The Difference Between Plant Food and Fertiliser

Like humans, plants need certain nutrients in order to survive. So if you have a plant, and it doesn’t exactly look like it’s thriving, you may decide to give it a little nutritional boost. But does it need plant food, or fertiliser? And what’s the difference between the two? Here’s what to know.

The difference between plant food and fertiliser

Although the terms are often used interchangeably, plant food and fertiliser are not the same thing. The biggest difference is that plant food is made by the plants themselves, while fertiliser is a synthetic or natural substance that is added to a plant’s soil. Here are a few more specifics:

Plant food

The easiest way to remember the difference between plant food and fertiliser is that only plants can make plant food: It’s not something that can be purchased (no matter what product labels say). To produce the simple sugar they use as food, plants convert water, carbon dioxide, and sunlight during photosynthesis, and absorb nutrients in the soil through their roots.

When a plant isn’t able to get the nutrients it needs through its soil, it may benefit from the addition of some fertiliser or compost to make up for the nutritional deficits.

Fertiliser

The nutrient content in soil depends on a variety of factors, including its texture (loam, loamy sand, silt loam), organic matter content, and pH. Testing your soil is the best way to figure out which nutrients are present in sufficient amounts, and which you may want to add to the soil using fertiliser.

Commercial fertiliser comes in formulations with different ratios of nitrogen, phosphorus, and potassium — the nutrients plant need in the largest amounts. This Lifehacker article from May 2021 decodes the letters and numbers on fertiliser bags, and explains how to select the kind that would most benefits your plants.

Additionally, this page from the University of Minnesota Extension provides further details on the different types of fertiliser, and when to use them.