Overnight Decline - What the ****?

Plants are White Widow autos. Approx. 2-3 weeks old growing indoors under CFLs. Just started feeding with 1/2 strength FF Grow Big with a little calmag. Plant was looking great then all of a sudden it looks very sick, like overnight… Growing in Happy Frog soil. Watered at 6.5ph. Leaves are as they appear in the photos and are very dry and brittle. Hope someone has some insight as to the problem.
Thanks in advance, EE

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looks like over watering to me, without knowing all the details.


Thanks for the suggestion but I don’t think so. Plant was doing fine with regular watering and drying before rewatering. I have another that has been treated the same way and it is not exhibiting any distress. Soil looks quite wet now because when I saw this problem I thought it was a nute problem so I thoroughly flushed with plain phed water and it’s still drying out. When flushed, the runoff was in the 5.5 range (?) so I did flush with higher ph to try to raise soil level.

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You said it, that’s the issue. Just monitor new growth and runoff

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Better re-check your numbers: that’s SEVERE nute burn. Either your PH meter is way off or the nutrients given were FAR in excess of what was called for.

I am sorry to say with autos you are better off starting over. They will never amount to much now.

@MattyBear @dbrn32 @blackthumbbetty @Bogleg whaddaya think?


Thanks Sick. Don’t know how it got so low. always watered at ph 6.5 after nutes added. I’'l keep an eye on it and see if it improves.


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Thanks Myfriend. Don’t think it’s the meter as recently purchased and properly calibrated according to directions with included calibrating powders. Will recheck nute calculations. Mixing at half strength according to FF feeding guide. Oh well, if it doesn’t improve, I’ve got a couple extra seeds and I’ll start over.

Thanks, EE


This sort of stuff happens. Sucks when it happens to you though.

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Good possibility. It’s hard to tell with condition of plants, but I thought I seen a few wilted pistils in there. If that’s the case I would agree they won’t amount to much.


Don’t think it’s showing any pistils yet, only 2 weeks old. I’ll agree that it’s probably shot. Can’t believe I screwed it up. This is not my fist load of taters:stuck_out_tongue_winking_eye: Always had pretty good luck with autos. Just wanted a quick turn around. We’ll see what happens.

Thanks, EE


Yeah, she’s definitely showing pistils. I’d save yourself the time and heartache and start over. If they are able to recover (those leaves will never turn green again), you probably won’t get more than an ⅛ of larfy buds from each of them.

Such rotten luck. Probably your pH. Maybe coupled with a too heavy feeding. What kind of lights are you using? How big are your pots? What kind of water are you using? What are you using to adjust your pH? What are your temps and relative humidity?


Why are your leaves so wet? What are you spraying them with and how often? I thought I saw pistils, but maybe it’s just reflection from the water drops?


I don’t see any pistils myself. I see some leaf tips that are curling up and dry that look like pistils, kinda. I have the same question as Betty, though.

I don’t grow in soil, but typically when I add nutes to water the PH goes down - I would expect if soil is overloaded with salts, the PH in it might come out low on a run-off test?


Your plant seems to be suffering fron

Nitrogen Toxicty … Here are a couple of pic’s showing just that
And the fix will be posted just be;low the pic’s




Nitrogen Toxicity

Nitrogen toxicity - too much nitrogen - Cannabis growing problem: Dark green leaves,
shiny leaves, clawing, weak stems, and overall slow growth. Marijuana leaves that are nitrogen
toxic often get “The Claw” or talon-like leaves that are bent at the ends. They also do an odd
curving (or cupping) that is often mistaken for overwatering, but is unique to nitrogen toxicity.
You can see a “clawing” leaf pictured to the right and more pictures below (click each picture
for a close-up).

Leaves that turn into claws often start turning yellow and dying if the nitrogen toxicity
is not treated, much like a nitrogen deficiency, only the leaves will continue to get more
and more clawed. Leaves eventually turn yellow or brown and fall off. You can tell if
yellowing is caused by too much nitrogen because the rest of the plant will be dark green,
and the yellowing leaves will turn into claws first.

The majority of times that growers encounter problems with nitrogen, it’s from giving too
much of it to their plants.

Many new growers accidentally give their plants give too much Nitrogen, especially in the
flowering stage. This results in dark, shiny, clawing leaves.

A Nitrogen toxicity can also cause certain leaves to turn yellow, but other than that it
looks nothing like a cannabis nitrogen deficiency?

Your plant needs a lot of nitrogen in the vegetative stage, and it’s generally hard to
give too much as long as you’re not going completely overboard with nutrients. Nitrogen
is a big part of what makes leaves green, and is incredibly important to the process of
photosynthesis (making energy from light).

But cannabis plants need relatively low levels of Nitrogen in the second half of the
flowering/budding stage. While your plants still need N (nitrogen) during flowering,
too much N at this stage will prevent your plants from forming buds properly, resulting
in lower yields, less potency and possibly inferior buds.

This is why it’s important to avoid any type of “time-release” nutrients or soil
(for example, standard Miracle-Gro soil) as they will keep giving your plant a lot
of N even after its started flowering.

When it comes to nitrogen, this is what your plant needs:

Vegetative Stage - higher levels of Nitrogen (pretty much any plant food will do)

Most complete plant foods that you get at a gardening store contain high levels of nitrogen
(N). These nutrient systems tend to work well in the vegetative stage.

Some examples of cannabis-friendly one-part Vegetative nutrient systems…

Dyna-Gro “Foliage Pro”

General Hydroponics “FloraNova Grow”

Pretty much any complete plant food

Flowering Stage - lower levels of Nitrogen (use “Bloom” or Cactus nutrients)

It’s extra important to find a nutrient system with lower levels of nitrogen for the last
part of your plant’s life. Many “Bloom” or “Flowering” style base nutrients are just the ticket.

Some examples of good one-part Flowering nutrient systems…

Dyna-Gro “Bloom”

General Hydroponics “FloraNova Bloom”

If you can’t order online and can’t find a good one-part base Bloom formula locally, you do
have other choices. Though not an ideal choice, most Cactus plant foods will contain good
nutrient ratios for growing cannabis during the budding stage. So in a pinch, you can use
the cactus nutrients that can be found at most gardening stores.

Different strains react differently to nitrogen toxicity. Some plants get dark green leaves
with no clawing. Some strains will get leaves that do the weird 90 degree bend at the tips,
while other strains or individual plants start curling like claws and then turn yellow / brown
and fall off like a deficiency. Yet these are all signs of too much nitrogen.

Signs of Nitrogen Toxicity

This marijuana plants has been fed too much nitrogen Dark green leaves and foliage

Leaf tips may turn down, without signs of overwatering.

You may notice yellowing on the affected leaves or other signs of nutrient deficiencies as
time goes on

Nitrogen toxicity is often but not always accompanied by nutrient burn

The Claw often seems random, affecting leaves here and there

Heat and pH problems will make the clawing worse, as they stress out the plant and lower her
defenses, and cause her to drink more water (and uptake more N)

As time goes on, the claw leaves will eventually start turning yellow, getting spots, and dying

This marijuana plants has been fed too much nitrogen

Too much nitrogen causes marijuana leaves to curl down like talonsDark green leaves are a sign
of nitrogen toxicity


This cannabis seedling is dark because it was underwatered in a “hot” soil mix (too much Nitrogen),
but after watering the plant as normal for a week or two, the plant started growing vigorously

Underwatered in a "hot’ (nutrient rich) starting mix led to this plant developing a nitrogen

Solution: Reduce the Nitrogen your plant is getting!

Reduce the amount of nitrogen that is being fed to the plants. If you are feeding extra
nutrients, cut down that amount. If you are in the flowering / budding stage, make sure
you’re using a formula that’s specifically meant for flowering, or else it could have too
much nitrogen.

If you are not feeding extra nutrients, you may have “hot” soil that has been giving your
plants extra nutrients. In that case, flush your plants with filtered, pH’ed water to help
clear out the extra nitrogen.

Effected leaves likely won’t recover, but you should see the problem halt with no new leaves
being affected.

Wait! I’m not sure if it’s Nitrogen toxicity!

Nitrogen toxicity in marijuana makes clawed leaves that look like talons Ok, you ruled out
overwatering, now what?

When I first got started growing, everyone kept telling me that this particular kind of leaf
clawing was caused by under or overwatering my plants, pH problems, or heat problems.

Yet in my case, I knew that it wasn’t over or under watering (I was growing in hydro, where
roots grow directly in water and air stones are constantly adding oxygen). I knew it wasn’t
pH (my reservoir water had the right pH) and I knew it wasn’t heat since the grow area was
slightly cooler than room temperature.

So then what was really causing my claw leaves?

It’s understandable that other growers were mistaken. It is true that many stresses will
make any other problem worse.

Plus overwatering can cause a similar kind of leaf clawing (learn more below). And if you
do have nitrogen toxicity, than heat or pH problems will make the problem much worse.

Now, you may or may not know that marijuana (or any plant) needs an element known as
“Nitrogen” to grow.

In fact, nitrogen is one of the 3 nutrients that are included in almost every kind of plant food.

When looking at plant nutrients, you’ll almost always see 3 numbers listed,
like 3-12-6 or 5-10-5. These numbers represent the ratio of Nitrogen (N), Phosphorous §
and Potassium (K) contained in the bottle. Just about all plant life on Earth needs these 3
elements to grow.

See the nutrient numbers listed on the front?

The very first number, “3” in the case of the picture to the right, always displays the
proportion of nitrogen in this nutrient bottle compared to the other 2 nutrients
(Phosphorus and Potassium respectively).

The reason nitrogen is in all plant nutrient formulations is because it’s vital to plant processes.

For marijuana plants, when they don’t get enough nitrogen, the bottom leaves start turning
yellow and dying. Left unchecked, a nitrogen deficiency can cause the whole plant to eventually die.

However, this time we’re the dealing with the opposite problem: nitrogen toxicity, or too
much nitrogen.

Why You Should Treat And Prevent Nitrogen Toxicity

Marijuana plants that get too much Nitrogen in the vegetative stage don’t grow as vigorously.

Too much nitrogen is especially harmful in the flowering stage, because this will cause your
plant to produce much smaller buds.

If you react quickly and reduce your nitrogen levels at the first sign of toxicity, your plant
will quickly recover.

Note: Some strains with the word “Claw” in the name tend to do The Claw more easily than others.

Problems with excess nitrogen are not common in the wild; it’s a lot more common to see nitrogen
toxicity on indoor plants, especially when overzealous growers go overboard with nutrients.

Occasionally you’ll come across a strain or particular plant that likes lower levels of
nutrients, and when this happens, it’s important to realize the plant is showing signs of
toxicity, even if all the other plants in your garden seem fine.

One of the most common signs off too-many-nutrients is “nutrient burn,” or when the tips of
your leaf appear brown or burned. Yet there are specific signals your plant will display
when she’s getting too much nitrogen…

Recap: How You Know You Have a Nitrogen Toxicity

Dark green leaves and foliage

Leaf tips turn down, without signs of overwatering.

You may notice yellowing on the affected leaves or other signs of nutrient deficiencies as
time goes on

Nitrogen toxicity is often but not always accompanied by nutrient burn

The Claw often seems random, affecting leaves here and there

Heat and pH problems will make the clawing worse, as they stress out the plant and lower
her defenses, and cause her to drink more water (and uptake more N)

As time goes on, the claw leaves will eventually start turning yellow, getting spots, and

Light and “The Claw”

The distance between the leaves to the lights or irregular light patterns from reflectors often
seem to affect the condition, which is why many growers believe that light is somehow causing
the problem.

You may notice this clawing first appears on dark green leaves that aren’t getting enough light
(they aren’t able to use up all their nitrogen and become nitrogen toxic).

The Claw in the Flowering Stage

If you use vegetative plant nutrients during the flowering stage, then they’ll deliver too
much nitrogen. This is why you need to get special nutrients meant for the blooming / flowering
stage. You’ll notice that flowering nutrients always contain a smaller percentage of nitrogen
(the first number) compared to nutrients for the vegetative stage. Learn more about marijuana
nutrients here.

Many growers mistakenly keep raising nutrient levels or adding additional nitrogen when they
see yellow leaves in the flowering stage, not realizing that it’s natural for plant leaves to
start yellowing as harvest approaches. Adding too much nitrogen in the flowering stage can
cause nitrogen toxicity even when you can see yellow lower leaves. Nitrogen toxicity in
flowering results in smaller yields and airy cannabis buds, so make sure to watch out!

Nitrogen toxic sativa budsNitrogen toxicity in flowering will reduce bud sizeNitrogen toxic
marijuana plant in flowering leaves curl downNitrogen toxicity - too much nitrogen - Cannabis
growing problem

Note: During the last few weeks before harvest, marijuana plants starts pulling all the
remaining nitrogen from her leaves as part of the bud-making process. This causes yellowing
leaves starting towards the bottom of the plant. This is part of the natural flowering process
and you don’t need to fight it. You may notice that marijuana leaves are yellowing in almost
all pictures of marijuana plants with big buds that are close to harvest. You tend to get smaller
yields at harvest from nitrogen-toxic plants with dark green leaves.

It’s Normal For Marijuana Leaves To Start Turning Yellow As Harvest Time Approaches, Don’t Keep
Adding More Nitrogen!

Marijuana plant ready for harvest, notice the yellowing leavess, which is a natural part of the
ripening processIt’s common for leaves to turn yellow towards the end of the flowering stage,
no need to fight it!

I know a lot of marijuana plant problems can look similar, but now that you’re armed with the
right information, you’ll know exactly what to do if you see Nitrogen Toxicity affecting your
marijuana plants.

Nitrogen toxicity - Dark, curled, claw or talon leaves -