There's a lot of confusion over whether plant food is the same thing as fertilizer. Is there a difference? Let's find out.
Our editors and experts handpick every product we feature. We may earn a commission from your purchases.Learn more.
Plant Food vs. Fertilizer: What’s the Difference?
Updated on Jan. 31, 2025
Even novice gardeners like me know that fertilizer is important to keep plants growing and thriving. But I’ve noticed that much of the internet uses the terms “plant food” and “fertilizer” interchangeably. So, are they really the same thing? The short answer is yes and no. They both aid in plant development, but I’ll help you learn the subtle differences between the two substances, along with some guidance from plant expert Caleb Young. Then you can determine what kind of additives your plants and soil might need for optimal growth and health.
On This Page
What is Plant Food?
As we all know, plants make their own food through photosynthesis. After taking in carbon dioxide and water from the air and soil, a chemical reaction transforms the CO2 into glucose, a food source.
So when I see a package at my local nursery that claims it contains “plant food,” what does that mean? The term “plant food” can encompass a variety of materials, including natural organic matter, compost, and yes, fertilizer. Generally plant food is a soil additive containing minerals that help plants prosper.
What is Fertilizer?
Garden fertilizers enrich soil and provide plants with one or more vital nutrients, usually nitrogen, phosphorus, or potassium.
Fertilizers are not always intended to aid photosynthesis. They address specific plant problems or needs during periods of rapid growth or stress, or aid in overall growth. A fertilizer could contain nitrogen to promote leaf growth, or phosphorus for root development.
Which Do My Plants Need?
This ultimately depends on you, the gardener, and the clues your plants give you.
If you wish to promote a specific characteristic like root growth or leaf development, or replenish a specific nutrient in the soil, choose a fertilizer that targets those specific nutrients. In contrast, if you need a broad mix of nutrients to maintain a healthy vegetable garden, go with a general plant food style fertilizer.
“Every plant has its own unique nutrient requirements depending on their type and stage of growth. Vegetable plants require a high nitrogen content for their green leaves while fruiting plants need more phosphorus and potassium for blooms and fruit development,” says Young. “Always buy a fertilizer that is specific to the plants and also take in consideration existing nutrient deficiencies the plant may already have.”
Applying Them to Plants
Fertilizers and plant food come in a wide variety of forms, including liquids, granules and pellets. They can be synthetic or organic.
It’s common practice to apply plant food regularly throughout the growing season to maintain a steady supply of nutrients. On the other hand, traditional fertilizers are typically applied at specific times and in specific amounts, depending on the type of plant and its growth stage.
When applying any type of fertilizer, “follow the packet instructions and observe the plants response and adjust as needed,” says Young. Additionally, you should test your soil to determine its pH and any nutritional deficiencies.
How Long Do They Last?
In the soil, fertilizers can last for a week to several months. The duration varies depending on weather conditions, type of plant, watering practices and the type of fertilizer.
Liquid fertilizers are only good for a couple of weeks since plant roots rapidly absorb its nutrients. In contrast, granule- or pellet-form fertilizers work for up to 90 days, because it must be broken down in the soil to provide nutrients to the plant.
“In general, houseplants can be fertilized every 2-4 weeks during spring and summer and then nothing during colder months,” says Young. “Vegetables require a higher frequency of fertilizing due to their fast growth rate. Things like grass and established trees need less fertilizer, around three to four times a year.”
Final Thoughts
There’s nothing wrong with adding nutrients to the soil via plant food or a more specific type of fertilizer. Choose the right one based on what your plants need and which minerals or nutrients your soil may be lacking.
Rudyard Kipling, the English poet, writer and Nobel Laureate, wrote in his poem The Glory of the Garden: “Our England is a garden, and such gardens are not made/By singing: — “Oh, how beautiful!” and sitting in the shade.” Sometimes our gardens, whether in England or here in the U.S., need a little help. Whether you do it with fertilizer or plant food is up to you.
About the Expert
Caleb Young is the owner and founder of Rare Indoor Plants. After studying Botany and Interior Design at the University of Otago in New Zealand, Caleb worked for a Botanist for several years where he developed a passion for flowers and plants. Since 2020, Rare Indoor Plants has been offering unique, high-quality plants conveniently shipped straight to customers.
