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 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.
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
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,
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 Emulsion 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.
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.
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.