Part 18 of a series by Eugene Howell
Considering how little soil a bonsai tree lives in, fertilizing bonsai trees is especially important. But which fertilizer should you buy for your bonsai? When you look at a bag of fertilizer you’ll see a set of three large numbers written across the front that look something like “8-6-4” or any other combination of three numbers. Every bonsai enthusiast must know how to relate these numbers to the needs of each type of bonsai tree they’re growing.
In a previous article we learned that these numbers represent the content of Nitrogen (N), Phosphorus (P), and Potassium (K) contained in the fertilizer, in that order. The numbers written on fertilizer labels are actually percentages. So, for example, the number 5-3-15 means 5% of the weight of that bag of fertilizer is nitrogen, 3% is phosphorus, and 15% is potassium.