Nitrogen deficiency how long to repair?

Hi lovely people.
Has been awhile since I’ve posted as I have not really needed to ask questions as the plants seem to have been going well to date. I’m growing organically and I have a couple of Black Domina clones. I’m fairly sure they have a nitrogen deficiency as I am getting bottom leaves yellowing and falling, and the last few days they’ve been a bit droopy. I am growing organically and a few days ago added a top dressing of, alfalfa meal, seabird guano, and kelp meal. How long would it take the top dressing to take affect? I don’t want to add any thing else in case I end up with a nitrogen toxicity.

Medium- 1/3 of compost, perlite and coco.
Light - mars hydro tws 2000
Notes- worm juice, super grow,

First time adding the top dress of alfalfa, kelp, guano.

1 Like

If that was the only leaf to yellow off, I wouldn’t be too concerned. Bottom leaves in the shade will do that as the plant ages.
Looks great, and you seem to have it fully under control.

The problem with plastic containers is that it easy for cannabis to outgrow them and become root bound. Keep an eye on soil moisture, and consider transplanting to a cloth pot before flowering.


Really? Wow thanks. Worrying about nothing then.:grinning:

PS, so the dropping could be heat related? We have had a few really hot days of 40c and above.

1 Like

That’s really hot.
I don’t see tacoing leaves, but she may need more frequent watering.
What’s your rh look like?

I’d try to get that heat under control. Not only will inhibit proper growth, it’ll burn off terpenes and reduce the quality of bud during flower.

1 Like

Yes they will be transplanted to cloth pots very soon as I’m planing on flipping in the next week.

rh? Presume you mean pH? It’s between 6.2 to 6.5.

1 Like


Some where on the bags should be the N P K you need to see what the N is and what you had given it before this all happened.

I was looking at your plant and the dark green is a dead give a way plus the drooping leaves and the starting of yellowing leaves at the bottom. So you really need to find out what that n p k is on the bags. Hopefuly you havent watered yet. Top coating can be taken off.

Here is a pick of " NITROGEN DOXICITY

Nitrogen Toxicity

Nitrogen toxicity - too much nitrogen - Cannabis growing problemProblem:
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 over-watering, 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.

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

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 (P) 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?


Keep in mind that being in media (which you are), an excess can look like a deficiency or show both excess and deficiency. Lower fans yellowing is normal as the plant gains canopy.

Growing organically is tough and you have to bring your ‘A’ game.

@Mrcrabs is an organic grower IIRC.

1 Like

I had another closer look at the tips of the leaves and there is some tip damage. I had nitrogen toxicity with the mother plant and this looks different. The other plant did have the clawing and they were super green!

There does not seem to be any NPK for worm juice :-). I read that you cannot damage, or put too much, worm juice but I have diluted it 50-50. I’ve added the photos and directions of the new nutrients, which I’ve only used as a top dressing.

The Super Grow was recommended by the local hydro store.

1 Like

All good stuff it looks like. I have used worm castings and teas and it is a wonderful adjunct in soil and the plants do love it. It also buffers close to 7.0 which is fairly benign for the plants.

The thing is if you are feeding as main source of nutes (which you are) then you really need to know what the solution concentration is at feeding. You can overdo it in strength (or under do it!) and cause issues including lockouts that will look like a def. I’m also leery of any product that doesn’t list ingredients. Frankly I would look at something else, unless you get some guidance on that specific product. I looked it up and they provide no info.

1 Like

Think you hit The nail on the head mate. I repotted The droopiest one and guess what I saw…a mass of white roots. She looks a lot perkier this morning and I’m sure she is saying… Thanks mum!

Just have to wait for my order of fabric pots to arrive and the rest will be transplanted.

This lady is Critical Orange Punch.

1 Like