Deficiency and Excess of Nutrients in Marijuana Plants: Prevention and Correction

Growing marijuana is a science and an art that combines botanical knowledge with agronomic precision. For growers, whether amateur or professional, understanding and maintaining optimal nutritional balance is crucial to ensuring healthy, vigorous plant growth. This balance is essential not only to maximize flower production and quality, but also to ensure the long-term stability and sustainability of the crop.

At the heart of successful agronomic management is the concept of "nutrient deficiency and excess." This term describes situations in which plants have less or more of the essential nutrients necessary for optimal development. Nutrient deficiencies manifest when a nutrient is insufficient and limits the plant's ability to perform vital functions, while excesses can be equally harmful, causing toxicity and imbalances that inhibit growth and can lead to disease or even death. plant.

Identification table of the symptoms of Deficiencies and Excess of Nutrients in Marijuana Plants

For a more precise identification, diagnostic tools such as deficiencies and excesses tables can be used, which provide a visual and descriptive reference of common problems based on the observed symptoms. The table can divide the symptoms by affected plant parts (young leaves vs. old leaves) and by the appearance of the symptoms (discoloration, deformation, necrosis).

A deficiency and excess table is an invaluable tool for marijuana growers, as it provides a visual and descriptive guide to identify nutritional problems based on the symptoms observed in the plants. Here we see a simplified example of how such a table could be structured, focusing on the nutrients most commonly associated with problems in marijuana cultivation:

How to use the table

• Visual Observation: Start by observing the general conditions of the plants. Note any unusual symptoms such as discoloration, deformation, or death of plant tissue.
• Comparison to Table: Use the table to compare the visual symptoms observed with those listed under each nutrient category. Consider both deficiencies and excesses.
• Verification of the Culture Medium: Perform pH and EC tests on the substrate to confirm imbalances. These tests can help determine if symptoms are caused by nutrient availability problems due to soil or water conditions.
• Appropriate Intervention: Based on your diagnosis, adjust nutrition. This may include modifying the nutrient solution, adjusting the pH of the medium, or applying specific nutrients that are deficient.

Soil and Substrate Analysis

Analysis of the soil or substrate provides valuable information about its nutritional content and pH, factors that are crucial for plant health.

• pH Testing: Determine the pH of the soil or hydroponic solution to ensure it is in the optimal range for growing marijuana (generally between 6.0 and 7.0 in soil, and 5.5 to 6.5 in hydroponics).
• Nutrient analysis: Perform soil analysis to measure levels of essential nutrients such as nitrogen, phosphorus, potassium and other microelements. This will help adjust fertilization based on the plants' specific needs.

Plant Tissue Tests

Plant tissue testing involves analyzing samples of plant leaves or stems to determine their nutrient content. This type of analysis is very useful to identify hidden deficiencies that are not clearly manifested through visual symptoms.

• Sampling: Select leaves from different parts of the plant to obtain a complete diagnosis.
• Laboratory analysis: Samples are sent to a specialized laboratory where they are analyzed to determine concentrations of essential nutrients and detect possible toxicities.

Continuous monitoring

Continuous monitoring is key to adapting growing practices to the changing needs of plants throughout their life cycle. Includes:

• Record of observations: Maintain a detailed record of all observations and tests performed.
• Adjust growing practices: Based on test results and observations, adjust irrigation, fertilization, and pest control to optimize the growing environment.

Fertilization Management to Avoid Nutrient Deficiencies and Excesses

Proper fertilization management is essential to promote the healthy growth of marijuana plants and maximize their yield and quality. Below are key practices for adjusting pH, dosing nutrients, and establishing the correct application frequency.

pH adjustments

The pH of the growing medium or nutrient solution is crucial because it affects the availability of nutrients to the plants. An incorrect pH can cause nutrient lockouts, where even if they are present, plants cannot absorb them properly.

• Optimal Range: For most marijuana crops, the ideal soil pH should be between 6.0 and 7.0, while in hydroponics, a pH of 5.5 to 6.5 is preferable.
• pH adjustment: Use pH buffer solutions to raise or lower the pH of your nutrient solution or soil. Constantly monitor the pH, especially after adding fertilizers, as they can upset the pH balance.

Nutrient Dosage

Correctly dosing nutrients is vital to avoid both deficiency and excess. The dosage should be adjusted according to the plant's growth stage and its response to nutrients.

• Nutrient Concentration: Use the fertilizer manufacturer's recommendations as a starting point, but adjust based on plant observation and EC (electrical conductivity) tests that help measure the total amount of soluble salts in the solution.
• Nutrient Balance: Make sure the fertilizer provides an adequate balance of essential nutrients, including NPK (nitrogen, phosphorus, potassium) and micronutrients.

Application Frequency

The frequency with which fertilizers are applied should be adapted to the needs of the plant, which change throughout its life cycle.

• Growth vs. Flowering: During the vegetative growth phase, plants generally require more nitrogen. In the flowering phase, the demand for phosphorus and potassium increases.
• Plant Signs: Reduce the frequency of fertilization if you see signs of excess nutrients, such as burnt leaf tips or unusually vigorous growth. Increase fertility if you see signs of nutritional deficiencies, but do it gradually.
• Root Washing: Periodically, especially in crops in substrates such as soil or coconut, it is beneficial to wash the roots to eliminate excess accumulated salts, which can help prevent nutritional toxicities and restore nutrient absorption.

The combination of these three elements: pH adjustments, proper nutrient dosage and a well-planned application frequency is essential for effective fertilization management. This approach not only prevents problems of deficiencies and excesses, but also optimizes the general health of the plants and improves marijuana deficiencies.

Use of Fertilizers for marijuana plants

The proper use of fertilizers is essential to ensure a balanced supply of nutrients, promoting healthy growth and maximizing the production of your marijuana plants. Choosing and using fertilizers correctly is vital for balanced nutrient supply:

Fertilizer Type:

• Chemical Fertilizers: They are fast acting and provide nutrients directly. For example: VITAMAX PLUS FROM GROTEK , this additive contains a mixture of macro-nutrients and micro-nutrients that make it easier for your plants to synthesize all types of essential molecules. By providing your plants with a wide variety of chemical elements, they will be able to successfully cope with various stress factors and produce their own weapons in the form of chemical compounds. However, excessive use can damage soil and plants.
• Organic Fertilizers: Release nutrients more slowly and improve soil structure. They are ideal for sustainable cultivation, although they may require more time to show effects. For example: BIO FLORES DE CANNA , its components are entirely organic, so they offer natural results while not causing damage to the environment. However, excessive use can damage soil and plants.

Nutrient Balance (NPK):

The balance of NPK nutrients (nitrogen, phosphorus and potassium) is crucial in agriculture and, specifically, in the cultivation of marijuana, since each of these macroelements fulfills essential functions in the development and health of plants. Here I will explain the importance of each one and how you should adjust their proportions throughout the different stages of the plant's life cycle.

Nitrogen (N)

• Function: Nitrogen is essential for the vegetative growth of plants, as it is a key component of proteins, nucleic acids, chlorophyll and other vital molecules.
• Vegetative Phase: At this stage, plants need high nitrogen availability to support rapid, healthy foliage growth.
• Flowering Phase: The need for nitrogen decreases, as the plant's focus shifts toward flower and seed production.

Phosphorus (P)

• Function: Phosphorus is crucial for energy transfer (ATP), photosynthesis, and is essential in the formation of roots and flowers.
• Vegetative Phase: Needed in moderate amounts for healthy root development.
• Flowering Phase: Phosphorus demand increases significantly to support flower development and reproduction.

Potassium (K)

• Function: Potassium is vital for osmotic regulation, enzyme activation and is important for protein synthesis and photosynthesis.
• Vegetative Phase: It is necessary for the general strengthening of plants and helps improve resistance to diseases and environmental stress.
• Flowering Phase: As with phosphorus, potassium is crucial during flowering for the quality and overall health of the flowers.

Specific Formulations:

Specific fertilizer formulations are essential to address the particular nutritional needs of marijuana plants throughout their different stages of growth and flowering. These formulations are designed to provide the ideal balance of nutrients necessary to optimize plant health and maximize flower production. Here I detail how to choose and use specific formulations for growing marijuana:

Growth Fertilizer Formulations for the Vegetative Phase

During the vegetative phase, marijuana plants require high nitrogen content to promote the development of robust stems and leaves. Ideal formulations for this stage usually have a higher proportion of nitrogen compared to phosphorus and potassium.

• Formulation Example: The ideal formula for fertilizers during this stage could be something similar to a 15-5-10 would be suitable for the vegetative phase.
• Objective: Promote rapid and healthy growth of foliage, essential for photosynthesis and structural development of the plant.

Fertilizer Formulations for Flowering

When marijuana plants enter the flowering phase, the emphasis shifts to phosphorus and potassium, which are crucial for flower and fruit development.

• Formulation Example: A typical formula could change to a 5-15-10 or 5-10-15 would be suitable for the flowering phase.
• Objective: Support the development of large, healthy flowers, improve the quality and density of shoots, and strengthen plant resistance.

Tools for Nutrient Control

To ensure a healthy and productive marijuana crop, it is essential to have the right tools to monitor and control the plants' environment, especially when it comes to nutrients and environmental conditions. Here are some of the most important tools:

PH, EC and Temperature meters .

These devices are essential for effective nutrient management in marijuana cultivation:

• pH meters: These meters help determine the acidity or alkalinity of the substrate or nutrient solution. Maintaining proper pH is crucial because it affects the availability and uptake of nutrients by plants. An incorrect pH range can cause essential nutrients to become inaccessible.
• Electrical Conductivity (EC) Meters: EC meters measure the amount of soluble salts in the substrate or nutrient solution, which is an indicator of nutrient concentration. Monitoring EC allows adjustment of the strength of the nutrient solution to prevent overfertilization or nutrient deficiency.

Practical use:

Perform regular pH and EC measurements before and after each nutrient application to ensure levels remain within optimal ranges. Adjust the concentrations of your nutrient solution based on EC readings and modify the pH with buffer solutions as necessary.

Humidity Controllers

Controlling environmental humidity is vital to avoid plant health problems such as mold or root rot, and to facilitate optimal nutrient absorption:

• Thermohygrometers : These devices measure the relative humidity (RH) in the environment. Maintaining adequate humidity is crucial, especially in sensitive stages such as germination and flowering.
• Air Dehumidifiers / Plant Humidifiers : Depending on the hygrometer readings, you may need a dehumidifier to reduce humidity in very humid climates or periods, or a humidifier in environments that are too dry.

Practical use:

Maintain relative humidity between 40% and 60% for most stages of growth. This may vary slightly depending on the specific phase of the plant's life cycle. Use hygrometers to constantly monitor humidity and adjust the environment with humidifiers or dehumidifiers as necessary to maintain optimal balance.

Cultural Practices to Prevent Excess Nutrients

Implementing appropriate cultural practices is essential to maintain the health of marijuana plants, prevent nutritional imbalances, and ensure optimal development.

Root Washing

Root washing is a procedure that helps eliminate excess salts and nutrient accumulation in the growing medium, preventing nutritional toxicity and improving the overall health of the plant.

• When to do it? It is advisable to flush the roots before the flowering phase to prepare the plant for optimal nutrition during flowering. It is also useful as a corrective measure when symptoms of excess nutrients are observed.
• Procedure: To wash the roots, use clean, pH-adjusted water. Water the plants with a volume of water equal to three times the size of the container in which they are planted. This will help drag accumulated nutrients out of the substrate.

Root washing is an essential technique that can significantly improve the quality and potency of your crops. Learn When and how to wash roots in Marijuana , this is a crucial practice to eliminate excess nutrients and ensure that your plants grow healthier and stronger.

Deficiencies and Excesses in the Growth Phases of Marijuana Plants

Managing marijuana deficiencies and excesses during the different stages of plant growth such as germination, seedling and vegetative growth is essential to establish the foundations of a healthy and productive crop. Each phase has specific nutritional requirements and, therefore, particular strategies to prevent and correct nutritional problems.

Germination Phase

During germination, marijuana seeds primarily need adequate moisture and heat to activate the seed's metabolism and begin growth. Nutrients at this stage are not critical, since the seed contains enough reserves to reach the development of the first true leaves.

• Deficiencies and Excesses: At this stage, excess water is a greater concern than excess nutrients. A very wet substrate can cause seed rot. It is important to keep the substrate moist but not saturated.
• Management: Application of additional fertilizers is not recommended until seedlings are well established.

Seedling Phase

Once the seedling develops its first true leaves, it begins to need an external supply of nutrients, although in very small quantities.

• Deficiencies: The most common deficiencies at this stage may include nitrogen if the seedlings turn pale and show stunted growth. Iron deficiency is also common, which manifests itself as chlorosis (yellowing of the leaves while keeping the veins green).
• Excesses: Overfertilization is a common problem at this stage and can lead to "burning" of the roots, showing as burnt tips on the leaves.
• Management: Use a dilute solution of a balanced fertilizer, applied with caution and in small quantities. Make sure the substrate has good drainage and adequate aeration.

Grow Green House Feeding

Green House Feeding Grow is a powder fertilizer, designed specifically for plants in the growth phase, including cuttings and mother plants. This product helps to properly nourish young plants, ensuring healthy and vigorous development.

Main Features:

• Product Type: Powdered Fertilizer
• Nitrogen Content: 24%
• Phosphorus Content: 6%
• Potassium Content: 12%
• Solubility: 100% soluble in water
• Applications: Suitable for hydroponics, aeroponics, NFT, coconut and soil.
• Dosage: Varies depending on the growth stage, from 0.5 grams per liter to 1.5 grams per liter for outdoor plants.

Benefits for Seedlings:

• Balanced Nutrition: Promotes robust and healthy growth.
• Versatility of Use: Suitable for different cultivation methods.
• Easy Application: Mixes easily with water, ideal for automated irrigation systems.
• Strengthening against Stress: Helps plants endure prolonged stress situations, preparing them for later phases of development.

Vegetative Phase

During the vegetative phase, marijuana plants experience rapid growth and require greater amounts of nutrients, especially nitrogen.

• Deficiencies: Nitrogen deficiency is common and shows up as a yellowing of the oldest leaves that progressively affects the entire plant. Magnesium and calcium deficiencies can also appear, especially in substrates that are not well balanced.
• Excesses: Excess nutrients can manifest in the form of burned leaf tips, slow growth and very dark green leaves. Excess nitrogen can inhibit the absorption of other nutrients such as potassium and magnesium.
• Management: Gradually increase the amount of fertilizer as the plants increase their leaf mass. Maintain a proper NPK balance for vegetative growth, typically with a higher nitrogen formulation. Perform regular monitoring of pH and electrical conductivity (EC) to ensure that nutrients are available and in adequate concentrations.

BAC Fast Food Mineral

Bac Fast Food Mineral is a mineral fertilizer specially formulated for growing autoflowering marijuana. Its balanced composition of minerals and seaweed is designed to maximize bud fattening and improve resin production.

Main Features:

• Type: Mineral fertilizer
• Use phase: Vegetative phase
• Composition: Minerals and seaweed extracts
• Format: Available in 750 ml, 2 l and 4 l
• Application: 3ml per liter of water from the third week of cultivation, increasing to 4ml per liter in the fourth week

Benefits in the Vegetative Phase:

• Stimulates growth: Provides essential nitrogen for the development of the root system and leaf mass.
• Prepare for flowering: The seaweed in its formulation helps prepare the plant for abundant flowering.
• Easy use: Designed to be applied directly to irrigation, simplifying its use in different growing systems.

Flowering phase

The flowering phase in marijuana cultivation is critical, since during this period the plant concentrates its energy on the production of flowers or buds, which will ultimately determine the quality and quantity of the harvest. In flowering, the need for nitrogen is reduced but the demand for phosphorus and potassium increases to support flower development. It is also a critical time to ensure the availability of micronutrients such as boron and molybdenum.

• Deficiencies: Small flowers and poor shoot development (phosphorus), chlorotic leaves and flower drop (potassium).
• Excesses: Excess nitrogen can result in excessive leaf growth at the expense of flower production, and excess phosphorus can block the absorption of other nutrients such as magnesium and calcium.

Bloom PH Perfect by Advanced Nutrients

Bloom pH Perfect is a base fertilizer that is used in both the growth and flowering phases. It is designed to ensure proper pH automatically, allowing for better nutrient absorption and resulting in an abundant, high-quality harvest.

Main Features:

• Type: Liquid fertilizer
• Stages of use: Growth and flowering
• Technology: pH Perfect, regulates pH automatically
• Composition: 1% Nitrogen, 3% Phosphorus, 4% Potassium, 0.2% Sulfur
• Available formats: 500 mL, 1L, 5L, 10L, 20L

Benefits in the Flowering Phase:

• Improves Nutrient Absorption: Maintains pH in the ideal range without manual adjustments.
• Promotes Abundant Flowering: Promotes optimal flower development and resin production.
• Versatility: Suitable for all types of cultivation systems.