The Spruce / David Beaulieu
Beginning gardeners sometimes confuse the terms “compost” and “fertilizer.”
This is understandable because there’s some overlap between the two.
Compost is an even more complex topic since compost serves a number of different functions.
The Spruce / David Beaulieu
What Is Compost?
At the most basic level, compost is decomposed organic matter.
However, many forms of organic matter are decomposing in many different locations all the time.
Many gardeners keep such a pile in their backyards to make their own compost.
Fertilizer, by contrast, is typically something you buy.
There are four basic steps to take when making compost:
Bacteria eventually find your pile.
They help it heat up, and this heat breaks down (decomposes) the organic matter.
The resultant product looks like soil to the untrained eye but offers far more value than average soil.
This adds to the confusion about the difference between compost and fertilizer.
Compost is better thought of as a “soil amendment” than a fertilizer.
It can improve soil structure and thereby achieve better drainage, aeration, and moisture retention.
It also contains beneficial microorganisms and microbes that can aid in plant nutrition and make plants more disease-resistant.
What Is Fertilizer?
Fertilizer supplies your plants with nutrients.
A fertilizer falls into one of two categories, chemical or organic.
A chemical fertilizer is an artificial product.
That’s the good news.
The bad news is that these products can be harmful if used incorrectly.
Too much chemical fertilizer can burn your plants and different plants require different types of fertilizer.
An organic fertilizer is a natural product.
Can You Use Compost and Fertilizer Interchangeably?
Compost and fertilizer should not be used in place of each other.
Using compost achieves certain results that fertilizer cannot.
For example, fertilizer won’t improve the structure of your soil.
When to Use Compost vs. One example is whena tree or shrub fails to flower.
Sometimes, the problem is a lack of phosphorus, which can be solved by applying bone meal.
Sometimes, chemical fertilizers are just more convenient.
This is especially true for feeding the lawn.
Manyfeed their lawns up to three timesannually, based on schedules developed by fertilizer companies.
One of the best benefits of compost is that it can be used with good results anytime.
