Cannabis additives explained: What they do & why you need them

It’s common for cannabis growers to hit a wall. The plants look fine, they grow steadily, but something’s missing—yields could be better, flavours aren't quite there, and resin production feels underwhelming. More often than not, the issue isn’t poor technique, but nutrition—specifically the absence of additives.

Base nutrients can take your plants only so far. They're essential for growth, but they won’t cover everything your plant needs to perform at its best. That’s where additives come in. Used properly, they fill in the gaps and help plants reach their full potential. If you’ve been relying on just your NPK bottles and getting good results, it might be time to expand your toolkit and take your next harvest even further.

What are cannabis additives?

Cannabis additives are targeted supplements that work alongside your base nutrients—they’re not replacements. You still need NPK (nitrogen, phosphorus, potassium) and micronutrients. However, additives can help you take your grow further by addressing the specific needs of your plants at the right times.

Definition

Cannabis additives are nutrient enhancers designed to improve specific functions of a plant or its growth—root development, flower density, flavour, aroma, pest resilience, and more. Think of them as precision tools in your feeding strategy. You don’t use all of them at once. Instead, choose additives that are right based on the stage of growth and the result you’re after. When used properly, additives make your feeding more effective, rather than more complicated.

Base nutrients vs additives

Before diving into the benefits of additives, it helps to understand what your plants need just to survive—and what they need to truly thrive.

Core nutrients vs enhancers

Base nutrients include the essential macronutrients—NPK—and a suite of micronutrients like calcium, magnesium, and iron. These are non-negotiable. They build the plant’s structure, drive growth, and keep basic functions going.

Additives, on the other hand, provide targeted support. They're used in smaller quantities and aimed at specific outcomes, such as:

• Stronger root system development
• Increased bud weight
• More intense aroma and taste
• Stronger resistance to disease and environmental stress

Why use additives?

Used properly, additives can allow you to get more from your plants. They help unlock the potential that base nutrients alone can’t fully guarantee. Below are the key ways additives can improve your next harvest.

Maximise yield potential

One of the main benefits of using cannabis additives is increased yield. Products that supply extra phosphorus and potassium during bloom help flowers bulk up. Meanwhile, carbohydrate supplements give plants the energy they need to keep producing buds at a high level, while enzymes support nutrient absorption, which in turn helps buds develop more fully.

Multi-stage bloom boosters like Plagron Green Sensation or Plagron PK 13-14 are built for this purpose. They support consistent flower development and make it easier for plants to push out dense, heavy buds.

Plagron Green Sensation

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Plagron Green Sensation

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Enhance flavour, aroma, and resin production

Good cannabis should taste and smell strong, with a thick resin coating. Additives that focus on terpene and flavonoid production help bring out these traits. For example, Plagron Sugar Royal encourages terpenes production in the plant, leading to stronger aromas and higher resin levels. It works especially well alongside PK boosters and bloom nutrients.

Sugar Royal (Plagron)

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Sugar Royal (Plagron)

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Strengthen root development

Strong roots take in more nutrients and make plants more stable and resilient. Additives like Plagron Power Roots promote fast, healthy root growth by delivering essential vitamins and organic compounds.

Good root development also helps plants cope with stress, whether from transplanting, overwatering, or environmental changes. A robust root system is essential for growing healthy, high-yielding plants.

Power Roots (Plagron)

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Power Roots (Plagron)

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Build immunity and stress resistance

Additives that boost plant immunity help reduce disease risk and improve performance in stressful conditions. Growers often use silica, amino acids, and beneficial microbes to boost plant immunity and resilience. They’re no cure-all, but they can help keep pests, pathogens, or stress symptoms from manifesting in the first place.

Plagron Vita Race, used during the vegetative stage and early flowering, is a good example. As a foliar spray, it supports chlorophyll production and improves nutrient absorption, helping plants stay strong even when conditions aren't ideal.

Vita Race (Plagron)

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Vita Race (Plagron)

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How to use additives by growth stage

Using the right additive at the right time is key. Cannabis plants have different needs as they move through the vegetative, flowering, and final flush phases. Here’s how to match cannabis additives to the moment and get the best results.

Vegetative phase

The veg stage is all about building a strong, healthy structure and lush foliage. Additives used during veg should support root health, plant structure, and early stress resistance. Some options to consider include:

• Root stimulators: Products like Plagron Power Roots help young plants build a solid base
• Silica: Encourages stronger stems and better protection against pests and disease
• Microbial inoculants: Improve soil health by introducing beneficial bacteria and fungi
• Vitamin or enzyme products: Ease transplant shock and promote faster growth

Plagron Vita Race is also effective at this stage. Applied as a foliar spray, it boosts photosynthesis and helps improve plant vitality.

Bloom phase

Once flowering starts, cannabis plants shift their focus from growth to reproduction. The additives you use during bloom, therefore, should support flower production, aroma, and resin. Some examples include:

• PK boosters: Products like Green Sensation or PK 13-14 provide extra phosphorus and potassium to support bud formation and size
• Terpene boosters or carbohydrate supplements: Plagron Sugar Royal, for instance, promotes terpenes production and helps with the development of aroma and flavour compounds
• Enzymes: Maintain root function and prevent nutrient lockout during heavy feeding

Using bloom-phase additives in line with your base nutrients can result in larger, stickier buds with better taste and smell.

Flush phase

Towards the end of the grow, nutrients are phased out to help the plant use up any stored salts and prepare for harvest. For the best results, we recommend trying:

• A plain water flush, using only pH-balanced water to clean out excess nutrients
• Flush solutions, which contain additives that help speed up the flushing process and promise improved flavours in the final product

The goal here is a smoother smoke and a more natural flavour. Overfeeding late in the grow can lead to harsh or chemical-tasting buds, which a proper flush helps avoid.

Cannabis additives: A worthy consideration

Many beginner and intermediate cannabis growers stick to base nutrients and get solid results. But when yields plateau or quality stalls, additives are often the next logical step. They’re not essential for every grow, but they can improve the outcome without a major change in routine.

If you want a simple introduction to additives, full-cycle options like Zamnesia Monster Bud Mix include many of the essentials in one blend. For a more targeted approach, starter kits like the Zamnesia Monster Bud Boost Pack or the Plagron Top Grow Box break the feeding schedule into clear stages, making it easier to apply the right product at the right time.

Used with care, additives help you meet the changing needs of your plant at every stage. They can improve root health, flower density, flavour, aroma, and resistance to stress while giving you more control over how your plants develop from start to finish.

Max Sargent

Max has been writing for over a decade, and has come into cannabis and psychedelic journalism in the last few years. Writing for companies such as Zamnesia, Royal Queen Seeds, Cannaconnection, Gorilla Seeds, MushMagic and more, he has experience in a broad spectrum of the industry.

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