Zinc is a mineral and one of many essential micronutrients necessary for a healthy plant diet. Despite cannabis requiring an astonishingly small quantity of it, it is nonetheless crucial for numerous physiological activities. Zinc is used by the cannabis plant to build proteins and macromolecular structures like membranes. It also fundamental to regulate enzyme function. Zinc is also co-factor of gene expression by stabilising both DNA and RNA structures. The growth hormone auxin requires zinc to operate.
You may start noticing a plant is not growing as vigorously as it should. Internodal distance is progressively shortening. New growth shoots look a little different than earlier ones, like if they were shy to open up. Shoot tips will congregate, wrinkling up close together. Once they finally do open and start to stretch out, leaves will begin to yellow from the veins out.
By this point, the leaf is completely yellow, reddish and brown – becoming crumbly and crisp. Buds will contort, start drying up and will eventually die off. This is a doomsday scenario when no corrective measures are taken. With a little knowledge and care, it is something relatively simple to deal with.
Troubleshooting one deficiency will help deal with others when growing marijuana. This guide will show how to spot zinc deficiency as soon as possible.
Excess zinc will primarily lockout iron which is easier to spot. On much rarer occasions, zinc levels may become so high it becomes toxic. If this occurs, the cannabis plant will quickly die off. This last scenario is almost implausible to think of!
Zinc is an immobile element. This means that once deposited it can no longer be relocated to other parts where it is needed the most. When a deficiency happens, older parts of the plant cannot distribute zinc reserves from one place to another, as it can with nitrogen or phosphorous. Therefore, early signs of zinc deficiency occur at the newest growth zones, generally at the top.
So we will focus on zinc deficiency. A direct zinc deficiency is not a common occurrence and usually a side effect from tertiary causes. More often than not, it is pretty straightforward to fix.
Unless you are growing in an entirely new or unknown type of soil, the most common cause of zinc deficiency in marijuana is water pH imbalance. As pH becomes too alkaline, the roots become incapable of absorbing this mineral trace element. Other micronutrients like manganese and copper quickly become unavailable. Nitrogen and calcium start getting affected too.
The main disadvantage of organic growing is that correcting deficiencies can take a lot more time. So the best solution is prevention. Keep monitoring your pH! Since organic growing is so permissive regarding pH, growers tend to stop checking their primary water source. In some regions, be it municipal or well water, pH can fluctuate up to 3 to 4 points within the same year.
Zinc is micronutrient of vital importance when growing Weed. It aids growth hormone auxin and DNA. Lack of this element will seriously hinder your yields
2.) Give the Right Nutrients
1.) Adjust pH to Correct Range
4.) Watch for Recovery
The truth is, most cannabis growers don’t need to add more zinc in response to a zinc deficiency!
If you suspect your growing cannabis plant has a zinc deficiency due to too-high pH, flush your system with clean, pH’d water. This will remove any nutrient salts that may be affecting the uptake of zinc and help restore pH to the proper levels.
Note: Sometimes a cannabis zinc deficiency (like all deficiencies) can be triggered by stressful conditions and may clear up on its own after the period of stress is over. However, to minimize damage it’s important to react to any growing problem as quickly as possible, especially in the flowering stage.
- In soil, zinc is best absorbed by the roots in the 6.0 – 6.5 pH range (although it’s generally recommended for soil growers to keep pH in the 6.0-7.0 range, zinc tends to be absorbed better on the lower side)
- In hydro, zinc is best absorbed by the roots in the 5.5 – 6.0 pH range (although it’s generally recommended for hydro growers to keep pH in the 5.5-6.5 range, zinc tends to be absorbed better on the lower side)
In fact, most growers have actually already given plenty of zinc to their cannabis plants since it is found abundantly in most tap water. If you’re using quality soil or cannabis-friendly nutrients, you probably don’t need to worry about adding more zinc. In general, zinc deficiencies are more likely to appear when a grower is using heavily filtered or reverse osmosis (RO) water to feed plants since any zinc has been removed, but pH is a much more common reason growers see zinc deficiencies in their cannabis plants.
If you cannot get rid of a cannabis zinc deficiency, please consult our 7-Step Cure to 99% of Cannabis Growing Problems
Problem: A cannabis zinc deficiency causes younger leaves to start yellowing in between the veins. Leaf tips get discolored and may start dying.