Nutrient toxicity/excess/deficiencies and how to solve it.

[Evergreengardener]

Original content from

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@Thomasbruh @Big Terps
And anyone else that may need this. In no way did I write all this up I just sourced it and brought it here for anyone in need!



Macro and Micro Nutrients in a cannabis plant are the elements that are important to plant growth. The three major macronutrients are:

• Nitrogen (“N”)
• Phosphorus (“P”)
• Potassium (“K”).

All cannabis growing nutrients will have these three elements in them. The N-P-K ratios will of your nutrients will be displayed as three numbers such as; 1-2-3. 1, being Nitrogen, 2 being Phosphorus, and 3, being Potassium.
During their vegetative stage, cannabis plants need more “N” and “P”, for energy and growth of leaves and stems. In their flowering-stage, more “P” and “K” will be needed, to build bigger flowers and provide the plants with lots of energy.


Along macronutrients, plants also require micronutrients. They will be used in smaller doses than NPK, but they are still just as important to healthy plant growth.
Some of these micronutrients are Calcium (Ca), Magnesium (Mg), Sulfur (S), Manganese (Mn), Boron (B), Zinc (Zn), and Copper (Cu).

List of Macro and Micro Nutrients in a Cannabis Plant
Below is a list of macronutrients and micronutrients. along with information on how it is used by a cannabis plant. There will also be descriptions of deficiencies and excess for each nutrient.

Macronutrient: Nitrogen
Symbol: N
Uses in Cannabis Growing: Nitrogen promotes photosynthesis, and is directly responsible for the production of chlorophyll. It stimulates leaf and stem growth, and aids the overall size and vigor of the plants.
Nitrogen Deficiency: A nitrogen-deficiency can be recognized by reduced growth-rates and yellowing of the leaves. This will start with the older/lower leaves).


Nitrogen Excess can have lasting health effect on your marijuana plant. You must be able to recognise the symptoms of a nitrogen toxicity, to ensure the best harvest possible.

Nitrogen is an important element of plant growth. Your cannabis plant will take it from the medium, and use to to build stems, branches, and leaves. It is also a major component in photosynthesis. Without it, your plant will no be able to make chlorophyll, which means, it will not eat.

Even though nitrogen is an important element, too much of it can cause problems with weed plants. If these problems are not fixed before the flowering cycle, your plant will struggle to build flowers, or the flowers will be airy and less dense.
Effects of Nitrogen Excess in a Cannabis Plant
With an excess of nitrogen the plant wants to work hard building foliage, and stems, as this is what the plant uses it for. The more nitrogen it has, the more it will try and grow leaves and stems, rather than flowers. Your plant will grow quickly, but it will be weak and spindly.

Because your plant is building so much foliage, it will be very leafy, and the stems will stretch, and become weak. The stems will snap easily, and they will be more prone to bugs and diseases.

What Nitrogen Excess Looks Like in a Weed Plant

• Thick Dark Green Leaves
• Leaves will “Claw” under
• Very Bushy Plant
• Buds will not be dense
• Can leave harvest smelling like grass

How to fix Nitrogen Excess in Cannabis Plants

Nitrogen Excess
How to fix a nitrogen excess will depend on the medium you are growing in. It can be as simple as flushing you medium, or, if growing outdoors, you may have to plant crops that will eat a lot of nitrogen. This will help remove some from the soil.

Nitrogen Excess in Coco & Hydro
Flushing your medium, with plain, PH’d water, is always a good way to reduce the amount of any nutrient in your medium.

Once you have flushed, or removed your old reservoir, feed your plants again, at lower EC. This will lighten them up, to a healthier shade of green, within a week.
If you dont have an EC meter, and youre growing in hydro or coco, you will need one!

Nitrogen Toxicity in Soils
It will be harder to removed any element in soils than it would in hydro or coco, as the drainage isn’t so good and you can risk overwatering your cannabis plants. It is best to do one big flush, to remove as much as possible from the medium. After the flush, let the soil dry out until the pot is light, before watering again.

Once the soil is dry, continue to water your plants, with just water! They will eat the nitrogen that is stored in their plant matter. Your plant will lighten up within a few days, to a week, dependent on how bad the toxicity is.

 

[Evergreengardener]

Macronutrient : Phosphorus
Symbol: P

Phosphorus is the “P” in your N/P/K Ratio. Like Nitrogen and Potassium, it is known as a “Macro nutrient”, and is one of the three main elements needed in plant growth.

Phosphorus is like a power line, connecting all of your plants cells together. The energy created by the plant via photosynthesis, is transported around the plant using phosphorus. It is also a major element in flower, and root growth.


Because flowers are also built out of Phosphorus, you will find bloom foods, and P/K boosters will be high in phosphorus.

Uses in Cannabis plants: Phosphorus aids in the germination of seeds, and the growth of seedlings and roots. It is also vital the production of terpenes, resins, flowers, and starches. Phosphorus also influences overall plant vitality.

Phosphorus Deficiency: A phosphorus-deficiency will cause a cannabis plants growth-rates to slow down. Also smaller leaves which wilt. The leaves will be a dull, bluish-green, which will turn purplish or bronzy, and will have seared edges.



The Effects of Phosphorus Excess.
Phosphorus Excess can be a difficult problem to diagnose. This is is because too much phosphorus will cause other nutrients to be “locked out”. You will see signs of cal/ Mag deficiency, because the plant can not absorb those nutrients. This will also affect plant growth, and will cause many issues, that will progressively get worse.

What Phosphorus Excess Looks like

How to Fix Phosphorus Excess
How to fix a phosphorus excess will depend on the medium you are growing in. It can be as simple as flushing you medium, or, if growing outdoors, you may have to plant crops that will eat a a lot of phosphorus. This will make sure whatever is in your soil will be eaten faster.

Phosphorus Excess in Coco & Hydro
Flushing your medium, with plain, PH’d water, is a good way to reduce the amount of any nutrient in your medium.

Once you have flushed, or removed your old reservoir, feed your plants again, at half of their usual EC. This will lighten them up, to a healthier shade of green, within a few days. But any damaged or burnt leaves will not fully recover.

If you don’t have an EC meter, and you’re growing in hydro or coco, you will need one! If you would like to know what your plant is eating, you need a good reliable EC meter.

Phosphorus Excess in Soils
It will be harder to remove any element in soils than it would be in hydro or coco, as the drainage isn’t so good and you can risk over watering your plants. It is best to do one big flush, to remove as much as possible from the medium. After the flush, let the soil dry out until the pot is light before watering again.

Once the medium is dry, continue to water your plants, with just water! They will eat the Phosphorus that is stored in their plant matter. Your plant will lighten up within a few days, to a week, depending on how bad the toxicity is.

 

[Evergreengardener]

Potassium, is the “K” in your N/P/K Ratio. Like Nitrogen and Phosphorous, it is known as a “Macro nutrient”, and is one of the three main elements needed in plant growth. Here will will discuss Potassium Excess, this is when your plant has too much Potassium.

Potassium helps the pores of the plant open and close, which essentially, allows it to sweat and breathe. It is also responsible for the production of many enzymes the plant needs to grow. With out it, the plant would not be able to produce the starches needed for photosynthesis.
Macronutrient: Potassium
Symbol: K

Uses in cannabis plants: Potassium is important to your cannabis plants for metabolic changes during flowering, and the production of flowers. It also promotes general plant-vigor, disease-resistance, and strong growth.

Potassium Deficiency: A potassium-deficiency will slow down growth-rates. It will also cause leaf-tips and edges to become a scorched-brown colour, with curled margins.




Too much potassium can cause the plant to have “lock out”. This will stop the plant from eating other vital elements, and other deficiencies will soon show. If not solved quickly, it can have a lasting effect on your harvest.

The Effects of Potassium Excess.
Because Potassium excess will cause lock out of other nutrients, it can be wrongly diagnosed. Look at out for the top leaves growing thin blades. Middle leaves will develop burn around their tips. Flowering will be slow to start, and flower growth will be diminished.

What Potassium Excess Looks like

How to Fix Potassium Excess
How to fix a potassium excess will depend on the medium you are growing in. It can be as simple as flushing your medium, or, if growing outdoors, you may have to plant crops that will eat a a lot of K. This will make sure whatever is in your soil will be eaten faster.

Potassium Excess in Coco & Hydro
Flushing your medium, with plain, PH’d water, is always a good way to reduce the amount of any nutrient in your medium.

Once you have flushed, or removed your old reservoir, feed your plants again, at half of their usual EC. This will restore their colour, to a healthier shade of green, within a few days. But any damaged or burnt leaves will not fully recover.
If you don’t have an EC meter, and you’re growing in hydro or coco, you will need one! If you would like to know what your plant is eating, you need a good reliable EC meter.


Potassium Excess in Soils
It will be harder to remove any element in soils than it would be in hydro or coco, as the drainage isn’t so good and you can risk over watering your plants. It is best to do one big flush, to remove as much as possible from the medium. After the flush, let the soil dry out until the pot is light before watering again.

Once the medium is dry, continue to water your plants, with just water! They will eat the potassium that is stored in their plant matter. Your plant will lighten up within a few days, to a week, depending on how bad the toxicity is.

 

[Evergreengardener]

Micro Nutrients in a Cannabis Plant
Element Name: Calcium
Symbol: Ca

Uses in Cannabis Plants: Calcium is a key ingredient in cell-walls. It strengthens stems, stalks and branches. It also contributes to root-development/growth, mostly that of the root-tips.

Calcium Deficiency: Calcium-deficiency can be recognized by distorted leaves, with hooked tips and curled margins. A deficiency would also result in under-developed roots, with weak root-tips.

Calcium Excess: Red and orange spots will develop on leaves. Your plants will also suffer from nutrient lock out and show signs of many deficiencies.

 

[Evergreengardener]

Micro Nutrients in a Cannabis Plant
Element Name: Magnesium
Symbol: Mg

Uses in Cannabis Plants: Magnesium is significant for chlorophyll-production and most enzyme reactions. It is responsible for healthy leaf-structure and production, as well as sustaining healthy vein-structure in the leaves.

Magnesium Deficiency: A magnesium deficiency will affect various plant species differently. The most common symptoms in cannabis plant are a vivid yellowing of the leaves, followed by leaves falling without withering, starting with the older/lower leaves.

Magnesium Excess: Excessive “Mg” levels may initiate a calcium-deficiency. Leaves will be dark, and show signs of salt build up, with leaf tip burns.

 

[Evergreengardener]

Micro Nutrients in a Cannabis Plant
Element Name: Sulfur
Symbol: S

Uses in Plants: Sulfur, being an ingredient in plant-proteins, is vital for protein-production, chlorophyll-production and vegetative growth.

Sulphur Deficiency: A sulfur deficiency can be identified by slowed down growth-rates. This will also be accompanied by small, mutated leaves which are round in shape and roll upwards. Also, leaves will become stiff and brittle, and will fall off. A “S” deficiency will also cause flowers on the top of colas to die.

Sulphur Excess: General nutrient burn, with dark green leaves. A plant with sulphur excess will grow shorter with uneven growth.

 

[Evergreengardener]

Micro Nutrients in a Cannabis Plant
Element Name: Manganese
Symbol: Mn

Uses in a Cannabis Plant: Manganese is a catalyst for many enzymes, and also aids photosynthesis/ chlorophyll-production.

Manganese Deficiency: Firstly, you must consider a manganese-deficiency will have varying symptoms, depending on plant-species. The most common symptoms in cannabis plants are a yellowing of chloroplasts while stems remain relatively green. White or grey specks/spots may develop on the surfaces of leaves. As is usually the case, older/lower leaves will be affected first.

Manganese Excess: Excessive “Mn” levels may cause an “Fe”(iron) deficiency, which will exhibit symptoms similar to a “Mn” deficiency. New leaves will develop orange , to brown, coloured patches.

 

[Evergreengardener]

Micro Nutrients in a Cannabis Plant
Element Name: Boron
Symbol: B

Uses in Cannabis Growing: Boron aids the movement of necessary sugars, as well as reproduction, and water intake by cells. It also assists in the production of stems, stalks and branches, and keeps calcium in a soluble form. Furthermore, “B” contributes to leaf-production:-colouring and structure.

Boron Deficiency: A boron deficiency can be recognized by symptoms such as; distorted and dead growing tips, hollow stems, and malformed flowers. Plants suffering from a “B” deficiency frequently exhibit scorched, curled leaves, which are often spotted and discolored; young/vegetative leaves are affected first.

Boron Excess: Excessive “B” levels may cause plants to exhibit symptoms similar to those of “Mg”/”K” deficiencies. Leaves will droop, and begin to turn yellow.

 

[Evergreengardener]

Micro Nutrients in a Cannabis Plant
Element Name: Zinc
Symbol: Zn

Uses in Cannabis Plants: Zinc levels directly affect plant size and maturation, as it is necessary for the production of plant proteins. Consequently, “Zn” is vital to the production of leaves and stalks/stems/branches.

Zinc Deficiency: A deficiency of zinc will result in the yellowing of chloroplasts between leaf veins, usually with purplish spots of dead cells on leaf surfaces. You will find older/lower leaves are the first to show symptoms. Vegetative growth is deformed, and floral growth is reduced.

Zinc Excess: Excessive “Zn” levels can initiate an “Fe”(iron) deficiency. But this is very rare as it is only found in small amounts in cannabis growing nutrients.

 

[Evergreengardener]

Micro Nutrients in a Cannabis Plant
Element Name: Copper
Symbol: Cu

Cannabis Plant Uses: Copper is responsible for healthy, vigorous growth, and strengthens stalks/stem/branches. It is also necessary for the production of plant proteins, and is crucial for reproduction.

Copper Deficiency: A copper deficiency can cause otherwise green leaves to adopt a bluish hue. As a result of copper deficiency, vegetative growth may fail to unfold, and may be yellow at the tips and edges.

Copper Excess: Roots will become thick, slow down in growth, and in worse cases, will root and die. The plant will be less bushy, because it will grow less stems.


Final notes on Macro and Micro Nutrients
If your plants are suffering with micronutrient deficiency, adjusting your PH can probably fix it. This will bring the PH of the medium back into the correct range, and will result in the Macro and Micro Nutrients available again.

 

[Macky]

Hi guys, I am the one who wrote all of these posts over at Percysgrowroom.com

I dont mind any one using our content but please be so kind to leave us a back link in the posts

 

[Evergreengardener]

Hi guys, I am the one who wrote all of these posts over at Percysgrowroom.com

I dont mind any one using our content but please be so kind to leave us a back link in the posts

Nice to know man you can see I did state I didn’t write them up but I didn’t know where to credit as they’ve been saved in a folder on a computer for a long time now and I didn’t know where I originally got them from.

 

[Evergreengardener]

Hi guys, I am the one who wrote all of these posts over at Percysgrowroom.com

I dont mind any one using our content but please be so kind to leave us a back link in the posts

Actually I now see if you click the pics some of them take you to you’re site so there is a back link

 

[J.James]

Linked at the top of the page. Thank you @Macky for all the time you put into these writeups

 

[Evergreengardener]

Linked at the top of the page. Thank you @Macky for all the time you put into these writeups

Thanks bro the first pic is also a link back to the original site.

 

[NoWaistedSpace]

If you notice, most troubles can be solved with a good "flush". (If you have enough aggregate, like perlite, to allow for good drainage)
Are you flushing the right way is the question?
I will use a sprayer and spray my medium and outside of my "felt" pots. Soak them pretty good. I am trying moisten and loosen the accumulated salts. I'll wait 15 mins or so, then begin the flush. You want a good bit of run off. Maybe repeat the process if your drain waste is high in salts. Let them set in the water for a bit.
Then, set them up so they will drain completely. I set mine on a ceramic tile with the flutes facing up.
Hydroton or rocks etc. will work.

 

[Evergreengardener]

If you notice, most troubles can be solved with a good "flush". (If you have enough aggregate, like perlite, to allow for good drainage)
Are you flushing the right way is the question?
I will use a sprayer and spray my medium and outside of my "felt" pots. Soak them pretty good. I am trying moisten and loosen the accumulated salts. I'll wait 15 mins or so, then begin the flush. You want a good bit of run off. Maybe repeat the process if your drain waste is high in salts. Let them set in the water for a bit.
Then, set them up so they will drain completely. I set mine on a ceramic tile with the flutes facing up.
Hydroton or rocks etc. will work.

I don’t use salt nutes I’ve never “flushed” a plant

 

[Old ST1R]

Hi guys, I am the one who wrote all of these posts over at Percysgrowroom.com

I dont mind any one using our content but please be so kind to leave us a back link in the posts

I found pretty much the same content here:

https://www.loudclouds.co/wp-content/uploads/2016/07/marijuana-deficiency-chart-jorge-cervantes.jpg

Did Jorge Cervantes borrow your stuff too? I mean the drawings and notes are identical and the website “Marijuanagrowing.com” is Jorge’s website where he sells his books, so who does this really belong to?

 

[Macky]

I spoke to Jorge myself and he is fine with it, I also sent him a lot of picture for his up coming book which our site also gets a shout out in

 

[Macky]

But the main pics at the top of the NPK def and Excess were all made by me.... took ages!! lol. I'm going to be making some new ones soon.

Thanks for putting the back link too guys, I am glad this content is useful to people, no matter what site it is on