Plagron Nutrients - Bat Guano - Organic Phosphorus-Rich Soil Booster
Best for: soil growers who want an organic, slow-release phosphorus boost to improve flavour, aroma and flowering performance.
Our thoughts
Guano's been used as a fertiliser for centuries for good reason - it's naturally loaded with phosphorus and releases slowly, so you're not risking a nutrient spike from overdosing. Plagron's version is a simple, single-ingredient organic booster rather than a complicated blend, which makes it easy to slot into an existing feed without second-guessing what else is in the bottle.
Plagron Bat Guano is an organic liquid fertiliser made from dried bat and seabird droppings, which naturally accumulate rich concentrations of nitrogen, phosphorus and potassium along with calcium, magnesium and trace micronutrients like iron and sulphur. It's particularly high in phosphorus (roughly 3-15-4 N-P2O5-K2O), which plants need in larger amounts during the bloom phase for energy transfer and metabolic processes - and it releases these nutrients gradually rather than all at once, which helps prevent the deficiencies and lockouts that can come with fast-release feeds.
Because it's organic and slow-release, guano is typically used as a soil-conditioning booster alongside your main base nutrient rather than as a stand-alone feed. It's suitable for soil and coco growing.
How it compares
Guano-based boosters are a well-established category in organic growing, sitting alongside seaweed and mineral-based bloom boosters.
- Compared with BioBizz Guanokalong, another guano-based liquid, the two work on a similar principle - slow-release organic phosphorus - with brand and price being the main differentiators.
- Compared with a mineral PK booster like Canna PK 13/14, guano releases more gradually and is gentler on soil microbial life, though it won't deliver as sharp or immediate a PK spike late in flower.
- Compared with unprocessed raw guano sold as a dry soil amendment, Plagron's liquid form is easier to dose accurately and mixes straight into your watering can.
It's not the flashiest booster on the shelf, but a genuinely organic, slow-release phosphorus source is a solid addition to a soil feeding routine.
Usage guidance
Guano is used as a supplementary feed alongside your regular base nutrients, not as a replacement for them.
Dosing
Add to your nutrient solution at the rate stated on the bottle label, adjusting for plant size and growth stage - reduce the dose for younger or smaller plants.
When to use
Most useful from the start of the flowering stage onward, when phosphorus demand increases, though it can also support root development earlier in the cycle.
Storage
Keep the bottle sealed and store somewhere cool and dark - like most organic liquid feeds, it's a natural product and best used within a reasonable time of opening.
Technical specifications
- NPK ratio: approx. 3-15-4 (N-P2O5-K2O)
- Source material: dried bat and seabird guano
- Type: organic, slow-release liquid fertiliser
- Key trace elements: calcium, magnesium, iron, sulphur
- Suitable media: soil, coco
- Size available: 1 litre
- Brand: Plagron
Who this is for
- Soil growers who want to boost flowering performance organically
- Growers chasing better flavour and aroma rather than just raw yield
- Anyone building an organic-leaning feeding schedule alongside a mineral base nutrient
- Growers who prefer a slow, steady nutrient release over a fast-acting spike
Our take
Guano earns its reputation the old-fashioned way - it works, it's been used for generations, and Plagron's liquid version makes it easy to dose without any of the mess of handling raw guano.
One we sell a lot of for soil growers looking to add an organic edge to their flowering feed.
