Glossary, Plant Care
NPK
Also known as: fertiliser ratio
Short definition
NPK is the three-number label on a fertiliser showing its percentage of nitrogen, phosphate and potash.
Nitrogen mainly supports leaf growth, phosphate supports roots and flowers, and potash supports overall strength and flowering. A label reading 10-10-10 has equal parts of each.
Why it matters
Choose the ratio to match the plant: foliage plants usually want more nitrogen, flowering plants more potash. Do not feed a plant that is stressed by heat or too dry.