420 Magazine Background

Nutrients Explained, How the Plant Use What you give them!


New Member
Ok so i subscribe to the old GI Joe saying,

"Knowing is half the battle!"

So i was wondering what EXACTLY what the plant uses its NPK and micro/macro nutes. So in the search for the holy grail, i stumbled upon this article that i think breaks down how they uses each nute very well.

Its not only important to know HOW to grow, when to feed, when to water, how much light you need, air, pests, ext...... but to know WHY the plants grow. What is it that the plants like that make them perk up and say HELLO!!! Its like a relationship with your plants, you have to listen to them, know that they want and give it to them.

Take this info and apply it to your grow, read up on the nutes you already have, and mabe you will learn that you need to add a micro nute to your mix! :goodluck:

Primary, Secondary & Micro Plant Nutrients

Plant Nutrients
Sixteen chemical elements are known to be important to plant growth and survival. The sixteen chemical elements are divided into two main groups: non-mineral and mineral. The non-mineral nutrients are hydrogen (H), oxygen (O), & carbon (C).
These nutrients are found in the air and water.
In a complex process known as photosynthesis, plants use energy from the sun to change carbon dioxide (CO2 — carbon and oxygen) and water (H2O- hydrogen and oxygen) into starches and sugars. These starches and sugars are then utilized by plants as food.

In their natural environment, plants obtain carbon, hydrogen, and oxygen from the surrounding air and water. So it follows that when managing an indoor hydroponic garden, among other environmental conditions, one must carefully control the lighting, water and ventilation systems to provide adequate amounts of these essential materials which are otherwise lacking in such artificial environmental conditions.

Mineral Nutrients
The 13 mineral nutrients which come from the soil are readily dissolved in water and absorbed through a plant's roots. Depending upon soil composition, there are not always enough of these nutrients available in the root zone to facilitate healthy plant growth. This is why plants generally respond so well when nutrient fertilizers are added to the soil.
The 13 mineral nutrients are divided into two separate groups: Macro-nutrients and Micro-nutrients.

Macronutrients themselves are further divided into two separate groups: NPK, or primary nutrients, and secondary nutrients which are required in smaller amounts, but are no less important to plant function and development.

The primary nutrients are nitrogen (N), phosphorus (P), and potassium (K). The percentage of NPK amounts found in chemical and organic fertilizers are usually displayed with three bold numbers on the product label. These three mineral nutrients are required in large quantities and benefit plants in the following ways:

· Necessary for formation of amino acids, the building blocks of protein
· Essential for plant cell division, vital for plant growth
· Aids in production and use of carbohydrates
· Directly involved in photosynthesis
· Necessary component of vitamins
· Increases foliage and plant vigor
· Affects plant energy reactions

· Facilitates photosynthesis, respiration, energy storage and transfer, cell division
and enlargement
· Improves quality of fruits, vegetables, and grains
· Helps plants survive harsh winter conditions
· Promotes early root formation and growth
· Increases water-use efficiency
· Stimulates plant metabolism
· Vital to seed formation
· Hastens maturity

· Carbohydrate metabolism and the break down and translocation of starches
· Activates enzymes and controls their reaction rates
· Increases disease and cold resistance
· Improves quality of seeds and fruit
· Essential to flower development
· Increases water-use efficiency
· Essential to protein synthesis
· Important in fruit formation
· Improves winter hardiness
· Increases photosynthesis

The secondary nutrients are calcium (Ca), magnesium (Mg), and sulfur (S).

· Increases fruit set
· Regulates plant respiration
· Stimulates microbial activity
· Involved in nitrogen metabolism
· Essential for nut development in peanuts
· Utilized for Continuous cell division and formation
· Aids translocation of photosynthesis from leaves to fruiting organs

· Improves utilization and mobility of phosphorus
· Activator and component of many plant enzymes
· Influences earliness and uniformity of maturity
· Key element of chlorophyll production
· Increases iron utilization in plants
· Aids in seed germination

· Aids in seed production
· Integral part of amino acids
· Helps develop enzymes and vitamins
· Promotes overall growth and maturity
· Promotes nodule formation on some plants
· Necessary in chlorophyll formation (though not a constituent)

Micronutrients are those elements essential for plant growth which are needed in only very small (micro) quantities. These elements are sometimes called minor elements or trace elements, but use of the term micronutrient is encouraged by the American Society of Agronomy and the Soil Science Society of America.

The micronutrients are: boron (B), copper (Cu), iron (Fe), chloride (Cl), manganese (Mn), molybdenum (Mo) and zinc (Zn).

And even though plants require micronutrients in far lesser quantities than macronutrients, they are just as important for plant development, overall health, and crop yields. Most of the micro nutrients serve as plant activators and as such are critical to many plant functions.

The following is a brief summary of the functions which micro nutrients perform:

· Essential for germination of pollen grains and growth of pollen tubes
· Essential for seed and cell wall formation
· Affects nitrogen and carbohydrates
· Necessary for sugar translocation
· Promotes plant maturity

· Interferes with phosphorus uptake
· Controls water loss and moisture stress
· Enhances maturity of small grains on some soils

· Intensifies color
· Increases sugar content
· Catalyzes several plant processes
· Major function in photosynthesis
· Major function in reproductive stages
· Indirect role in chlorophyll production
· Improves flavor of fruits and vegetables

· Acts as an oxygen carrier
· Promotes formation of chlorophyll
· Reactions involving cell division and growth
· Activator for enzymes that control respiration

· Essential in phosphorous and magnesium uptake
· Functions as a part of certain enzyme systems
· Increases the availability of P and Ca
· Aids in the utilization of nitrogen
· Aids in chlorophyll synthesis

· Aids in the formation of legume nodules
· Needed to convert inorganic phosphates to organic forms in the plant
· Required to form the enzyme "nitrate reductas" which reduces nitrates to ammonium in plants

· Essential for protein and growth hormone synthesis
· Necessary for chlorophyll production
· Necessary for carbohydrate formation
· Necessary for starch formation
· Increases leaf and fruit size
· Aids plant enzyme system
· Aids in seed formation

In addition to the 13 nutrients listed above, plants require carbon, hydrogen, and oxygen, which are extracted from air and water to make up the bulk of plant weight.

Organic Versus Chemical Fertilizers
Although organic and natural fertilizers usually have a lower NPK number, they are nevertheless valuable soil amendments that work slowly over time to improve soil quality, and thus effectively empower plant growth. Natural fertilizers do not induce the fast growth and flowering provided by chemical fertilizers that can actually weaken plants. Therefore, big NPK numbers don't necessarily mean a better fertilizer.

Organic composts and composted manure are excellent sources of all nutrients plants require for healthy growth, including NPK. Professional gardeners often use a combination of both chemical and organic / natural fertilizers in order to utilize the advantages of each. And many professional gardeners agree that using compost is among the best methods of providing a well-balanced supply of nutrients.

Other excellent sources of natural plant nutrients are humic acid, sea weed, fish meal, bone meal, alfalfa meal, bat guano and earthworm castings.


"That's right boys and girls!"


The other half is DOING!!! So get out there and grow some green in the good USofA! :peace:


New Member
I was doing more research on nutrients and liked how this broke down lil different on HOW to use the npk a lil diffrently.

Understanding how and when to fertilize is an important part of growing marijuana. Each bag or bottle of fertilizer is labeled with a set of numbers representing three of the macro-nutrients used by plants. These numbers are always in the same order and correspond to the specific plant nutrients nitrogen, phosphorous, and potassium (N-P-K). If you hadn’t guessed, the symbols N, P, and K are the same as used on the Periodic Table of Elements. An exception to this method of labeling is found in Australia where a fourth letter is assigned for Sulfur (S).

N-P-K value labeling is highly regulated by the country or state in which the fertilizer is intended to be sold. The value listed on fertilizer packaging for N is calculated by the percentage by weight. For example if the N-P-K reads 12-1-1, then the product is 12% nitrogen by weight. The labeling methods used for phosphorous and potassium are more complicated and do not represent the raw elemental values. Phosphorus is measured by its content of oxides while potassium is measured by its soluble compounds. This is important to understand because some fertilizers may contain much more of these nutrients than their manufacturers are allowed to print on the packaging. It should be noted that some fertilizer companies circumvent regulations by printing soluble and insoluble nutrient percentages on their labels.

Nitrogen (N)

Most of what you breathe is nitrogen, an odorless, colorless gas that constitutes over 75% of Earth’s atmosphere. Despite the overwhelming presence of atmospheric nitrogen, there are only a few kinds of plants in the legume family that can make use of it. Marijuana is not a legume, so nitrogen must be supplemented.

Synthetically-produced nitrogen fertilizer is made in the form of anhydrous ammonia from natural gas. Anhydrous ammonia is then usually converted into ammonium nitrate for storage and ease of application. Once granulated, the ammonium nitrate is ready for use as a cost-effective and easy-to-use plant food. Natural sources of nitrogen are numerous and include; blood meal, manure, bird and bat guano, among many others.

Because of its crucial role in photosynthesis, fertilizers high in nitrogen are used during the ‘vegetative’ phase of growing marijuana. Nitrogen is key to both chlorophyll and protein production and used throughout photosynthesis for the conversion of carbon into sugars and other organic compounds.

  • Grow fertilizers are high in nitrogen
  • Used for rapid growth
  • Used to build chlorophyll and promote a healthy green color
  • Improves volume and health of plant foliage

Phosphorus (P)

Phosphorous is a volatile and reactive element, which is why it is probably never found in its pure elemental form in nature. Because of this volatility, fertilizer packaging is actually showing a measure of its oxide (P2O5). Phosphorous is commonly refined from stone called phosphotite or mined from ‘guano islands’ comprised primarily of bird and bat dropping. A common biomass source of phosphorus is found in ground bone (bonemeal).

Marijuana plants use phosphorus throughout their growing cycles but at elevated levels when flowering. As the plants’ nutrient requirements change, the feeding schedule is adjusted to include ‘bloom foods’ with higher levels of phosphorus and lower levels of nitrogen. Because plants also use Phosphorus in root formation, low doses of it are often found in cloning solutions.

  • Bloom foods are higher in phosphorous
  • Improves bud production
  • Aids root development
  • Involved in oil and glucose production

Potassium (K)

Potassium is an alkali metal that reacts violently with water and oxidizes quite rapidly when exposed to air. This unstable nature requires that it be added to fertilizers in the form of potassium compounds known as potash. Not all forms of potash are suitable for plants; K2SO4 , K2SO4, 2MgSO4, and K2Mg2(SO4)3 are the three that seem the best suited for a plant’s needs. It should be noted that potassium oxide (K2O) is never used for fertilizer as it is caustic and hygroscopic. Like phosphorus, potassium is mined from mineral-laden ore.

Like N and P, potassium (K) is a key component in the metabolic functions of plants and plays a large role in the production of proteins and photosynthesis. Potassium also helps strengthen the marijuana plant’s immune system, which helps the plant cope with environmental stresses, including insects and diseases. Bloom formulated fertilizers often include increased levels of potassium because it helps improve flower quality.

  • Found in both ‘Grow’ and ‘Bloom’ fertilizers
  • Helps plants immune system
  • Increases flower quality

Information taken from marijuana growers hq


New Member
good read


New Member
lol great read indeed took me a while to get through because there is sooo much info to absorb its crazy!


New Member
Im just finding more and more info!! Here is some explained from a fellow 420er who talks about HOW the plants use rhe nutes u give them hahaha thought it was a GREAT read so thought i would share!
Here is a simplified overview of nutrient functions:

Nitrogen is needed to build chlorophyll, amino acids, and proteins. Phosphorus is necessary for photosynthesis and other growth processes. Potassium is utilized to form sugar and starch and to activate enzymes. Magnesium also plays a role in activating enzymes and is part of chlorophyll. Calcium is used during cell growth and division and is part of the cell wall. Sulfur is part of amino acids and proteins.

Plants also require trace elements, which include boron, chlorine, copper, iron, manganese, sodium, zinc, molybdenum, nickel, cobalt, and silicon.

Copper, iron, and manganese are used in photosynthesis. Molybdenum, nickel, and cobalt are necessary for the movement of nitrogen in the plant. Boron is important for reproduction, while chlorine stimulates root growth and development. Sodium benefits the movement of water within the plant and zinc is neeeded for enzymes and used in auxins (organic plant hormones). Finally, silicon helps to build tough cell walls for better heat and drought tolerance.

You can get an idea from this how closely all the essential elements are involved in the many metabolic processes within the plant, often relying on each other.

Nutrient movement and mobility inside the plant:

Besides endocytosis, there are two major pathways inside the plant, the xylem and the phloem. When water and minerals are absorbed by plant roots, these substances must be transported up to the plant's stems and leaves for photosynthesis and further metabolic processes. This upward transport happens in the xylem. While the xylem is able to transport organic compounds, the phloem is much more adapted to do so.

The organic compounds thus originating in the leaves have to be moved throughout the plant, upwards and downwards, to where they are needed. This transport happens in the phloem. Compounds that are moving through the phloem are mostly:
Sugars as sugary saps, organic nitrogen compounds (amino acids and amides, ureides and legumes), hormones and proteins.

Not all nutrient compounds are moveable within the plant.

1) N, P, K, Mg and S are considered mobile: they can move up and down the plant in both xylem and phloem.
Deficiency appears on old leaves first.

2) Ca, Fe, Zn, Mo, B, Cu, Mn are considered immobile: they only move up the plant in the xylem.


New Member
Serious stuff..Thanks!
Top Bottom