In the beginning, all 6-year-old mystro had of his own creation was a tree fort to escape my two sister’s bullshit. I built it high up in an avocado tree on my family farm with sticks, branches and vines. My parents realized my creativity very young. Sitting alone up in that big tree surrounded by rotten green landmines gave me certain early perspectives on nature. Life and death. Don’t fall. Like this avocado tree is a far better platform to build on than those fuckin’ mango or citrus trees. Mango sap is no joke. But citrus tastes way better than that green mush. Better is a matter of perspective and application. I was thinking about plant structure back then just like I do today. Out there, I never met a snake I didn’t want to catch or a rotten fruit I couldn’t throw accurately at my sister when she brought her Care Bears too close to the fort. My parents encouraged me to catch snakes, do art and plant trees young. Plants represented work to me so it wasn’t love at first sight. I started learning about and growing plants when I was 8 years old. I wanted money so I had to go to work. At 15 that work became a passion when I saw my first cannabis plants. Nothing but love for the workers who tossed those seeds for me to find while out looking for snakes to catch, I snatched a few. 😉 Growing cannabis has taught me discipline, patience, a greater attention to detail and a respect for time. It takes time to get through crop cycles. Is a grower who staggered 20 crops in 2 years indoors as experienced as a grower with one outdoor crop a year for 20 years? 35 years of growing plants has also taught me a lot about myself and my place in the universe. You’re grow may not finish perfectly but that doesn’t mean you shouldn’t start with perfect intentions and work from there. Ego and doubt has ruined many crops. Forcing myself to be humble around my cannabis plants has opened up my soul to learning the universe’s true intentions. Which I’ve learned is to find balance between forces. I’m not trying to get sucked in or ripped apart. I hope everyone who read’s my ramblings finds at least one thing of benefit to them but, reading and learning are irreverent to the universe without doing. Your plants will tell you everything you need to know about their happiness or sadness if you’re paying attention. Here’s my perspective on cannabis nutrition after almost 30 years of experimentation.
Atoms, Molecules and Electronegativity:
Cannabis nutrition begins and ends on the periodic table, so I’ll start there. Well, there is one thing plants use not on the periodic table. Photons. Pure energy with no mass. There are 21 elements cannabis can use that have mass. 17 are essential elements plants require and 4 beneficial elements plants don’t require. Plants can also uptake minerals of no benefit. 18 of the elements are inorganic mineral ions and 3 (carbon, oxygen and hydrogen) are non minerals taken up as a gas, water or attached to a mineral by a bond. Plant nutrition is atomic. When atom’s become ions with a charge, their ionic charge is known as an oxidation state, which is also the magnitude of an ion’s or molecule’s charge. An element’s oxidation state is changed when electrons are given up or taken on. Stick with me. It’ll all make sense. This is known as a redox reaction. It’s short for the reduction (reduce charge) – oxidation (gain in charge) process. Reduction is when a molecule gains electrons and oxidation is when a molecule loses electrons during a bond. All atoms have an equal number of electrons and protons and are neutral. Atoms become ions with a charge when they gain or lose electrons. Electrons want to be in pairs (stable) and electronegativity is how we measure an atom’s ability to attract bonding pairs of electrons. When atoms share electrons on their outer shell aka their valence shell or ring, they form a covalent bond. Balance in the force. This is a permanent bond between atoms that creates molecules. Another type of bond is called an ionic bond. Not to be confused. We don’t typically want ionic bonds but they are not permanent bonds and can be broken. Microbes can break these bonds with enzymes in their gut.
Plants have no direct use for the solids ionic bonds create. Ionic bonds occur when 2 oppositely charged molecules bond and become unavailable to the plant. Like when positively charged calcium ions and negatively charged phosphate ions bond to become an unavailable solid calcium phosphate. Same happens with sulfate. Sulfate and phosphate attract positively charged metal ions. When carbon, oxygen and hydrogen are a gas or water they have no formal charge and are neutral. Once oxygen or hydrogen attaches to a mineral like nitrogen or phosphorus through a colvalent bond, the charge of the ion changes. Hydrogen has one electron and when it loses it’s electron in a covalent bond, it becomes a positive ion (H+). Oxygen has six valence electrons and wants eight. When oxygen gains two electrons in a covalent bond, an oxide ion is created (O 2-). Plants adsorb these 18 elements through inorganic ion exchange transport mechanisms. Active transport systems via the roots, exchange ions during the day. 16 of these 18 minerals have either a negative (anion) or positive (cation) charge. Cations are considered metal ions and anions are considered non metal ions. Yes, calcium and magnesium are considered metal ions. Anions play an important role in the physical opening of leaf stomata. Two of the 18 minerals actually have no charge. One mineral plants need (boron) and one mineral plants can use (silicon) have no charge and are neutral. They start no static and are chill as fuck. Nitrogen is the only element plants uptake that can be part of an anion or cation depending on whether it’s attached to hydrogen or oxygen. In either instance, their charge is fairly weak and we don’t have to worry about nitrogen forming solids through ionic bonds. Kind of a double edged sword though since nitrogen especially in the form of nitrate is so easily leached from substrates. While ammonium will compete with other cations for space on a particle possibly causing another cation to be less available. Carbon is neutral and can enter the plant through the leaves and roots but when carbon enters the plant through the roots, it comes in the form of organic molecules like acids and carbohydrates and not part of a cation or anion.
The essential elements are hydrogen, oxygen, carbon, nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, chlorine, iron, manganese, zinc, copper, molybdenum and nickel. Beneficial but not required elements are silicon, sodium, cobalt and selenium. Chromium, titanium and vanadium have been debated as possible beneficial elements but no proof exists. Plants can also uptake metal elements that are toxic like lead and aluminium. Roots actually have primarily a slight negative charge that attracts metal cations like aluminum (Al +3) and slightly repels anions like phosphates and sulfates except at their special receptor sites. Toxic metals can take the spot of cations and anions if it has a similar charge. Organic matter’s surface area is mostly comprised of negatively charged spaces. Organic matter like peat, humus, coco and clay attract cations on their negatively charged surface. Clay particles are like flat sheets of paper that can fit a whole bunch of cations on the negatively charged surface while the edge has a positive charge with a much smaller area for anions to adhere. All the elements plants use are not randomly scattered across the periodic table. They’re actually clustered together in groups up top.
There’s a couple different ways to classify these elements. Like cations, anions and macro/micro nutrients based on charge and plant tissue concentrations. No matter the element, the law of minimums holds true. One element out of balance can severely limit plant growth regardless of other mineral’s availability. Macro and micro-elements are separated by their importance to the plant. Macro-elements are elements plants use in concentrations over 5 ppm in a solution and can be measured in parts per million while micro-elements are used in fractions of a percentage, better measured in parts per billion. The concentration and ratio of minerals changes depending on the stage of growth. I’ll go over each element’s biological functions and it’s plant available forms further down. Cannabis doesn’t uptake N and P alone like K. Nitrogen and phosphorus only come into the plant attached to hydrogen or oxygen. This is the only reason why I mentioned covalent bonds before. They are relevant to how our plants consume two of the most important elements for growing roots, leaves, stems, and of course the dank buds.
Macro-Elements: Hydrogen, Oxygen, Carbon, Nitrate, Potassium, Calcium, Phosphate, Ammonium, Magnesium, Sulfate, Silicic Acid and Sodium,
Micro-Elements: Chloride, Boric Acid, Iron, Manganese, Copper, Zinc, Nickel, Molybdate, Selenate and Cobalt.
Metal Cations: Potassium, Calcium, Ammonium, Magnesium, Sodium, Iron, Manganese, Copper, Zinc, Nickel and Cobalt.
Non-Metal Anions: Nitrate, Hydrogen Phosphate, Dihydrogen Phosphate, Sulfate, Chloride, *Molybdate and Selenate.
*Molybdate is technically a metal oxyanion with four oxygen atoms covalently bonded to the central molybdenum atom that takes a negative charge because of the oxygen atoms.
Neutral: Boric Acid and Silicic Acid.
Cation and anion exchange happens when a similarly charged ion, possibly with a stronger charge, replaces that ion. For instance, when a hydrogen ion H+ is attached at a root’s negatively charged receptor site, it can be exchanged with a stronger cation like Ca 2+ that then can move across the active transport chain eventually becoming part of cell walls. That hydrogen ion exchange/release is how cation exchange lowers pH.
You gotta get the nutes to the roots to grow fruits as stated by Dr. J 303 PhD. Roots give the plant an anchor to a substrate while providing minerals, organic acids and water to the plant. They are mainly comprised of cellulose. The outer most cell layer of roots, stems, leaves, bud and seed is called the epidermis (surface) layer which is basically the protective cell layer. Cation and anion exchange happens on the root hairs that form out of this cell layer. Root hairs are a type of elongated tube like epidermal cell called trichoblasts. If I need these tric’s to get the other trics, is that trics on trics bro? Probably. They are full of mitochondria (where respiration and energy production occur) that provide the metabolic energy required for active ion transport. Along the length of the trichoblast is where the mineral ion exchange happens. Past the epidermis layer are parenchyma (per-rank-a-ma) cells. They are bigger than epidermal cells with thin cell walls that have gaps or channels between them that can store sugars and let water, minerals and organic molecules like fulvic acids pass around and through them. These channels between the cells are known as plasmodesmata and connect cells together for transportation of water/ions or communication between cells. Once through the parenchyma cells, water and ions reach the endodermis (endo means inside) cell layer that’s covered by a thin waxy layer called the casparian strip that regulates water, carbohydrate and ion flow farther inside the root. The area past the epidermis cells from the parenchyma to the endodermis is called the cortex. The next layer of cells past the cortex are called pericycle cells. Pericycle cells are fuckin’ badass because when they divide, they create the lateral roots allowing them to spread out and conquer the substrate. Once past the pericycle cells you reach the inner vascular cylinder. The vascular cylinder contains xylem and phloem tubes and they are the plant’s plumbing. The area of cells from the pericycle to the phloem tubes is called the stele. Xylem tubes transport water and ions up the plant from roots to stems and leaves during the day for photosynthesis to create sugars out of the carbon, hydrogen and oxygen and the phloem tubes transport the sap created (carbs, sugars and water) down the plant to the leaves, stems, buds and roots. Vapor pressure deficit (VPD) on the leave’s stomata isn’t the only thing aiding plant transpiration and respiration. You may be up on VPD but are you down with RPB? Root pressure bro. I hope that root pressure is down this afternoon. During the day, hopefully it’s low and at night it’s higher. During the day, the root’s cell membranes absorb water through the cytoplasm by osmosis created by a lack of root pressure. At night, root pressure occurs in the xylem when the moisture level in the rhizosphere is high and transpiration is low. When transpiration is high during the day, water and ions are hopefully under tension from transpirational pull, lowering root pressure. When root pressure is too high plants can’t drink or don’t drink. So there’s no point irrigating hydro at night.
Potential of Hydrogen, Nutrient Availability and Mobility:
The potential or power of hydrogen is based on the concentration of hydrogen ions in a solution. The higher the concentration of hydrogen ions, the lower the pH and acidity. When hydrogen ions are used up, the pH and alkalinity rises. Acids start at a pH below 0, neutral is 7 and above 7 is alkaline. A 1 point change in pH is equal to a 10-fold increase or decrease in the amount of hydrogen ions in the solution. Citric acid, phosphoric acid and dehydrated fulvic acids are great at lowering a solutions pH while I like sodium bicarbonate (NaHCO3 baking soda) as pH up in hydroponics. Calcium sources in a soil are alkaline and buffer the soil from going too acidic. pH affect’s the availability and adsorption of nutrients by the roots. Minerals lose their solubility in different pH ranges based on their interactions with hydrogen and oxygen ions. An alkaline pH higher than 7 can cause boron, copper, iron, manganese, and zinc ions to be less soluble. All trace elements lose some solubility above 6.5 with molybdenum being the exception. Not a pH for gardening anyways. Below 6 can cause the solubility of calcium, magnesium and phosphates to increase. We all know between a pH of 5.5 and 6.5 is perfect for our plants. Some elements are soluble in very acidic solutions while other elements are soluble in very alkaline solutions. To make sure they are all available, we want a happy medium between acidic and alkaline. We never want a static pH though. You’ll want it to fluctuate so all the essential minerals get adsorbed. As mentioned above, the mineral ratios and concentrations change weekly in veg and almost daily in flower. Your bloom booster will do you no good if your substrates pH is 6.5. In veg, ammonium and nitrate uptake is crucial. Special bacteria prefer a pH above 6 to convert NH4 to NO3. I’ll go more into the nitrogen cycle later. Minerals can precipitate or fall out of solution because of pH. Some may be heavy enough to fall as sediment or even light enough to stay suspended yet still unavailable. Cation and anion exchanges also play a role in the pH of the rhizosphere or hydroponic nutrient solutions. Cation exchanges release hydrogen ions lowering pH. Anion exchange uses hydrogen ions causing a raise in pH. During the day, the process of photosynthesis also releases hydrogen ions when electrons are being passed in a series of redox reactions in an electron transport chain across cells. At night when photosynthesis stops, plants and microbes increase their rate of respiration which consumes hydrogen ions causing a rise in pH. This is one way those microbes in Recharge help regulate pH. If a plant becomes mineral deficient, it has the ability to trans-locate some minerals from one part of the plant to another back up the phloem. Typically pulling minerals from the lower leaves up to the new growth up top. About half of the minerals are semi-mobile. They’ll initially be moved up the plant from the roots and become immobile once they get where they’re going. Calcium is part of cell walls and you can’t remove a house’s framing and have it still stand. If any of these elements become deficient, necrotic, stunted and damaged leaves start to appear. Notice it’s mainly macros that are mobile and mainly micros being semi-mobile. Molybdenum is the only mobile micro element.
N, P, K, Mg, Cl, Mo, Na
Ca, S, B, Fe, Cu, Mn, Ni, Zn, Co
Organic Molecules and Bio-Stimulants:
No cations or anions here. Yet. Organic substances require a process of mineralization to become plant available inorganic ions. Calcium carbonate (CaCO3) is a solid rock. For the calcium to become available to plants it needs to have the carbonate (CO3) removed. It comes from many sources in nature like sea shells and egg shells. It comes in the form of calcite and aragonite. Mix calcite and aragonite and you got limestone. Rain can bring trace amounts of minerals into soils too. When CO2 from the atmosphere mixes with water like rain, carbonic acid is formed. That carbonic acid will then interact with calcium carbonate creating soluble calcium bicarbonate. This is how caves are carved. Compounds with a carbon bond like amino acids, other organic acids, proteins, lipids (fatty acids) and sugars are all part of a healthy rhizosphere. Roots feed microbes exudates made during photosynthesis of carbon rich sugary sap and microbes feed plants minerals and other organic molecules in return.
Humic and fulvic acids are organic chelators (claws) that grab a bunch of trace minerals so that nothing in the substrate can dislodge them like sulfates and phosphates, but weak enough to be released to the roots. Humic and fulvic acids can break ionic bonds like calcium phosphate (CaPO4). Even minerals attached to carbon like the calcium bicarbonate in our water. Humic acids are too large of a molecule to penetrate the root cell walls or slip in through the cracks but fulvic acids are small enough molecules to slip right in. Great for foliar applications too. Humic acids lock up cations and store them in the rhizosphere for ion exchange so phosphates and sulfates don’t create ionic bonds. Fulvic acids do the same but have the ability to carry these micro-nutrients directly into the cells. This saves the plant a whole bunch of energy by not completely relying on cation exchange. Fulvic acids can skip right past the line to the trichoblasts and enter anywhere it finds an opening on the root. Humic and even fulvic acids are made up of combinations of hydrogen, oxygen, carbon, nitrogen and Sulfur. Carbon is only a common denominator between organic molecules and not the most abundant element in these molecules. That’s why I list it as the 3rd macro-element. You’ll notice oxygen and hydrogen find themselves in fuckin’ everything, not just organic molecules.
We’ve all probably heard that amino acids are the building blocks of life. They are, but what builds them? These are the kinda thoughts that would run through my head sitting and smoking blunts in the grow. The nitrogen cycle plays an important role in their creation actually. When amino acids bond through covalent bonds called peptide bonds, they create the proteins that build plant tissue. Grow my buds bigger bitch. Amino acids consist of 3 functional groups that make up the molecules structure. Aminos have amine (-NH2 nitrogen and hydrogen) and carboxyl (-COOH carbon, oxygen and hydrogen) functional groups with the third group being a different side chain or R group that makes each amino acid molecule unique. Amino acids can act as chemical messengers sending signals between cells too. 22 amino acids have been discovered with about half being essential. Some are created inside the plant like we have in our bodies. Bacteria and fungi along with all the other life in healthy soils create a diverse ecosystem capable of providing plants with all the necessary requirements for growth minus the photons. They poop acids and enzymes which are a type of protein and bio-catalysts that speed up chemical reactions in cells like during respiration, photosynthesis and making new proteins. Enzymes and phytohormones help cannabis plants spend less energy when starting a function. Amino acids are precursors of phytohormones like auxins, one of the the main groups of plant hormones for root growth. Plant growth regulators (PGR’s) are phytohormones and signaling molecules like enzymes that send signals to produce this or that or break down this or that. Certain enzymes can also act as place holders. Holding something so it can’t get away. Cellulase is a class of enzymes outside the plant responsible for the break down of cellulose. Turning old roots into microbe food. Enzymes called nitrate and nitrite reductase in the plant convert nitrogen into it’s different forms along the nitrogen cycle. In the plant, enzymes start the conversion of various plant hormones. The essential fatty acids omega-3 (alpha-linolenic acid) and omega-6 fats (linoleic acid) are only created by plants. Animals can’t produce them. The omega-3 we get from fish comes from the plants they eat like algae. Vitamins benefit the plant too. Vitamins B, C and E have shown small benefits to plant growth. Vitamin B can aid in root formation, vitamin C can aid in photosynthesis by protecting against a free radical like ozone (O3) and vitamin E helps the plant’s metabolism produce more energy in colder than ideal temps.
Bacteria and fungi both fall into the category of microbes. These microbes play the most significant role in organic plant nutrition. The food web starts with much larger organisms but they don’t form a direct symbiotic relationship with cannabis’ roots. Don’t jump on a shark and have Jaws bite your ass by using the wrong microbes. Not all fungi are of benefit to cannabis plants. Mycorrhizal fungi form symbiotic relationships directly with roots. There are endo and ectomycorrhizal fungi, endo penetrate the roots while the ecto grow only on the surface. Only endomycorrhizal fungi form a relationship with cannabis. Any product with ectomycorrhizal fungi in it won’t work with cannabis. A Mycorrhiza fungus or Mycorrhizal fungi only become mycorrhizae after the fungus/root relationship has been established when it’s part fungus, part root. When they penetrate/pass around the root’s epidermis cells so they can help bring in more water and minerals. Anion exchange like with phosphates and sulfates becomes much easier with the extra surface area and structure. The plant sends chemical signals to the fungi and bacteria to colonize and solubilize minerals it wants at that specific time and place.
Glomus species of mycorrhizal fungi are what’s in Recharge. Glomus aggregatum, Glomus mosseae, Rhizophagus irregularis (formerly Glomus intraradices) and Glomus etunicatum. Not only do they provide structure, protection, water and minerals, glomus species help build proteins responsible for cell division by lowering the amount of chromosomes needed by half. Fuck ya, fun guys. Mycelium, are the vegetative branching on fungi that form thin hair like filaments called hyphae. That’s the webbing you can see up on the soil surface decomposing leaves and other organic matter.
Another type of beneficial fungi in Recharge don’t form a direct symbiotic relationship with the roots called trichoderma. These fungi are natures industrial decomposers. They can chew down coconut fiber’s cellulose to the ligin very fast. Trichoderma reesei and harzianum in Recharge are great at what they do. Trichoderma harzianum are brutes. They’ll fight any pathogenic fungi that try to step up in the rhizosphere or leaves. Botrytis and Fusarium don’t stand a chance when used. Trichoderma reesei is a major composter. It breaks cellulose down to it’s simple sugar glucose for other microbes like bacteria to consume fast.
Trichoderma reesei are capable of producing cellulase, an enzyme that converts cellulose into glucose sugar. Fungal colonies can be massive but bacteria are tiny. Bacteria are some of natures smallest mineral storage totes. They love to eat simple sugars like the glucose from the cellulose fungi are decomposing and at the same time consuming minerals too. They make a great team.
Bacillus licheniformis, pumilus, subtilis and megaterium found in Recharge are decomposers, organic acid, protein and enzyme producers as well as mobile mineral storage. Bacteria love sugar and the sugar sticks to even ionic bonded solids like calcium bicarbonate or calcium phosphate. Once those solids are in the bacteria, they are enzymatically separated and pooped out as usable ions. Carbon based bio-stimulants are the difference between a low brix plant and a high brix plant. Brix is a measure of glucose in plant tissue and a measure of how much sugar is being created through photosynthesis. Bio-stimulants act as catalysts, providing the energy needed to start metabolic functions. These organisms do all of natures chemistry. Little scientists. Synthetic only hydroponics deliver inorganic minerals in a solution that can provide for a plant’s basic needs but doesn’t have the extra energy to really push secondary metabolites like cannabinoids, flavonoids, terpenes and other botanical oils that have no bearing on the plant’s survival.
Temperature and humidity:
In order for your cannabis plants to maximize their potential, their environmental conditions need to be in optimal ranges at all times for them to efficiently consume light and food. Temperature has an effect on transpiration and the amount of water and minerals the plant can consume. Water temperature plays a role in the amount of oxygen a solution can hold. This affect’s pH and mineral solubility. Air temperature regulates the amount of moisture the air can hold which affects humidity. Humidity or vapor pressure helps regulate stomata during gas exchanges. These variables will change depending on the stage of growth. Too hot and cannabis will spend a bunch of energy just trying to keep cool. Too cold and they don’t want to work. They’re just sittin’ in the back smoking a blunt on break. During the vegetative cycle, daytime leaf surface temperatures between 82 F – 86 F with a relative humidity between 60% – 70% seem to work the best with most hybrids with night temps and humidity around a 5 – 10% diff in either direction for optimum growth. The diff is a measure of the difference between night and day temps and humidity. Pure land races can usually withstand environments way harsher than our indoor hybrids depending on the climate they evolved in. Equatorials may prefer hot and humid rooms while a broad leaf from the cold, windy mountains can handle some cold, dry air. In flower, temperature and humidity affect growth but they also have an effect on resin. Daytime leaf surface temps between 78 F – 85 F with a relative humidity between 45% – 55% with a night and day diff of about 5% I find work best. Too hot of a room or lights can stimulate and release terpenes. Some terpenes act as solvents and also react with cannabinoids and other essential oils in the trichome over time. This is why trichomes turn amber. Heat speeds up the process and cold slows it down. Cannabis doesn’t seem to produce as many trichomes in humid environments so I keep my flower rooms humidity in check at all times during flower.
Photosynthesis, Respiration and Transpiration:
Chloroplast Where Photosynthesis Occurs
Not all energy plants need enters from the roots. Some things come in through the leaves like carbon, oxygen and photons. I count photons as plant food too. Photosynthesis has two mechanisms for collecting these photons called photosystems I and II that create different chlorophyll proteins. The green pigment in plants is called chlorophyll that’s located in what’s called chloroplasts. Chloroplasts are the part of plant cells where photosynthesis occurs. Chlorophyll is made of oxygen, carbon, nitrogen, hydrogen and magnesium and turns photon energy into chemical energy required for growing dank. There are many different types of chlorophyll. Cannabis Plants use chlorophyll a to absorb wavelengths from the violet through blue wavelengths and the red wavelengths. Accessory pigments chlorophyll b, xanthophylls, and carotenoids absorb colors like green, yellow and orange wavelengths. Chlorophyll has a soluble hydrocarbon tail, a flat head with a magnesium ion core with a unique side group to each one. Just like amino acids have unique side groups. I won’t bore you with all the details involved in this complicated as fuck process. During the day, these chlorophyll containing chloroplasts in the surface cells of leaves absorb photons in different wavelengths or spectrum for the energy required to make Adenosine triphosphate (ATP). During cellular respiration, glucose is torn apart and the energy that’s created produces ATP which basically is the fuel that drives the energy transfer. Like gas for a car. Carbon dioxide is brought in through the stomata on the leave’s surface and water and ions from the roots up through the xylem to create glucose sugar, other carbohydrates and organic acids that are then sent back down the plant through the phloem providing the plant with nutrition as well as exudates out of the roots to feed microbes. The equation for photosynthesis is simple but the process is not. It takes six carbon dioxide molecules plus twelve water molecules plus about 48 photons to create one molecule of glucose sugar (C6H12O6), with six molecules of O2 gas left over to be sent out the stomata (6 CO2 + 12 H2O + photons = C6H12O6 + 6 O2). I told you hydrogen and oxygen was in everything.
Plant nutrition mixes light with water and minerals to create organic molecules. Plant respiration is an aerobic chemical reaction that happens when glucose is made and oxygen is released. The amount of light plants receive directly affects not only photosynthesis but respiration as well because they are opposites. If photosynthesis uses carbon dioxide and produces oxygen, then respiration uses oxygen and produces carbon dioxide. At night with no light, respiration is high with cells taking in oxygen and releasing carbon dioxide. Respiration occurs day and night while photosynthesis is a day time thing. In low light, a balance can be achieved where no gas is taken in or out. During mid day, photosynthesis far out paces respiration and this is how the plant consumes carbon dioxide and release oxygen.
Transpiration is the flow of nutrients that allows for photosynthesis and respiration. The xylem and phloem tubes located in the vascular tissue are the transportation highways these nutrients flow through. The xylem tubes are hollow and only flow one way, up. The phloem tubes have partitions along the tube that allow sap to flow in both directions. Cannabis leaves and stems have epidermal cells called stoma. These stomata are the plant’s gas exchange ports. Carbon dioxide and oxygen’s in and out sites.
Vapor pressure deficit (VPD) is the measure of force put on stomata by water vapor in the air allowing for the transpirational pull of water and ions and root pressure is a measure of force put on roots. Both of these forces contribute to the flow of nutrients through the plant. The more pressure put on stomata and roots, the less transpirational pull and vice versa. Water, in the air and rhizosphere control flow up the xylem. This is where a grower can sacrifice quality for quantity. A perfect VPD may increase the plant’s bio-mass but the high humidity negatively affects the plant’s secondary metabolites in flower by decreasing resin production. Flowering plants hate high humidity unlike other plants that don’t produce surface trichomes. Balance here is a razor’s edge. Transpiration also plays another role other than moving nutrients and water. Water is also used as evaporative cooling and the only means cannabis has to regulate it’s internal and external temperatures. Less than 5% of the water cannabis absorbs is kept in the plant. The rest is transpired out through stomata, raising our grow room humidity.
Being an artist, I find it easier to absorb information when its represented visually through a graphic. So I made this chart so everyone can get a visual mineral representation. Each form of molecule, it’s charge and concentration are shown below.
Elements are listed in order of needed availability. moving from left to right, starting at the top row down to the bottom row. Starting with nitrate and ending with cobalt.
Mineral Concentrations and Ratios:
Cannabis’ nutritional needs doesn’t require the elements in the same concentration and ratio through it’s entire life cycle. It does require all the elements, all the time. A shift in the macro element ratios in comparison to each other will drastically change from start to finish while the micro element’s concentrations and ratios will not really change. Most of them are just required by enzymes and not as part of plant tissues. Every plant is an individual with individual needs but, there are some general guidelines to start with. I’ll explain what each element’s role is and the normal concentrations of each, in ppm, below. Through it’s life, as it matures from a young vegetative seedling or clone to growing giant trichome covered colas, cannabis goes through some pretty drastic changes. Her flowers are not really flowers like a hibiscus flower. She evolved long before actual flowers were even a thing. Her calyx (buds) mutated from leaves way way back when. As she goes through these morphological changes in flower, her macro nutrient ratios and concentrations change from a heavy nitrogen leaning diet in veg to a heavy phosphorus leaning diet during peak flowering. The ratio of nitrogen and phosphorus practically flips from veg to peak flowering. Potassium should almost always be as plentiful as nitrogen in veg and phosphorus in flower. In veg a plant might use as much potassium as nitrate but not in flower where potassium ratios are fairly on par with phosphorus. Nitrogen’s role decreases in the plant as it shifts into producing calyx. Too much nitrogen during flower will stunt calyx formation and grow a leafy fuckin’ bud. Leaf and bud are not the same and do not taste the same, no matter how many trichomes there are. A coco specific nutrient will just have lower levels of potassium because coco releases a bunch of potassium and sodium as it breaks down. That’s it, no voodoo science there. I’m looking to grow high calyx to leaf ratio buds. Leaf don’t weight shit anyways.
The other essential macro elements will stay in the same relative ratios throughout the cycle. All mineral concentrations in ppm are much lower early on in veg. Calcium, magnesium and sulfate are all very import to the formation of cells. Calcium in the cell walls for structure, magnesium also in the cells but for the formation of chloroplasts that take in the light, and sulfate as part of amino acids that build all the tissues. Near the end of her life she’ll require no minerals from the roots. She’ll have enough minerals stored in the bio-mass that can be trans-located where it’s needed. Most of her large fan leaves will be consumed at least a week before she’s done. With no need to produce any new growth like stem and leaves, she can use up the last of her mineral storage to swell her calyx. Growing big buds starts when she’s initially forming brackets of calyx looking for pollen. By the time she’s ready to use up her last reserves, she has no need for additional nutrition from her roots. Force a plant to hydroponically exchange ions this late in the game fucks with her hormones that can really fuck with her finishing. Putting food in her this late doesn’t give her time to consume it and you end up smoking that snap, crackle and pop. In a natural cycle, when cannabis has no more need for minerals, she’ll start to consume herself. When those large leaves drop, photosynthesis slows way down. No photosynthesis, no sugar to feed microbes. The microbes stop providing minerals in return. Naturally flushing the plant of excess minerals. Time to dry the plant matter, then cure the soft waxy membrane protecting the essential oils to a hard shell, then smoke that bitch.
Biological Functions Of The Elements and A Particle:
Not an element but a mass-less particle. A photon’s energy is based on the wave it’s traveling on. Short, high frequency, waves have more energy than longer, low frequency waves. These electromagnetic waves and frequencies range from gamma rays to radio waves and all the colors in between we call visible light. Spectrum is a popular way to describe these waves. Cannabis absorbs the violet through blue and red wavelengths with chlorophyll a and the other colors green, yellow and orange through chlorophyll b, xanthophylls, and carotenoids. The visible spectrum starts about 400 nanometers (Ultraviolet UV) and goes through about 700 nanometers (Infrared IR). The Spectrums plants absorb can also be classified by photosynthetic active radiation or PAR. In the early 1970’s Dr. Keith McCree wrote a paper about how plant’s respond to light. Here’s a link.
Hydrogen: Hydrogen Ion (H+)
Hydrogen makes up almost 80% of not only our atmosphere but the universe as well. Hydrogen’s role in plants seems to be part of most processes as it’s abundance would suggest. Hydrogen ion’s (H+) availability in water creates an acidic or alkaline solution. It’s taken up through the roots as water, part of an inorganic mineral or organic molecule like fulvic acids before being used inside the plant to create other organic molecules like amino acids, proteins/enzymes and a bunch of other organic substances like glucose. Hydrogen ions (H+) in relation to oxygen ions (O 2-) change a molecules redox state towards the positive.
Oxygen: Oxide Ion (O 2-)
Like hydrogen, oxygen seems to be attached to a lot things and processes. Oxygen is used during and is also a waste product of photosynthesis. Oxygen is consumed during respiration. It only makes up a little more than 20% of the earths atmosphere but it’s just as important as hydrogen. Plants use or produce oxygen as an oxide ion or attached to other molecules like water and carbon dioxide to minerals like nitrates and phosphates. If a plant doesn’t have any light but still needs energy, it can burn glucose for that energy but uses up oxygen in the process. Each oxide ion brings a negative two charge towards a molecule’s oxidation state. Oxygen is a major component inorganic molecules and organic molecules like glucose sugar. Two of the most important molecules CO2 and H2O have oxygen in common.
Carbon: C Neutral
Carbon is the one element that’s ultimately responsible for life. Silicon is another suitable candidate from which life could possibly evolve. Carbon enters the plant as a gas attached to oxygen CO2 or as part of organic molecules like acids, carbohydrates, proteins and lipids. The carbon based sugars drive most of the plants energy along with oxygen and hydrogen. Carbon, hydrogen and oxygen ratios control most of the plant’s growth. They require balance between them.
Nitrogen: Essential Anion Nitrate NO3 – or Cation Ammonium NH4 +
Nitrogen’s pH Solubility Range: Nitrate: 6.0-7.5 and Ammonium: 4.0-6.5
Recommended Hydroponic Usage Rates: 100 – 400 ppm
Nitrogen first of all never comes into the plant as just N. It’s role in the biological functions of the plant are not to be understated. Nitrogen isn’t just fertilizer. It’s literally makes up part the RNA/DNA of the plant. Nitrogen is part of a functional group called an amine (-NH2), a derivative of ammonia (NH3) that makes up part of all amino acids. Amino comes from ammonia. A metal cation like copper require amines for transport in the xylem & phloem. Nitrogen is in the heme group of chlorophyll and is why we associate the plant’s green color to nitrogen. Hormones like cytokinin divide cells with the aid of nitrogen. So as you can see, nitrogen is much more than just a fertilizer. But as a fertilizer, nitrogen is available to roots in two forms, as ammonium (NH4+) or nitrate (NO3 –). The nitrogen cycle is enzymatic. Cannabis doesn’t use ammonium or nitrate directly, and must use enzymes in the roots, stems or leaves to covert/reduce the different forms of nitrogen within the plant. I hope some of this chemistry is starting to make sense.
A special class of enzymes called nitrate and nitrite reductase does the nitrate, nitrite and ammonium conversions. Reduction to nitrite (NO2 –) doesn’t just happen as nitrate enters the plant through the roots. Reduction can happen in the xylem tube on the way up the plant and even in the leaves. Highly specialized bacteria form relationships with nitrogen fixing plants like clovers, that can pull N2 from the atmosphere, an incredible strong and stable bond, and shit out ammonium. I wish we could get them to colonize cannabis roots. Ammonium conversions consumes more oxygen than nitrate conversions. So it only makes sense that low water temps are more favorable to ammonium reduction. Nitrates can stay soluble in higher temps so it would make sense that desert plants prefer nitrates while wetland plants would prefer ammonium. Cannabis is a plant that can use both forms. Decomposing plants provide the bulk of nitrogen found in the soil, but nitrogen can come from other carbon sources like mammals and their urea CO(NH2)2. These guys (Haber and Bosch) found a way with heat and pressure to synthetically convert N2 from the atmosphere to ammonia NH3 for commercial fertilizer production. Nitrogen uptake affects the rhizosphere pH like I mentioned before. The charge on the root cells needs to be balanced. Ion exchange is a swap of the same charged ions at an active mineral transport site. Nitrogen attached to hydrogen (ammonium NH4 +) is a cation (positive) and releases a (positive) H+ ion in the exchange which lowers pH and increases the acidity. Nitrogen attached to oxygen (nitrate NO3 –) is an anion (negative) that consumes hydrogen ions during uptake, raising the pH. During nitrate uptake bicarbonate (HCO3 -) is released. See how hydrogen and carbon replaced the nitrogen. Another reason nitrate is preferred by cannabis growers is because ammonium is a cation that competes for space on soil/clay particles with other cations like potassium, calcium and magnesium. This is what nutrient antagonism is. Too much of one limits the space for others of the same charge to fit on the particle. Plants like ammonium because it just needs to go from NH4 + to NH3 to NH2 –. Where nitrate goes from NO3 – to NO2 – to NH4 + to NH3 to NH2 –. Problem with ammonium as opposed to nitrate, ammonium would take up space other cations need on substrate particles.
Potassium: Essential Cation K+
Potassium’s pH Solubility Range: 5.0-10
Recommended Hydroponic Usage Rates: 100 – 350 ppm
Potassium only has one stable oxidation state and is a cation that’s soluble at all pH ranges. It’s very stable. It’s not toxic at levels higher than required so it’s also forgiving. It’s very mobile in the Phloem and doesn’t bind to complexes or ion pairs in a soil or solution. It has a fairly weak charge and doesn’t interact with most ions. Potassium is a fairly friendly element to use in gardening. Potassium regulates CO2 absorption by controlling the stomata’s opening and closing. Potassium activates enzymes for the production of adenosine triphosphate (ATP). Osmosis, or the osmoregulation of water in plants is controlled by potassium. Sufficient potassium makes plants able to drink lots of water.
Phosphorus: Essential Anions Hydrogen Phosphate HPO4 2- or Dihydrogen Phosphate H2PO4 –
Phosphorus’ pH Solubility Range: H2PO4 –: 3.0-6.0 and HPO4 2-: 8.0-11
Recommended Hydroponic Usage Rates: 50 – 400 ppm
Like nitrogen, phosphorus doesn’t ever come into the plant as just P. The plant available forms of phosphorus come in the form of anion hydrogen phosphates. Hydrogen phosphate or dihydrogen phosphate depending on pH. The lower the pH, the more hydrogen ions are available to cause a redox reaction that changes the molecule. Phosphoric acid is H3PO4 which is one oxidation step away from H2PO4 – hydrogen diphosphate. If the pH rises, the lower amount of available hydrogen ions in a solution can convert hydrogen diphosphate to hydrogen phosphate HPO4 2-. Each time a phosphate molecule loses a hydrogen ion it becomes more negatively charged which can lead to ionic bonding with cations. Cannabis can uptake both H2PO4 – and HPO4 2- and their plant available form will depend on what the pH of the solution is. Phosphates really starts to lose solubility above a pH of 6. pH not only affects solubility but, also induces the creation of solids that are insoluble. At a very acidic pH, phosphate bonds with aluminum and iron to form solids while an alkaline pH higher than pH 7.5 will cause phosphate ions to bond with calcium and magnesium to also form solids. Some of phosphate’s biological functions in the plant are linked directly to the plant’s DNA and RNA as part nucleic acids. Phosphates help aid in ATP and ADP energy movement and storage. Can’t have adenosine triphosphate (ATP) without phosphate. Proteins made can be found throughout the plant as well as part of the chemistry that makes up cell membranes called phospholipids which are a type of fatty acid. This is all important because these are the functions that grow bud and roots.
Calcium: Essential Cation Ca 2+
Calcium’s pH Solubility Range: 6.0-7.5
Recommended Hydroponic Usage Rates: 80 – 200 ppm
Calcium’s an essential cation and it’s main function in plants is to provide structure to the cell walls of roots, stems, leaves and bud. There are small amounts of calcium needed in the cytoplasm that act as chemical signalers for stress being put on the plant by the environment.
Magnesium: Essential Cation Mg 2+
Magnesium’s pH Solubility Range: 6.0-9.0
Recommended Hydroponic Usage Rates: 50 – 100 ppm
Magnesium is a cation who’s central role in plant biology is as the center ion in chlorophyll molecules. Magnesium in the cytoplasm help activate enzymes and a little can also be found in the cell walls.
Sulfur: Essential Anion Sulfate SO4 2-
Sulfate’s pH Solubility Range: 5.0-10
Recommended Hydroponic Usage Rates: 30 – 80 ppm
The plant available form of sulfur is an anion called sulfate (SO4 2-). Sulfate makes up part of amino acids as co-enzymes or part of a functional group. Sulfur is part of the building blocks of life like carbon, hydrogen, oxygen and nitrogen. Sulfate helps aid the plant in chemical defenses by producing secondary metabolites like trichomes on the leaves and the signals sent to or from the roots of invaders.
Silicon: Beneficial Neutral Element Silicic Acid H4SiO4
Silicic Acid’s pH Solubility Range: 4.0-9.0
Recommended Hydroponic Usage Rates: 30 – 60 ppm
Silica is a beneficial neutral element that can strengthen cell walls and help fight off pests and environmental stresses. It can also stretch cell walls to allow for more chlorophyll in the cell. Silicic Acid H4SiO4 is the form the roots adsorb. Too much silica in solution loses solubility at low pH ranges. When silica creates bonds, it typically create’s a thick gel coating on every surface. Hydro pumps don’t last long when you use too much silica. Always mix silica to plain water first. It will react with the Ca and Mg in hard water too so be careful.
Sodium: Beneficial Cation Na+
Sodium’s pH Solubility Range: 7.0-10
Recommended Hydroponic Usage Rates: 30 – 60 ppm
Sodium is a beneficial cation plants can use to help sequester carbon dioxide that aids a little with the plant’s synthesis of chlorophyll. Sodium can act as a replacement for potassium that opens and closes stomata and acts very similar to potassium.
Chlorine: Essential Anion Chloride Cl–
Chloride’s pH Solubility Range: 4.0-10
Recommended Hydroponic Usage Rates: 2 – 5 ppm
Chlorine enters the plant as an essential anion called chloride Cl–. The role of chloride is in the opening/closing of stomatal guard cells. even rain contains chloride so deficiencies are rare. Sodium Chloride is table salt. Too much chloride has a dehydrating effect and can cause drought like symptoms in abundance.
Boron: Essential Neutral Element Boric Acid H3BO3
Boric Acid’s pH Solubility Range: 5.0-7.5
Recommended Hydroponic Usage Rates: 0.5 – 2 ppm
Boron is an essential neutral element that’s adsorbed by roots in the form of boric acid (H3BO3). Boron plays a major role in the plant’s metabolism even though it’s needed in very small amounts. It helps form cell walls and maintain the structural integrity of membranes along with calcium. Boron helps sugars move around the plant through the phloem helping to supply the energy during pollination and seed formation. All micro-elements, except molybdate, become less soluble as the solution or substrates’s pH rises above 6.5,
Iron: Essential Cation Fe 2+ or Fe 3+
Iron’s pH Solubility Range: 4.0-6.5
Recommended Hydroponic Usage Rates: about 1 ppm
Iron is an essential cation taken up in the plant as either Fe 2+ or Fe 3+. Fe 3+ has to be reduced in the plant to Fe 2+before becoming part of color pigments and a crucial role as part of enzymes. These are the same enzymes that assist in anion nitrate and sulfate reduction.
Manganese: Essential Cation Mg 2+
Manganese’s pH Solubility Range: 5.0-7.5
Recommended Hydroponic Usage Rates: 0.05 – 0.5 ppm
Manganese is an essential cation used primarily during photosynthesis in the photosystem II oxidizing system, A lack of manganese results in a decrease in soluble sugar concentrations around the plant because of a lack of photosynthesis. It’s part of over 35 enzymes that do all kinds of shit like catalyze lignin and phytoalexins to break down or synthesize.
Copper: Essential Cation Cu 2+
Copper’s pH Solubility Range: 5.0-7.0
Recommended Hydroponic Usage Rates: 0.05 – 0.5 ppm
Copper is an essential cation just like manganese in that it activates enzymes responsible for lignin synthesis and other enzyme systems. Copper too is required during the process of photosynthesis. Copper’s Essential for respiration and metabolic functions involving carbohydrates and proteins. Copper increases flavonoids and terpenes along with color pigments.
Zinc: Essential Cation Zn 2+
Zinc’s pH Solubility Range: 5.0-7.0
Recommended Hydroponic Usage Rates: 0.05 – 0.5 ppm
Zinc is an essential cation that makes up part of many enzymes and proteins like other trace metals. Life couldn’t exist without these enzymes and the metal they contain. You’ll often times find zinc added to cloning solutions because it also plays a important role with growth hormones and internodal elongation.
Nickel: Essential Cation Ni 2+
Nickel’s pH Solubility Range: 5.0-7.0
Recommended Hydroponic Usage Rates: 0.05 – 0.5 ppm
Nickel is another essential cation found in most water sources as a contaminant. It wasn’t thought to be an essential element for a long time because plants show noticeable deficiencies right away. You will not find it any most fertilizers. Like most metal cations, nickel is a part of many enzymes like urease that metabolize urea into usable ammonia. Nitrogen fixing cover crops use nickel in enzymes as a catalyst to convert nitrogen.
Molybdenum: Essential Anion Molybdate MoO4 2-
Molybdate’s pH Solubility Range: 6.5-10
Recommended Hydroponic Usage Rates: 0.01 – 0.20 ppm
Molybdenum is the last of the essential micro-elements. It’s taken up into the plant in the form of the anion molybdate (MoO4 2-). Molybdate is an essential part the two enzymes (nitrate and nitrite reductase) in the nitrogen cycle and many other enzymes. Molybdate is also part of turning inorganic phosphates into organic phosphates in the plant. Used in the tiniest of amounts, this metal is super important. It’s also the only micro-element that is highly mobile.
Selenium: Beneficial Anion SeO4 2-
Selenate’s pH Solubility Range: 7.0-10
Recommended Hydroponic Usage Rates: 0.01 – 0.20 ppm
Selenium is an essential element for animals but it’s not considered essential for plants, yet. It’s a beneficial anion adsorbed in the form of selenate (SeO4 2-). It’s essential to us, since plants are human’s only selenium source I know of. Selenate acts as an antioxidant aiding in immune responses and hormone metabolism. Selenium is chemically similar to sulfur and can compete with sulfates and molybdate interfering with their transport sites. Selenium helps keep stress low in plants by helping form sulfur and nitrogen molecules.
Cobalt: Beneficial Cation Co 2+
Cobalt’s pH Solubility Range: 4.0-7.0
Recommended Hydroponic Usage Rates: 0.01 – 0.20 ppm
Cobalt is a beneficial cation that just like most metals, help with the function and formation of enzymes. Cobalt’s also in Vitamin B12. B12 helps cell division like in the lateral root forming pericycle cells. Cobalt helps to create more cells requiring less energy from the plant’s metabolism. Cobalt can help with the absorption of carbon dioxide assisting in the plant’s overall growth of plant stems, roots, leaves and buds.
Well that it DGC. I started at the bottom of the rabbit hole and hopefully everyone made it out with a better understanding of their cannabis plants by The End. Growers Love.