Tag Archives: Nutrients

Water hardness, pH and bonsai

I live in London, a city sitting on a giant chalk deposit which formed in the Cretaceous period and stretches all the way to France (via the Eurotunnel)ref Chalk is a form of limestone made up of the shells of marine organisms, and is comprised mostly of Calcium Carbonate (CaCO₃).ref According to my water supplier […] Read more… >

Nitrogen-fixing and bonsai

You’ve probably heard the term ‘nitrogen-fixing’ – it means extracting nitrogen from the air. Which doesn’t seem like it should be too difficult, since nitrogen makes up 78% of airref, but in reality plants can’t use gaseous nitrogen. In nature (ie. where nitrogen is not added artificially as fertiliser) plants mostly rely on microorganisms to […] Read more… >


(Thanks to Dr. Karen O’Hanlon of Probio Carbon for answering some of my questions about biochar). Biochar is a product which has been advertised as a beneficial component of bonsai soil over recent years. So what exactly is it? Biochar is basically charcoal which has been “produced from organic waste using pyrolysis technology under temperatures […] Read more… >

How roots absorb water and nutrients

Unlike animals, plants do not have a digestive system, although the sustainable food trust makes a good argument that ‘soil is the collective stomach of all plants’ref Trees synthesise all of the substances they need to live and grow from 17 nutrients. It’s important to understand that plants don’t ‘eat food’ in the sense of […] Read more… >


The roots of your tree are *just* as important as the above-ground parts, with a lot of responsibilities which aren’t immediately obvious. I’ve summarised the main ones here but there is a lot more detail in separate posts with links provided below. So why are roots so important? Points 1 and 2 are fundamental to […] Read more… >


Biogold is another popular bonsai fertiliser, which may or may not be cagey about its ingredients since the packaging is all in Japanese which I cannot read. Deploying google translate on their website, and searching online yielded some information: Chicken manure isn’t used directly on plants because the organic matter will ferment and generate heat, […] Read more… >

What is organic fertiliser?

The word ‘organic’ in terms of fertiliser does not mean the same thing as ‘organic’ when it comes to food. Organic food follows principles of production which in general do not permit soluble fertilisers and synthetic pesticidesref to be used during the food production. Organic fertiliser means “any substance composed of animal or vegetable matter […] Read more… >