad

If the bus comes by, get on ✌️

LoveGrowingIt

Burning tips even though I have been very careful with nutrients?

Burning tips even though I have been very careful with nutrients?

Markyb

Galgrows

Markyb

GNick55

phxazcraig

LoveGrowingIt

Markyb

Markyb

Markyb

Choppr

Markyb

Choppr

Markyb

Oldchucky

OurGas

LoveGrowingIt

Markyb

TheGoldenRoad

If the bus comes by, get on ✌️

TheGoldenRoad

If the bus comes by, get on ✌️

LoveGrowingIt

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