Nutrient Feeding Schedules for Cannabis Cultivation

Cannabis cultivation, particularly in controlled indoor environments, requires a precise approach to providing the optimal balance of nutrients to ensure robust and healthy growth. Nutrient feeding schedules, which dictate when and how much of a certain nutrient to administer, are an essential aspect of this process. This article will cover key considerations in creating and maintaining nutrient feeding schedules for cannabis plants, including the basics of plant nutrition, stages of growth, and commonly used schedules.

Understanding Cannabis Nutrient Requirements

Cannabis plants, like all photosynthetic organisms, require specific nutrients to facilitate their growth and development. These nutrients can be broadly categorized into two groups: macronutrients and micronutrients.


Macronutrients are required by the plant in larger quantities and include nitrogen (N), phosphorus (P), and potassium (K). These elements form the basis of the N-P-K ratio seen on most fertilizer packaging, a numerical representation of the relative proportions of these three nutrients. Other macronutrients include calcium, magnesium, and sulfur, which are necessary but not in as large quantities as N-P-K.


Micronutrients, or trace elements, are needed in smaller quantities but are still essential to plant health. These include iron, manganese, zinc, copper, molybdenum, boron, and chlorine.

The nutrient requirements of cannabis plants change throughout their life cycle, with different stages of growth demanding different nutrient balances.

Stages of Cannabis Growth and Nutrient Needs

Cannabis plants generally go through two main stages of growth: the vegetative stage and the flowering stage, each with distinct nutrient needs.

Vegetative Stage

During the vegetative stage, the focus is on developing foliage and structure, so cannabis plants require higher levels of nitrogen and potassium to support robust vegetative growth. It is also crucial to provide a balanced mix of micronutrients at this stage. Feeding schedules during the vegetative phase often involve applying nutrients every watering session or every other watering session, depending on the medium (soil, coco coir, hydroponics) and the plant’s individual response to feeding.

Flowering Stage

In the flowering stage, the plant’s nutrient needs shift towards higher phosphorus and potassium levels to support bud formation. Nitrogen levels are usually reduced as an excess can negatively affect bud development. The feeding frequency can remain the same as the vegetative phase initially, but some growers choose to ‘flush’ their plants towards the end of flowering, a process involving watering without nutrients to clear any potential excess from the plant tissues and improve the final product’s taste and quality.

Common Nutrient Feeding Schedules

While every grower may fine-tune their feeding schedules based on experience, strain, and grow conditions, there are a few commonly used schedules that many find beneficial as a starting point.

Basic Feeding Schedule

A basic feeding schedule for beginner growers often starts with a balanced N-P-K fertilizer in the early vegetative stage. Nitrogen-heavy feeding begins once the plant establishes itself, usually a few weeks into growth. The transition to flowering brings a shift towards phosphorus and potassium-heavy nutrients, with a gradual decrease in nitrogen.

Advanced Feeding Schedule

Advanced growers may opt to introduce additional supplements like Cal-Mag (Calcium and Magnesium), beneficial fungi and bacteria, and specific bloom boosters during flowering. The feeding frequency and quantities also often increase, requiring a careful eye to avoid nutrient burn.

Hydroponic Feeding Schedule

Hydroponic feeding schedules differ from soil or coco coir schedules due to the medium’s nature. Nutrients are directly available to the roots, allowing for more aggressive feeding but also increasing the risk of overfeeding. Hydroponic schedules often involve daily feeding, with careful pH and EC (Electrical Conductivity, a measure of nutrient strength) monitoring.


Creating an effective nutrient feeding schedule for cannabis requires understanding the plant’s basic nutrient needs, the specific demands of each growth stage, and the principles behind different feeding schedules. With careful management and a willingness to adjust based on the plant’s response, growers can optimize their nutrient feeding schedules to maximize cannabis health, growth, and yield. As cannabis cultivation continues to evolve, further research will undoubtedly refine these practices and contribute to our understanding of this complex and rewarding plant.