Iron Deficiency

Iron deficiency in cannabis plants is an issue that can significantly hinder plant growth and bud production if left unaddressed. It occurs when a cannabis plant is unable to absorb adequate amounts of iron, a critical micronutrient required for essential functions such as chlorophyll synthesis and enzyme production.

The most recognizable symptom of iron deficiency is interveinal chlorosis, characterized by yellowing of the leaves while the veins remain green, usually starting with the newer, upper leaves and potentially affecting the entire plant.

Contributing Factors

Factors contributing to iron deficiency in cannabis include high pH levels in the soil or growing medium, excessively cold root zone temperatures, and poor drainage that can lead to root suffocation and impair nutrient uptake.

In hydroponic systems, iron is best absorbed by the plant’s roots when the pH level is within the slightly acidic range, typically between 5.5 and 6.5.

Can Interveinal Chlorosis be a Symptom of Iron Deficiency?

Yes, interveinal chlorosis can be a symptom of iron deficiency in plants. It is characterized by yellowing of the leaves in the areas between the veins, indicating a lack of chlorophyll production due to insufficient iron. Treatment involves applying iron chelate or sulfate to the soil to address the deficiency.

Correcting Iron Deficiency

Correcting iron deficiency in cannabis plants involves adjusting the pH to an optimal level for nutrient uptake and ensuring that growing conditions — such as temperature and moisture — are within the recommended ranges for the plant’s stage of development.

In some cases, supplementing with a chelated iron product designed for plant nutrition can quickly resolve the deficiency, allowing the plant to resume healthy growth and development.

Gardeners must monitor plants closely after treatment to ensure that the deficiency is corrected and be cautious with iron supplements, as excessive iron can lead to toxicity and further health issues in cannabis plants.