Cultivation Chemistry: Micronutrients – Calcium
We all know about the importance of calcium in our bones and you likely know about the importance of calcium in your cannabis plant. But do you know what’s going on beneath the surface?
Calcium is considered by many to be a secondary macronutrient, although its importance should not be discounted to the “primary” macronutrients (nitrogen, phosphorus, potassium). Absorbed through the roots and transported throughout the plant by the xylem1, calcium serves many critical roles.
To start, calcium acts as a protector from heat, stress, and diseases. Calcium forms calcium pectate in the cell walls which acts as a binder to hold the cells together and improves stability, thereby strengthening the wall. Enzymes secreted by bacteria and fungi impair the cell wall2. Stomata are pores located on the epidermis of the cannabis leaf that facilitate the “inhalation” of carbon dioxide and “exhalation” of water and oxygen. calcium improves the function of the stomata, aiding in heat resistance, as well as supporting heat shock proteins3.
Many other nutrients are required for proper cannabis cultivation and calcium binds to these other nutrients and carries them along. Also, calcium is able to counteract alkali salts and organic acids in the growing media4.
The addition of calcium to your nutrient regiment or using a nutrient blend with calcium will strengthen your cannabis plants, ensure leaves form with the proper shape and structure and prevent heat shock. You can diagnose calcium deficiencies in your cannabis plant with the following symptoms5:
- Yellow and brown spots forming on the leaves and tips starting with the upper leaves. The lower leaves will twist and curl
- Stunted growth with weak stems and slower flower growth
- Minimal root development with possible root death
If you notice these symptoms, it is time to increase the calcium in your soil.