How toGrow BIG Plants the older areas of the plant to areas of new growth . Deficiencies in immobile nutrients are often seen in areas of newer growth because they are locked into the older portions of the plant where they were originally deposited .
So , what are the 18 nutrients ? 1 . Which are macros ? 2 . Which are micros ? 3 . Which are mobile and which are immobile ? Here ’ s a helpful guide , including each nutrient and signs it may be deficient within a plant .
Primary Macronutrients
● Nitrogen ( N ) ― Mobile — Yellowing of entire leaves starting with lower leaves . Affected leaves will eventually die and fall off if not corrected ( photo above )
Phosphorous ( P )
● Phosphorous ( P ) ― Mobile — Purpling of entire leaves starting with lower leaves ( photo above ). New leaves may be smaller and stunted . Older leaf tips darken and curl downward .
● Potassium ( K ) ― Mobile — Dark yellowing ( almost browning ) of leaf edges starting with lower leaves . Brown spots may appear throughout each leaf if not corrected ( photo above on right ).
Secondary Macronutrients
Nitrogen ( N )
● Calcium ( Ca ) ― Immobile –— Extremely slow , stunted new growth with malformed shoots that often die before fully developing .
Potassium ( K )
● Magnesium ( Mg ) ― Mobile — Yellowing between leaf veins starting with lower leaves . Leaf tips will begin to brown and curl upwards if left untreated .
● Sulfur ( S ) ― Immobile — Yellowing of entire leaves starting with upper leaves . Leaf tips eventually burn and turn downwards .
Essential Micronutrients
● Boron ( B ) ― Immobile — Damage at growing tips and stunted floral formations . Shoots and leaves become deformed , contorted , thick and swollen .
● Copper ( Cu ) ― Immobile — Yellowing and browning between leaf veins starting with upper leaves . New shoots wilt and darken .
● Iron ( Fe ) ― Immobile — Yellowing between veins of young upper leaves starting from the base of the leaf and working its way towards the tips . Leaf edges curl upwards if left untreated .
● Manganese ( Mn ) ― Immobile — Yellowing between leaf veins starting with upper leaves . Leaves will become pale and fall off if left untreated .
● Molybdenum ( Mo ) ― Mobile – Yellowing between leaf veins starting with older leaves . Leaves begin to roll up or cup when left untreated .
Nickel ( Ni )
● Nickel ( Ni ) ― Mobile – Burned leaf tips starting with lower leaves ( photo above ).
● Zinc ( Zn ) ― Immobile - Yellowing between leaf veins starting with upper leaves . New leaf and bud growth contorts and leaf blades become thin .
Non-Essential Micronutrients
There ’ s little evidence to support that deficiencies of these elements cause any harm to the plant . They are used in very small amounts and can be beneficial in assisting other essential nutrients in reaching their destinations . More commonly , damage occurs when these nutrients are present in excessive quantities — for example , in overchlorinated water .
● Chlorine ( Cl ) ― Immobile
● Cobalt ( Co ) ― Immobile
● Selenium ( Se ) ― Immobile
● Silicon ( Si ) ― Immobile
● Sodium ( Na ) ― Mobile
A Word of Caution
Unfortunately , arming ourselves with the knowledge of individual nutrients and their deficiencies has its potential pitfalls . At the first sign a nutrient is lacking , our knee-jerk reaction is to immediately increase the amount of that nutrient in the next feeding .
The appropriate first step should be something quite different — check the pH of your soil and / or the solution of water and nutrients you ’ re feeding the plant . Extremely high or low pH levels can prevent your plant from uptaking certain nutrients , EVEN if they are present in sufficient quantities . The ideal pH range for growing cannabis in soil is typically 6.0 to 7.0 . In hydroponics , it ’ s 5.5 to 6.5 . For a complete chart of optimal pH levels on a nutrient-by-nutrient basis , check out our July 2021 article in The EVOLUTION Magazine , “ Water : The Power of pH .”
Additionally , heavily unbalanced nutrients can cause a similar “ lockout ” effect whereby an overabundance of one or two nutrients causes a chemical reaction that may prevent another from reaching the plant .
Not until you ’ ve confirmed your pH is on target and you haven ’ t been overfeeding is it prudent to begin supplementing the nutrients responsible for a deficiency . And even then , proceed with caution , making incremental additions or adjustments .
For more information about YRG , visit
www . year-roundgarden . com or call 816.216.6917 and be sure to tell them The EVOLUTION Magazine sent you .
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