Spot Nitrogen Deficiency with Marijuana and Recover in a Week!

 Yellow leaves, stunted growth.


These can be signs of a nitrogen deficiency with your marijuana plants.

If not corrected soon enough it can spread quickly and will affect the health of your plant in a major way.

But not to worry it’s an easy fix you just need to dial in the nutes(nutrients).

First, let’s take a look at nitrogen to learn why it is so important for cannabis plants.

Time for a little science.

Nitrogen molecule

Nitrogen is an essential nutrient cannabis needs.

It helps with photosynthesis, transporting amino acids, and increases the plant’s immunity.

Without it, there is no plant growth. 

The other essential nutrients are phosphorus and potassium.

N-P-K values appear on the labels of nutrients you purchase, with different amounts for the stages of growth.

N stands for Nitrogen

P stands for phosphorus

K stands for potassium.

The way nitrogen deficiency starts is it begins from the bottom of the plant and works its way up through the stems and branches. According to Penn State University.

You may have noticed some of the lower leaves a pale green to yellow color.

This is a sign of a lack of nitrogen with your marijuana plants.

With not enough nitrogen, it affects the oldest leaves first by removing the chlorophyll from the leaf.

To provide for the upper leaves, so the plant continues to grow.


Vegetative Stage

When you are growing in the vegetative stage, it’s best to look for nutrients that have a higher Nitrogen level and a lower Phosphorus and potassium level.

You may have noticed this on nutrients for vegetative growth.

Most nutrients brands out there have a “GROW” or vegetative stage nutrients for your cannabis plants. Some even come in a 3 part complete grow cycle.

Nitrogen is essential for early plant growth.

Cannabis plants and all plants in general need nitrogen because it is an essential building block for the plant to produce protein.

It is required to make chlorophyll so the cannabis plant can convert the light into energy for the plant

Ninety percent of the time nitrogen is an issue in the vegetative stage

Flowering Stage

When you move on to the flowering stage, your cannabis plants will require less nitrogen and more phosphorus.

The phosphorus helps with the blooming of the flowers on your herb.

During the last weeks of flowering, the marijuana plant will start to gain yellow leaves.

This is natural and do not be too concerned at this stage of the game.

You can also have nitrogen deficiency during flowering at the beginning, just add additional nitrogen to your plants if you start to see weak growth and other signs such as yellow bottom leaves.

If you are using a 3 part nutrient formula that requires the use of all three different nutrients.

For example general hydroponics flora series, or lucas three part grow solution.

You will want to make sure your using them the whole grow cycle. You may notice some of the leaves rapidly changing if you just use the bloom.

If you notice too much nitrogen during flowering, flush your plant with water and introduce a pk booster and lower the nitrogen levels by switching to blooming nutrients.

Signs of Nitrogen Deficiency

  • Leaves start turning pale green
  • Red stems
  • Yellowing of the lower leaves
  • Browning of leaves
  • Yellowing of the veins of a marijuana leaf
  • Leaves drooping
  • Looks like over watering 
  • Wilting Leaves break off
  • Slow growth rate during vegetative stage

How to Fix Nitrogen Deficiency

The easiest ways to fix your nitrogen depleted cannabis plants is to do the following:

  • Start using a nitrogen-rich nutrient for your veg cycle if not already.
  • Add extra nitrogen rich supplements to your regular feeding schedule.
  • Add additional vegetative fertilizer in small increments
  • Check the PH balance of your run off to make sure your having a proper PH level so the plant can uptake the nitrogen. Adjust accordingly.
  • Use a foliar spray on the under side of your leaves before the lights go out.
  • A small dose of cal mag can even make a difference in the uptake of nitrogen.

Your marijuana plants should recover within a week after providing more nitrogen to your plants.

The yellow leaves will not recover unfortunately and will have to be removed from the plant if you have not already done so.

 Watch this quick video for hands on view,

Natural Ways

Here are some natural ways to fix your nitrogen deficiency, just add the additive to your grow medium and or your nutrients as directed.

Composted manure is recommended for growing your marijuana plants outdoors, naturally due to the smell.

Bat guano which can be found in some organic fertilizers (one being from Fox Farms called Big Bloom). They also have straight up guano is 4 lb bags by Happy Frog.

Dr. Earth Fish Meal that is rich in nitrogen can be added to both growing outdoors and indoors as well to help boost those nitrogen levels. With 9-4-1 values.

Fish Emu​l​sion is a liquid fertilizer addition that can be added when watering. It’s usually a 5-1-1 mix for getting those plants to perk right up.


Organic Nutrients

There are many organic nutrients on the market that are available online or at your local grow shop.

Theses are a must for any grower and should be included in your grow.

Here are just a small few that can help you grow some nice healthy plants.

Raw Nitrogen by NPK industries is great for adding to your plants when you have a deficiency with nitrogen.

The values are 20-0-0 so your getting pure nitrogen to your plants and nothing else.

Its doesn’t contain nitrates and urea like some other nitrogen only solutions out there.

Raw nitrogen can be used during the entire grow if required or to fix a nitrogen deficiency.

Grow Big from Fox Farms is another great nutrient for your veg phase it has a 6-4-4 value. It’s a Organic and is ideal for all types of growing.

Grow Big works well with Big Bloom during the first stages of growth. With additional Bat guano.

Botanicare Pure Blend Pro Grow is a little lower on the nitrogen at 3-2-4 and organic blend that inhibits lush vegetative growth. It works well with all types of growing.

Signs of Excessive Nitrogen

  • Leaves curling downwards (nitrogen claw)
  • Dark green leaves
  • Brittle stalks and stems
  • Weak Immune system
  • Easy prey for Insects

There is always a downside of providing too much nitrogen to your cannabis plants is turning the leaves a dark green.

Excessive nitrogen affects the stalks and stems of the plant making them brittle and-and the immunity of the plant is jeopardized as well, allowing for diseases or an insect invasion.

Just lower how much nutrients you are currently feeding the plants.

You can also flush your plants with water and start with a lower nutrient cycle if you feel it’s necessary.

It’s all a matter of finding the proper balance for the different stages of growth.

Final Thoughts


If you start to notice the symptoms of nitrogen deficiency with your marijuana plants, always act fast and you should recover within a week.

Some strains of cannabis need more nitrogen than others, just the same and some are sensitive to nitrogen and need less.

The same goes for other beneficial nutrients.

It’s a matter of trial an error when growing, especially with new strains.

But once you dial it in you and your plants will be happy.

Let me now in the comments what worked for you or if this helped you recover.

Grow on my friends.

Image credits : Image 

22 thoughts on “Spot Nitrogen Deficiency with Marijuana and Recover in a Week!”

  1. I’m panicking because it’s my very first plant and I was pretty much watching it die right before my eyes. So gonna follow your instructions and see. Wish me luck
    Thanks so very much

      • My Indica is In week four of flower and it has gone light green in colour from the outside in and has some dry crunchy to the feel leaves. I have been using advanced nutrients, grow, micro, bloom, budcandy and big bud. I just got a cal mag supplement and starting adding In but after two feeds of cal mag and 3 days of hoping it will darken back up still nothing.

        • maybe up the grow nutes a little but more that usually have nitrogen in it. Tough call on what may be wrong mid way thru flower right now. in the next couple week they will be using less nitrogen and more phosphorus and potassium.

  2. What do you feel about rabbit manure to raise nitrogen? I’ve been giving straight filtered tap that sits out for 24 hours water ph around 6.5 to a supersoil mix I bought online. They’ve been going for 6 weeks in veg and started showing yellow down on the bottom I had them in 3 gallon smart pots and moved them to 5 gallon thinking I’d refresh the soil though they’re still yellowing. My buddy brought rabbit manure over and said it has a slow release N 2.4 P 1.4 K 0.6 saying this will fix it. He grows tomatoes and uses it in his garden I’m just hesitant but also at the moment cash strapped till Friday so was thinking about top dressing and watering in would love your comment on this.

  3. I’ve had two plants turn yellow overnight in Week 7 now. I’m talking 85% of the plant turning bright yellow with some larger fans coming loose & falling off. I know nitrogen deficiency is common, but how the HECK does it happen so suddenly? How can a plant go from green & healthy to completely yellow in a 24-hour period? TWICE!!!

    The first time it happened, I was growing in a Solo cup & had just fed some concentrated banana tea. I was just sure that was the cause: rootbound & a pH problem or over-fertilizing. But now my 2nd plant in a 3-gallon fabric pot has done the same exact thing at the same time! It’s actually worse this time around–I was able to reverse most of it in the Solo cup by applying diluted urine & grass tea. The color returned to most of the yellow leaves last time. Not so with this plant.

    I don’t have the funds to buy nutrients right now so I’m just trying to hang on until harvest. Any common household items/ingredients that contain fast-acting nitrogen? I’m at a loss here.

  4. Hi my bottom leaves are turning yellow my plants are still very young,
    is it nutrients? im giving water and food as store told me, with right ph level.

    What to do?

  5. Thanks so much for the info. One of my plants has bad nitrogen deficiency not sure if phosphorus too cause stems are purple (almost all) . this happened over a 2 week period because I transplanted into a 4 gallon and watered without nutrients and the pot has now taken 2 weeks to dry out so I can water again with nutrients and in the while its growth came to a halt. If I feed now you say it will take about a week I really hope so. I was not going to water with nutrients as I have destroyed many a plant by over watering and I learned to wait it out even if the plant needs food. I just foliage fed but it didn’t seem to prevent this starvation. I guess I did the best out of that situation?

  6. Quick question for everyone in this we have been growing for maybe two months 3 months now and are completely new to this we have just figured out that our plans have been nitrogen deficient my question is if we have replanted them in Fox farm soil from using miracle grow which in hindsight was a bad idea now that I know do still need to add more nitrogen

  7. Could I use fox farm grow big during flower for nitrogen def to bring it back?? I have been using tiger bloom keep getting yellow slow dieing leafs??

  8. I been growing 2 plants one is budding and some of the new leafs are a hint of yellow not much is that normal this is my first plant that I’ve gotten to the flower stage .
    My mendos breath though has a weak steam n is yellowing at the bottom leafs I read all the comments so I’m confident it’s nitrogen definitely now any pointers ?

    • I would check the nutes your using and add more of the one that has the nitrogen added to it. or you could supplement with some raw nitrogen, be careful do not need that much or there is bat guano, check the post if you need more or different recommendations.

  9. I have 5 plants and i noticed what I think is a nitrogen deficiency, im using ffof soil moxed woth roots organic coco and ewc and roots organic uprising grow they are on week 4 and starting of flower when i noticed the deficiancyw which was about 4 days ago so i top dressed with more ewc and roots organic grow and some roots organic terp tea bloom but still they havent recovered I know it takes time to recover and also break down the organic nites but how long till roots organic uprising starts working? Im worried its my first grow and they was doing so good then they stopped growing right as the auto flowers started to flower help

    • Not sure when your roots organic uprising will work. I don’t grow that way with top dressings. I use cyco flower nutes right now with my coco grow. I also do not grow autos, but if they are in flower my guess is that yes they will stop growing. and start to produce buds now, it’s in the flower stage now.


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