Are your younger leaves of your plant starting to fade, yellowing between the vein, or in the margins, tips of leaves discoloring and dying? Then you might be starting to suffer from a Zinc deficiency. The discoloring chlorosis pattern left by a zinc deficiency will be accompanied by less internode spacing and small, often cupped upward lower leaves that eventually turn tallow and die. Vertical growth will stall and bud growth won’t happen at all.
Zinc, a micronutrient, is semi mobile and aids in metabolic process like protein synthesis, conversation of basic starches to usable sugars creating both carbohydrates and chlorophyll, making Zinc essential for optimal photosynthesis. It also has an affect on stem elongation, growth and aids in a plants ability to withstand cold weather by
Zinc is best absorbed between pH range of 5.5 and 6.5, and while it has been shown that zinc deficiencies will happen in environments with high P, like late flower for cannabis, adding extra zinc tends to correct this immediately.
Zinc deficiencies can be a result of a number of biotic and abiotic reasons. High active populations of Mycorrhizal fungi and or overwatering have a similar outcome but different effect on the roots, limiting their ability to absorb some nutrients like zinc creating deficiencies. It is believed almost 50% of Zn uptake happens because of Mycorrhizal fungi in your media.
While correcting a zinc deficiency is easy, some the damage done may remain for the life of the plant, so be sure to be aware that old damage is not signs of new damage when correcting a zinc issue.
The solutions to a zinc deficiency:
Adjust pH to Correct Range.
- In soil, zinc is best absorbed by the roots in the 6.0 – 6.5 pH range.
- In hydro, zinc is best absorbed by the roots in the 5.5 – 6.0 pH range
More likely than not if you are seeing a zinc deficiency, it is because your medias pH is out of optimal absorption range. Changing this is as easy as a leachate or flush, with distilled water, at 5 times the medias volume then recharge with balanced nutrients at correct pH range.
If you suspect your growing cannabis plant has a zinc deficiency due to too-high pH, flush your media and also recharge with a balanced nutrient solution.
Give the Right Nutrients
Truth be told, most cannabis growers don’t need to add more zinc in response to a zinc deficiency! Most nutrient lines have plenty and the med
So simply having good standards and practices on plant treatment like watering and fertigation(feeding) will drastically affect a plants ability to remain healthy
Once the source of your Zinc deficiency is corrected continue to watch for further issues and remember some damage will repair itself other damage is permanent.