Bloom Stimulators - why and when should you use them?

Do you long for a rich harvest and massive flowers? This article explains why it's important to use a high-quality bloom booster or activator. Which products will really allow you to unlock the full genetic potential of your plants and enjoy the best fragrance, volume and colour? Read more to find out how to increase the potency of your herbs and maximise your next harvest.bloom

Why and when should you use a bloom stimulator?


An effective bloom stimulator is irreplaceable and should have a place among the nutrition you provide to your plants. The goal of every indoor and outdoor grower is to cultivate beautiful, luxuriant and fragrant inflorescence or juicy fruit imbued with its distinctive flavour - and that's what bloom boosters do.

The taste or smell of the homegrown fruit, vegetables or herbs can be - using organic products - not only intense but 100% natural and organic. Including the appropriate additives (organic, mineral or in the combined form of organomineral additives) in irrigation during the flowering period will result in pure joy from gardening and a delicious feast for all your senses. 

What is the difference between a bloom stimulator and an activator?

We apply bloom activators starting at the end of the vegetative period to initiate flowering earlier than it usually would. Bloom stimulators make the flowering period more intense once it has started and help the plant develop more blooms than it would with just classic bloom nutrition. They also increase the sugar content in flowers and fruit (e.g. the Atami Bloombastic).

How do bloom stimulators and activators work?


They stimulate the plant’s natural metabolism to work faster and improve the efficiency of nutrient absorption. Some add sugar to the soil, which the plant can absorb and doesn’t have to create its own and preserves energy for other processes. Some (e.g. the T.A. Pro Bloom) stimulate the activity of the beneficial microorganisms in the substrate, which help the plants absorb even more nutrients and thrive. 

Bloom stimulators (also called boosters) differ chiefly in ingredients, which have a crucial influence over their specific effects.

  • The basis of Organomineral bloom boosters is the fundamental nutrients (N, P and K). The manufacturers usually enrich the mineral base with added beneficial substances like trace elements, amino acids, vitamins, plant hormones etc. or microorganisms like fungi or bacteria. For example, METROP AminoXtrem Bloom has a high content of base nutrients.
  • Organic bloom boosters contain only 100% natural ingredients. For example, the BioCanna BioBoost is an excellent organic bloom booster made in labs by multiple controlled fermentation of plant matter. It increases the photosynthesis rate and simple sugar production and boosts the natural immune system. You can use BioBoost by BioCanna with any primary fertiliser. 
  • Mineral-based boosters are an artificial way of stimulating blooming. They are most useful in hydroponic systems because they won’t clog the pipes (as an organic additive could). An example of a mineral bloom booster is the classic BioNova PK 13-14.

Which bloom stimulator is the best?

There’s no way we can answer this question unambiguously. It greatly depends on the individual preferences and experience of each grower. However, we can provide an overview of tried and tested products our customers praise to the skies. 

First, we’d like to introduce the Green Sensation - a universal bloom booster by the famous brand Plagron. Besides substances which support bloom formation, it also contains substances which help the plants absorb nutrients (like milk protein, sodium salt of EDTA and lactic acid). Using Green Sensation strengthens the cell structure, which is always helpful - especially if the plants have been subjected to abiotic stress.


The tried and tested classic is the Big Bud Liquid by Advanced Nutrients. If you’re growing plants in coco, we recommend the specialised version, the Big Bud Coco Liquid. To increase the potency of your plants by up to 50-70%, try the sought-after Bud Ignitor


If you favour Advanced Hydroponics, they make the Growth/Bloom Excellarator for the vegetative and flowering phases, which also boosts natural immunity.

As a fully organic booster with only the best ingredients, we recommend the BioBizz TopMax.

If you prefer to use powder fertilisers, we recommend the Green House Powder Feeding Booster.

A long-term bestseller is also the Atami ATA Bloombastic (organomineral) and Atami B’cuzz Bloom Stimulator (100% organic).


If you don’t necessarily need a 100% natural bloom booster, don’t overlook the mineral alternative to the BioCanna BioBoost we mentioned earlier, the renowned and time-tested CannaBoost.

If you’re looking for innovation and pure research, try the Sumo Active Boost by Shogun, perfect for active hydroponic systems. It can remain stable in a nutrient solution tank for up to 14 days! It contains Triakontanol, plant auxins, cytokinins, brassinosteroids, vitamins and amino acids. We covered the full Shogun fertiliser range in a separate article SHOGUN: UK's best fertilisers with an emphasis on research.


TIP: What would you say to a universal booster, which takes an active part in the growing process and flower formation from the very first day? Sounds good? In addition, this product is in no way incompatible with organic harvests. Its name is X-Cel Booster, and it’s one of the first-rate products by the dutch brand BioNova, which emphasises an eco-friendly manufacturing process. Not only does it promise 20% more flowers, but it’s also suitable for any substrate and growing method. The X-Cel booster is part of the BioNova Boost Pack discounted set. If you’d like to know more, read our article: BioNova Boost Pack for Exquisite Flowers and Fruit.


Now you know the basis on which bloom boosters work and their practical use. However, if you have any further questions about the products or need help choosing the right one for your crop, don’t hesitate to contact us at

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