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Nitrogen (N)- mobile
Practical Information: Marijuana loves nitrogen and requires high levels of it during vegetative growth but lower levels during the balance of life. Nitrogen washes away easily and must be replaced regularly, especially during vegetative growth. Excess levels of nitrogen in harvested plants cause the dried marijuana to burn poorly.
Technical Information: Nitrogen regulates the cannabis plant's ability to make proteins essential for new protoplasm in the cells. Electrically charged nitrogen allows the plant to tie proteins, hormones, chlorophyll, vitamins, and enzymes together. Nitrogen is essential for the production of amino acids, enzymes, nucleic acids, and chlorophyll and alkaloids. This important nutrient is mainly responsible for leaf and stem growth, as well as overall size and vigour. Nitrogen is most active in young buds, shoots, and leaves. Ammonium is the most readily available form of nitrogen. Be careful using too much of this form; it can burn the plants. Nitrate -the nitrate form of nitrogen- is much slower to assimilate then ammonium. Hydroponic fertilizers use slower-acting nitrogen compound and mix it with ammonium.
Deficiency: Nitrogen is the most common nutrient deficiency. The symptoms include slow growth. Lower leaves cannot produce cholorophyll and become yellow between the veins while the veins remain green. Yellowing progresses through the entire leaf, eventually causing it die and drop off. Stems and the leaves' underside may turn reddish-purple, but this can also be a sign of a phosphorus deficiency. Nitrogen is very mobile and it dissipates into the environment quickly. It must be added regularly to sustain fast-growing gardens.
Progression of deficiency symptoms:
- Older leaves yellow between the vein(interveinal chlorosis).
- Older bottom leaves turn entirely yellow.
- More and more leaves yellow. Severely affected leaves drop off.
- Leaves might develop reddish-purple stems and veins on leaf undersides.
- Progressively younger leaves develope interveinal chlorosis.
- All foliage yellows and the leaf drop is severe.
Treat deficiency by fertilizing with N or a complete N-P-K fertilizer. You should see results in 4 to 5 days. Fast-acting organic sources of nitrogen include: seabird guano, fish emulsion, and blood meal. Growers also report excellent results by adding bio-fertilizers to stimulate the uptake of nitrogen.
Toxicity: An overdose of nitrogen will cause excessively lush foliage that is soft and susceptible to stress, including insect and fungal attacks. The stems become weak and they may fold over easily. The vascular transport tissue break down, and water uptake is restricted. In severe cases, leaves turn a brownish-copper colour, dry, and fall off. Roots develop slowly, and they tend to darken and rot. Flowers are smaller and sparse. Ammonium toxicity is most common in acidic soils, while nitrate toxicity is more prevalant in alkaline soil.
Progression of toxicity symptoms:
- Excessively lush, green foliage.
- Weak stems that fold over.
- Slow root development.
- Flowers become wispy.
- Leaves brown, dry and fall off.
Treat toxicity by flushing the growing medium of the affected plants with a very mild, complete fertilizer. Severe problems require that more water be flushed through the growing medium to carry away the toxin elements. Flush a minimum of 3 times the volume of water for the volume of the growing medium. Do not add more fertilizer that contains nitrogen for one week so the excess nitrogen in foliage can be used. If the plants remain excessively green, cut back on the nitrogen dose.
Calcium (Ca)- immobile
Practical Information: Cannabis requires nearly as much calcium as other macronutrients. Avert deficiencies in the soil and in most soilless mixes by adding fine dolomite lime or using soluble-hydroponic fertilizers containing adequate calcium.
Technical Information: Calcium is fundamental to cell manufacturing and growth. Calcium is necessary to preserve membrane permeability and cell intergrity, which ensures proper flow of nitrogen and sugars. It stimulates enzymes that help build strong cells and root walls. Cannabis must have some calcium at the growing tip of each root.
Deficiency: Calcium deficiency is somewhat uncommon indoors, but is not uncommon in fibre hemp. Frequently, plants can process more calcium then is available. It also washes out of leaves that are sprayed with water. Deficiency signs may be difficult to detect. They start with weak stems, very dark green foliage, and exceptionally slow growth. Young leaves are affected, and they show signs first. Severe calcium deficiency causes new, growing shoots to develop yellowish to purple hues and to disfigure before shriveling up and dying; bud development is inhibited, the plants are stunted, and harvest is diminished. Growing tips could show signs of calcium deficiency if the humidity is maxed out. At 100% humidity, the stomata close, which stops the transpiration to protect the plant. The calcium that is transported by transpiration is immobile.
Treat deficiencies by dissolving one-half teaspoon of dehydrated lime per gallon of water. Water the deficient plants with calcium-dosed water as long as the symptoms persist. Or use a complete hydroponic nutrient that contains adequate calcium. Keep the pH of the growing medium stable.
Progression of deficiency:
- Slow growth and young leaves turn very dark green.
- New growing shoots discolour.
- New shoots contort, shrivel and die.
- Bud development slows dramatically.
Toxicity is difficult to see in foliage. It causes wilting. Toxic levels also exacerbate deficiencies of potassium, magnesium, manganese, and iron. The nutrients become unavailable, even though they are present. If excessive amounts of soluble calcium is applied early in life, it can stunt growth. If growing hydroponically, an excess of calcium will precipitate with culfur in the solution, which causes the nutrient solution to suspend in the water and to aggregate into clumps causing the water to become cloudy(flocculate). Once the calcium and sulfur combine, they form a residue(gypsum) that settles to the bottom of the reservoir.
Magnesium (Mg)- mobile
Practical Information: Marijuana uses a lot of magnesium, and deficiencies are common, especially in acidic(pH below 7) soils. Adding dolomite lime to acidic potting soils before planting will stabalize the pH, plus it will add magnesium and calcium to the soil. Add Epsom salts with each watering to correct magnesium deficiencies, if no dolomite was added when planting. Use Epsom salts designed specifically for plants rather then the supermarket-type.
Technical Information: Magnesium is found as a central atom in every chlorophyll molecule, and it is essential to the absorption of light energy. It aids in the utilization of nutrients. Magnesium helps enzymes make carbohydrates and sugars that are later transformed into flowers. It also neutralizes the soil acids and toxic compounds produced by the plant.
Deficiency: Magnesium deficiency is common indoors. The lower leaves, and later middle leaves, develop yellow patches between dark, green veins. Rusty-brown spots appear on the leaf margins, tips, and between the veins, as the deficiency progresses. The brownish leaf tips usually curl upwards before dying. The entire plant could discolour in a few weeks, and if severe, turn a yellowish-whitish tinge before browning and dying. A minor deficiency will cause little or no problem with growth. However, minor deficiencies escalate and causes a diminished harvest as flowering progresses. Most often, magnesium is in the soil but is unavailable to the plant because the root environment is too wet and cold or acidic and cold. Magnesium is also bound in the soil if there is an excess of potassium, ammonium(nitrogen), and calcium(carbonate). Small root systems are also unable to take in enough magnesium to supply heavy demand. A high EC slows the water evapouration and will also diminish magnesium availabilty.
Progression of deficiency:
- No deficiency symptoms are visible during the first 3-4 weeks.
- In the 4th-6th week of growth, the first signs of deficiency appears. Interveinal yellowing and irregular rust-brown spots appear on older and middle-aged leaves. Younger leaves remain healthy.
- Leaf tips turn brown and curl upward as the deficiency progresses.
- Rust-brown spots multiply and interveinal yellowing increases.
- Rust-brown spots and yellowing progress, starting at the bottom and advancing to the top of the entire plant.
- Younger leaves develop rust-coloured spots and interveinal yellowing.
- The leaves dry and die in extreme cases.
Treat deficiency by watering with 2 teaspoons of Epsom salts(mangesium sulfate) per gallon of water. For fast results, spray the foliage with a 2% solution of Epsom salts. If the deficiency progresses to the top of the plant, it will turn green there first. In 4-6 days, it will start to move down the plant, turning lower leaves progressively more green. Continue a regular watering schedule with Epsom salts until the symptoms totally disappear. Adding Epsom salts regularly is not necessary when the fertilizer contains available magnesium. Use a foliar spray of Epsom salts for a fast cure. Another option is to apply magnesium sulfate monohydrate in place of Epsom salts. Add fine dolomite lime to soil and soilless mix to add a consistent supply of both calcium and magnesium over the long term. Always use the finest dolomite lime available.
Control the room and root-zone temperatures, humidity, pH, and EC of the nutrient solution. Keep root-zone and nutrient solution at 70-75F(21-24C). Keep ambient air temperature at 75F(21C) day and 65F(18C) night. Use a complete fertilizer with an adequate amount of magnesium. Keep the soil pH above 6.5, the hydroponic pH above 5.5, and reduce high EC for a week. The extra magnesium in the soil is generally not harmful, but it can inhibit calcium uptake.
Toxicity: Magnesium toxicity is rare and difficult to discern with the naked eye. If extremely toxic, the magnesium develops a conflict with other fertilizer ions, usually calcium, especially in hydroponic nutrient solutions. The toxic buildup of magnesium in soil that is able to grow marijuana is uncommon.
Practical Information: Marijuana loves nitrogen and requires high levels of it during vegetative growth but lower levels during the balance of life. Nitrogen washes away easily and must be replaced regularly, especially during vegetative growth. Excess levels of nitrogen in harvested plants cause the dried marijuana to burn poorly.
Technical Information: Nitrogen regulates the cannabis plant's ability to make proteins essential for new protoplasm in the cells. Electrically charged nitrogen allows the plant to tie proteins, hormones, chlorophyll, vitamins, and enzymes together. Nitrogen is essential for the production of amino acids, enzymes, nucleic acids, and chlorophyll and alkaloids. This important nutrient is mainly responsible for leaf and stem growth, as well as overall size and vigour. Nitrogen is most active in young buds, shoots, and leaves. Ammonium is the most readily available form of nitrogen. Be careful using too much of this form; it can burn the plants. Nitrate -the nitrate form of nitrogen- is much slower to assimilate then ammonium. Hydroponic fertilizers use slower-acting nitrogen compound and mix it with ammonium.
Deficiency: Nitrogen is the most common nutrient deficiency. The symptoms include slow growth. Lower leaves cannot produce cholorophyll and become yellow between the veins while the veins remain green. Yellowing progresses through the entire leaf, eventually causing it die and drop off. Stems and the leaves' underside may turn reddish-purple, but this can also be a sign of a phosphorus deficiency. Nitrogen is very mobile and it dissipates into the environment quickly. It must be added regularly to sustain fast-growing gardens.
Progression of deficiency symptoms:
- Older leaves yellow between the vein(interveinal chlorosis).
- Older bottom leaves turn entirely yellow.
- More and more leaves yellow. Severely affected leaves drop off.
- Leaves might develop reddish-purple stems and veins on leaf undersides.
- Progressively younger leaves develope interveinal chlorosis.
- All foliage yellows and the leaf drop is severe.
Treat deficiency by fertilizing with N or a complete N-P-K fertilizer. You should see results in 4 to 5 days. Fast-acting organic sources of nitrogen include: seabird guano, fish emulsion, and blood meal. Growers also report excellent results by adding bio-fertilizers to stimulate the uptake of nitrogen.
Toxicity: An overdose of nitrogen will cause excessively lush foliage that is soft and susceptible to stress, including insect and fungal attacks. The stems become weak and they may fold over easily. The vascular transport tissue break down, and water uptake is restricted. In severe cases, leaves turn a brownish-copper colour, dry, and fall off. Roots develop slowly, and they tend to darken and rot. Flowers are smaller and sparse. Ammonium toxicity is most common in acidic soils, while nitrate toxicity is more prevalant in alkaline soil.
Progression of toxicity symptoms:
- Excessively lush, green foliage.
- Weak stems that fold over.
- Slow root development.
- Flowers become wispy.
- Leaves brown, dry and fall off.
Treat toxicity by flushing the growing medium of the affected plants with a very mild, complete fertilizer. Severe problems require that more water be flushed through the growing medium to carry away the toxin elements. Flush a minimum of 3 times the volume of water for the volume of the growing medium. Do not add more fertilizer that contains nitrogen for one week so the excess nitrogen in foliage can be used. If the plants remain excessively green, cut back on the nitrogen dose.
Calcium (Ca)- immobile
Practical Information: Cannabis requires nearly as much calcium as other macronutrients. Avert deficiencies in the soil and in most soilless mixes by adding fine dolomite lime or using soluble-hydroponic fertilizers containing adequate calcium.
Technical Information: Calcium is fundamental to cell manufacturing and growth. Calcium is necessary to preserve membrane permeability and cell intergrity, which ensures proper flow of nitrogen and sugars. It stimulates enzymes that help build strong cells and root walls. Cannabis must have some calcium at the growing tip of each root.
Deficiency: Calcium deficiency is somewhat uncommon indoors, but is not uncommon in fibre hemp. Frequently, plants can process more calcium then is available. It also washes out of leaves that are sprayed with water. Deficiency signs may be difficult to detect. They start with weak stems, very dark green foliage, and exceptionally slow growth. Young leaves are affected, and they show signs first. Severe calcium deficiency causes new, growing shoots to develop yellowish to purple hues and to disfigure before shriveling up and dying; bud development is inhibited, the plants are stunted, and harvest is diminished. Growing tips could show signs of calcium deficiency if the humidity is maxed out. At 100% humidity, the stomata close, which stops the transpiration to protect the plant. The calcium that is transported by transpiration is immobile.
Treat deficiencies by dissolving one-half teaspoon of dehydrated lime per gallon of water. Water the deficient plants with calcium-dosed water as long as the symptoms persist. Or use a complete hydroponic nutrient that contains adequate calcium. Keep the pH of the growing medium stable.
Progression of deficiency:
- Slow growth and young leaves turn very dark green.
- New growing shoots discolour.
- New shoots contort, shrivel and die.
- Bud development slows dramatically.
Toxicity is difficult to see in foliage. It causes wilting. Toxic levels also exacerbate deficiencies of potassium, magnesium, manganese, and iron. The nutrients become unavailable, even though they are present. If excessive amounts of soluble calcium is applied early in life, it can stunt growth. If growing hydroponically, an excess of calcium will precipitate with culfur in the solution, which causes the nutrient solution to suspend in the water and to aggregate into clumps causing the water to become cloudy(flocculate). Once the calcium and sulfur combine, they form a residue(gypsum) that settles to the bottom of the reservoir.
Magnesium (Mg)- mobile
Practical Information: Marijuana uses a lot of magnesium, and deficiencies are common, especially in acidic(pH below 7) soils. Adding dolomite lime to acidic potting soils before planting will stabalize the pH, plus it will add magnesium and calcium to the soil. Add Epsom salts with each watering to correct magnesium deficiencies, if no dolomite was added when planting. Use Epsom salts designed specifically for plants rather then the supermarket-type.
Technical Information: Magnesium is found as a central atom in every chlorophyll molecule, and it is essential to the absorption of light energy. It aids in the utilization of nutrients. Magnesium helps enzymes make carbohydrates and sugars that are later transformed into flowers. It also neutralizes the soil acids and toxic compounds produced by the plant.
Deficiency: Magnesium deficiency is common indoors. The lower leaves, and later middle leaves, develop yellow patches between dark, green veins. Rusty-brown spots appear on the leaf margins, tips, and between the veins, as the deficiency progresses. The brownish leaf tips usually curl upwards before dying. The entire plant could discolour in a few weeks, and if severe, turn a yellowish-whitish tinge before browning and dying. A minor deficiency will cause little or no problem with growth. However, minor deficiencies escalate and causes a diminished harvest as flowering progresses. Most often, magnesium is in the soil but is unavailable to the plant because the root environment is too wet and cold or acidic and cold. Magnesium is also bound in the soil if there is an excess of potassium, ammonium(nitrogen), and calcium(carbonate). Small root systems are also unable to take in enough magnesium to supply heavy demand. A high EC slows the water evapouration and will also diminish magnesium availabilty.
Progression of deficiency:
- No deficiency symptoms are visible during the first 3-4 weeks.
- In the 4th-6th week of growth, the first signs of deficiency appears. Interveinal yellowing and irregular rust-brown spots appear on older and middle-aged leaves. Younger leaves remain healthy.
- Leaf tips turn brown and curl upward as the deficiency progresses.
- Rust-brown spots multiply and interveinal yellowing increases.
- Rust-brown spots and yellowing progress, starting at the bottom and advancing to the top of the entire plant.
- Younger leaves develop rust-coloured spots and interveinal yellowing.
- The leaves dry and die in extreme cases.
Treat deficiency by watering with 2 teaspoons of Epsom salts(mangesium sulfate) per gallon of water. For fast results, spray the foliage with a 2% solution of Epsom salts. If the deficiency progresses to the top of the plant, it will turn green there first. In 4-6 days, it will start to move down the plant, turning lower leaves progressively more green. Continue a regular watering schedule with Epsom salts until the symptoms totally disappear. Adding Epsom salts regularly is not necessary when the fertilizer contains available magnesium. Use a foliar spray of Epsom salts for a fast cure. Another option is to apply magnesium sulfate monohydrate in place of Epsom salts. Add fine dolomite lime to soil and soilless mix to add a consistent supply of both calcium and magnesium over the long term. Always use the finest dolomite lime available.
Control the room and root-zone temperatures, humidity, pH, and EC of the nutrient solution. Keep root-zone and nutrient solution at 70-75F(21-24C). Keep ambient air temperature at 75F(21C) day and 65F(18C) night. Use a complete fertilizer with an adequate amount of magnesium. Keep the soil pH above 6.5, the hydroponic pH above 5.5, and reduce high EC for a week. The extra magnesium in the soil is generally not harmful, but it can inhibit calcium uptake.
Toxicity: Magnesium toxicity is rare and difficult to discern with the naked eye. If extremely toxic, the magnesium develops a conflict with other fertilizer ions, usually calcium, especially in hydroponic nutrient solutions. The toxic buildup of magnesium in soil that is able to grow marijuana is uncommon.
