One of the keys to maximizing cannabis yields and quality is providing your plants with the ideal nutrients throughout their growth. Whether you’re growing in soil, hydroponically, or another medium, employing the right fertilizers at the proper stages of plant development is crucial for healthy roots and vigorous growth. There’s a lot to consider when exploring the wide world of cannabis nutrients. In this post, we’ll go over the macronutrients and micronutrients cannabis needs, types of nutrient systems, and how to use nutrients effectively to get chunky, resinous buds.
Macronutrients are those that plants need in large quantities and include nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur. The levels of each macronutrient required varies based on the plant’s growth phase. Here’s an overview:
Nitrogen (N) – Fuels overall vegetative leaf, branch, and stem growth. High levels of nitrogen are needed in the early vegetative stage and can cause excessive foliage growth if overfed in the flowering stage.
Phosphorus (P) – Critical for healthy root development and flowering. Phosphorus requirements ramp up during the flowering stage to produce dense, large buds.
Potassium (K) – Potassium helps regulate metabolic functions and is vital for bud production and overall plant health. Like phosphorus, potassium requirements substantially increase during flowering.
Calcium (Ca) – Calcium strengthens cell walls and enhances overall plant structure and resilience to disease. Calcium aids in bud development.
Magnesium (Mg) – Magnesium aids in nutrient absorption and is an essential component of chlorophyll production resulting in healthy green foliage.
Sulfur (S) – Sulfur helps form key amino acids, enzymes, vitamins, and boosts bud growth and terpene development in flowering.
While only needed in small doses, micronutrients or trace minerals play many crucial roles in plant development, health, and quality. The most important micronutrients for cannabis are:
Iron – Vital for chlorophyll production and enzyme systems. Deficiencies cause yellowing of leaves.
Manganese – Helps build enzymes for nutrient uptake. Manganese supports photosynthesis.
Boron – Promotes vigorous vegetative growth and aids bud development in flowering.
Zinc – Important for promoting proper stem growth and structure, flower and seed production.
Copper – Essential for reproductive growth. Copper assists in terpene and resin production.
Molybdenum – Required for nitrogen fixation and metabolism. Molybdenum helps form key enzymes.
There are three main types of nutrient systems used in cannabis cultivation:
Bottled Nutrients – This is the most common system, using brand name nutrient lines specifically formulated for cannabis. Quality pre-mixed nutrients are added to water at different ratios as plants grow.
Dry Amendments – Organic dry amendments like bone meal, kelp meal, alfalfa, and more are blended into soil to release nutrients over time. Can be combined with liquid organic fertilizers.
Hydroponics – In hydro systems, nutrients are fully dissolved into water that circulates past the roots. Allows for precise nutrient monitoring and adjustment.
Popular nutrient lines like Advanced Nutrients, Fox Farm, and Emerald Harvest offer a complete package of grow, bloom, and supplemental nutrients dialed in for cannabis. Mixing your own custom nutrient blend is also an option for advanced growers.
Nutrient requirements change over a cannabis plant’s lifecycle. The optimal feeding schedule is divided into three main growth phases:
Seedling Stage – Very dilute solution of a balanced veg fertilizer. 25-50% strength over 2-3 weeks.
Vegetative Stage – Transition to full strength veg nutrients. Higher nitrogen for leaf and stem growth over 4-8 weeks.
Flowering Stage – Switch to bloom fertilizers high in phosphorus and potassium. Phase out grow formulas over 6-10 weeks.
Late Flowering – Taper off fertilizer, particularly nitrogen, over the final 1-3 weeks. Flush with plain pH water before harvest.
The exact schedule and nutrient ratios will vary based on factors like strain, growth medium, and lighting. Follow manufacturer’s guidelines for your specific nutrients and adjust as needed based on plant response.
Monitoring your plants for signs of nutrient deficiencies can help you adjust your fertilizer regime. Common deficiencies to look for include:
- Nitrogen – Yellowing lower leaves, weak growth
- Phosphorus – Reddish leaves and stems, slow growth
- Potassium – Leaf curling, yellow spots, weak stems
- Magnesium – Yellowing between leaf veins, reddish patches
- Calcium – Wilting young leaves and shoots, stunted growth
- Iron – Interveinal yellowing, poor bud development
Pay close attention as deficiency symptoms appear and use them to tweak nutrient levels accordingly for optimal health.
Your choice of growing media – soil, soilless mix, coco coir, etc – will impact how you deliver nutrients to your cannabis plants. Soil contains some native nutrients that amendments and liquid fertilizers complement and enhance. Hydroponic systems require a complete nutrient solution adjusted to provide the proper levels of each element with no naturally occurring nutrition present.
Match your nutrient system to work synergistically with your chosen growing medium for best results. For example, using synthetic hydroponic nutrients designed for water in an organic super soil would not be an ideal pairing.
Follow these best practices when feeding your cannabis plants:
- Always mix nutrients in the proper order and allow to fully dissolve.
- Shake or stir nutrient solutions vigorously before each use.
- Start at 25-50% strength and work up to full dose to avoid nutrient burn.
- Only make enough nutrient solution for each use to avoid spoilage.
- Check pH after mixing and adjust to 6.0-6.5 range.
- Runoff should be monitored to avoid buildup – flush as needed.
- Keep detailed notes on nutrient ratios and plant response.
With the right fertilizer system dialed in for your individual growing medium and environment, you’ll be rewarded with thriving, robust cannabis plants and premium buds at harvest.
Mr Clones offers detailed blogs related to Cannabis Clones.
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