Understanding NPK and Nutrients

A plant that yellows, stalls or burns at the tips often has a pH or EC problem that was never checked. Joseph explains how to measure, calibrate and correct both, using the kit he actually relies on for his own grow.

Three letters, three numbers, and yet half of the burnt leaves I come across come from a badly read label, not a bad fertiliser. Here I show you how to decode an NPK, why two products with similar ratios can need doses ten times apart, and how to feed without overloading your plants.

People often ask me why I focus on what happens below the pot rather than above it. The answer: a plant never feeds itself alone, it delegates part of the work to fungi and bacteria settled around its roots. Here I break down that living partnership and where each product fits.