Is Unfinished Compost Bad?

Doing composting right is definitely worthwhile if you’re going to do it at all! However, that can lead to an overwhelming amount of questions.

Let’s start with one of the most common questions: Is Unfinished Compost Bad?

Unfinished compost can be very detrimental to the health of plants. It is also technically a waste of time, effort, and the nutrients that make up the primary reason for composting at all. To tell if compost is finished, observe the organic material to see if it is recognizable. If so, the compost is not finished and should not be added to a garden or plot of plants. 

In this article, we will answer the question “Is Unfinished Compost Bad?” thoroughly.

We will also show you how to tell whether or not compost is technically “finished”.

We’ll go over the disadvantages of unfinished compost, and even what to do with it if need be.

Let’s get started!

image / Unsplash

What is Unfinished Compost?

First, let’s make sure we understand what compost is.

Compost can be any organic material that is broken down during decomposition into an earthy material that is actually nutritionally beneficial for plants.

Many people will take ingredients for compost like scraps from their meals, yard waste like leaves or pine needles, and even some types of hay, and isolate them in a place set aside for decomposition.

Sometimes black bags are used, or piles of organic waste all in one spot.

After a period of around 8 months, this material breaks down and can be incorporated into soil as a type of nutritional boost or food for plants.

However, if a compost pile or bag of compost still looks like the ingredients used to make it up, the compost is not “finished”.

What this means is that instead of having a decomposed litter of earth-like material, you’ll still see components that look like lettuce leaves or pine needles, or, to put it plainly, anything identifiable!

How to Tell if Compost is Finished

What you want to see is a consistently dark, rich, crumbling sort of material that actually smells a bit like soil.

Below, you’ll find our common identifiers for mature compost:

  • The compost is not warm, but a mild temperature, and does not retain heat as easily as it might have at the beginning of the decomposition process.
  • The compost is crumbly instead of a liquid.
  • The compost does not have any features of the original matter; it has all been broken down into one consistent material.
  • The compost stops changing shape and appearance altogether.

If you see the opposite of any of the above-listed traits, it is safe to say that your compost is not finished.

If you used the black bag method of composting, return the material to the bag, close the bag, and leave it out in the sun for another few weeks, if not for another month.

What to Do If You Have Unfinished Compost

If, for some reason, you are unable to let the compost pile continue decomposing or you need to use it in some way, you need to be aware that unfinished compost can hurt your plants.

The organic material has not finished decomposing, and especially in the case of food-based compost, the chemicals are not ready to do anything but harm your garden.

Instead, you can use them in one of the following ways:

Use it As a Mulch

Unfinished compost might not be great to use on actively growing plants, but you can still use it as long as it is not under the top layer of soil.

Lay unfinished compost on top of the soil.

As a bonus, compost worms that live in the soil will usually eat some of the unfinished compost and help the break-down process.

Bury It in the Winter

You should never bury unfinished compost around growing plants, as previously mentioned.

However, if it is the winter or the fall, you should be fine to bury the unfinished compost in the soil because they will not be actively growing and absorbing non-decomposed chemicals like nitrogen.

It’s called trench composting

Is it safe to use unfinished compost?

It is safe to use unfinished compost as mulch, but not beneath the first layer of soil. Usually it causes a nitrogen deficiency in plants that are growing and can stunt their healthy development.

In compost tea, it is even more dangerous, as harmful bacteria can still be found on unfinished compost.

How long should compost sit before using?

$The size of the compost pile and how often it is sifted or turned can be huge factors in how long it needs to sit.

The short answer is, a compost pile should sit for however long it needs to for the organic material to turn brown, earthy, and cool.

This can take anywhere from two weeks to more than one year.


To sum it all up, unfinished compost is bad to be used in the traditional compost style on plants.

It should only be used as mulch above the soil because it contains chemicals that can stunt the health of growing plants.

Either allow the compost to finish decomposing, or use it without burying it at all!

You may also ask:

Nadine is a passionate gardening writer sharing practical tips, innovative ideas, and valuable insights on plant and soil care, In her spare time, she tries to convince her plants to grow by singing them catchy tunes.

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