Worm Castings VS Compost

Have you ever wondered how compost and worm castings compare to each other?

In this article, I will provide the easiest way to decide which one to buy. Compost and Worm Castings are same; their intended purposes are different. Worm castings are used as a soil conditioner, while compost is left out in the open air in your garden to decompose.

Before going into more detail about these substances, it may be essential to point out that gardeners need more clarity regarding these products. Because both the worm casting and composting processes take a specific amount of time, people often misunderstand this fact and think that “worm casting” means “composting”.

This confusion creates all sorts of myths surrounding worm castings and composting but I’ll get into some details below where I talk about these particular factors.

What are worm castings?

Worm castings are created using earthworms, red wigglers, and other worms to break down organic matter and turn it into compost. The end product is a granular substance primarily composed of earthworms, tiny bits of their poop, and all the bits of food scraps and vegetable waste they consume. Worm castings are usually loose or moist in texture.

It can be made very wet or quite dry. Worm castings have a slightly sweet smell and a sweet earthy taste when placed on the tongue. This can vary depending on what type of worm casting you purchase. Worm castings have a high concentration of “humus,” which helps the castings stay hydrated and aerated. Humus is rich in nitrogen, which also helps to encourage the growth of microorganisms that help to create the composting process.

Humus also contains potash and micronutrients that promote root growth and even help plants with nutrient deficiencies to grow. Worm castings can be used in various gardening projects, from soil amendments to fertilizer applications and even as a compost activator.

What is Compost?

Composting is a process of breaking down organic material into a fertilizer or soil amendment. The by-product of this process is compost. Composting is a beneficial method of using waste materials in the garden.

Composting is commonly associated with gardening, but it is also used in commercial agriculture. It may be used as a soil amendment on non-organic crops such as orchids and roses or as a fertilizer for farm animals and fish. Compost can also be used in your home gardens by using compost tea to water plants. Compost tea is water in which plant waste has been reduced to a compost-like substance that can be applied to plants that need an added nutrient boost.

In the hot compost method, organic material must be mixed to ensure that the pile has ⅔ brown and ⅓ green material. Green materials are better able to help slow the decomposition of brown materials.

The best thing about composting is that you can make your own by dumping vegetables, grass, and other organic material into a pile. Depending on the amount of plant waste you generate, you can get your entire supply for free.

Is worm castings the same as worm compost?

Worm castings and worm compost are not the same things. They are different types of composting waste. Worm castings are the product of mixing organic material with a worm’s cast-off material. They’re also known as worm manure or vermicompost.

These products are typically dark and rich in nutrients, but they can become very wet and hard to work with. They also tend to smell foul, which can be stinky when the food fed to the worms has been added to the compost pile. It shouldn’t take long for these odour-producing materials to decay away, but it can take months or even longer.

What percentage of vermicompost are castings?

The percentage of castings versus other compost ingredients can vary widely depending on the specific system you use, but generally speaking, vermicomposting systems produce a relatively high amount of castings. Most commercial vermicomposting systems have several hundred to a thousand pounds per week. Vermicomposting is always dependent on the outcome of the castings. However, Worm castings and compost typically contain between 20 and 50% organic matter.

Fertilizer Value

Worm castings improve soil structure, add organic matter, and enrich it with nutrients. By adding a layer of worm castings to the soil (2 inches is good), both existing plants and new plants will be helped by this layer of organic matter. The worms love nothing better than eating organic material and making excellent compost. The compost looks like sawdust and is an excellent soil conditioner.

Compost and vermicompost also improve soil moisture retention. It also increases the soil’s natural nitrogen and other nutrients. The worms like the compost but don’t like to eat it, so it does not create the same soil conditions as sawdust or wood chip mulch. The worms do their best if the compost is mixed with sawdust or shredded paper.

What is the difference between compost and worm castings?

Compost vs worm castings differs in many ways, including the materials used.

  • Compost is a mixture of plant and animal materials, while worm castings are made from 100% worm castings.
  • Compost consists mainly of leaf litter, while worm castings include no animal or plant material.
  • Compost cannot be used in worm runs because it contains earthworms, making them sluggish. Worm compost has no earthworms.
  • Worm castings have a higher organic content than compost, with more nitrogen and phosphates, which improve the growth performance of plants.
  • Worm casts have also been shown to make plants healthier by increasing their water-resisting capacity, nutrient-holding capacity, and nutrient uptake efficiency, as well as reducing the number of pests such as spider mites and aphids.

% Composition of Nutrients in Compost

Type% N (Nitrogen)% P (Phosphorous)% K (Potassium) 
Feedlot Manure 2-3 1-1.5  1-2
Crop Residue 1.5-2.5  0.2-0.5 1-2
Dairy Manure 1-2 0.5-1.5 1-2
Poultry Manure 2-4 1-3 1-3
Urban Yard Waste 1-1.5 0.2-0.5  0.5-1.5

How to Make Finished Compost

Compost can be made by placing organic material in a tumbler composter, and then placing it in a sealed container to aerate it. Use a container like a pail or a garbage can as long as it is manageable. To make finished compost, you must ensure that the container you want to place your compost in is well sealed. Most people use black plastic bags to cover the container, but any sealed transparent plastic bag can work.

This is because, during the process, the earthworms will eat through the bag and make holes for oxygen and moisture transfer. In addition, Composting can be done using any container, but adding your organic material in the proper ratio helps aerate your compost and keep it fresh. Finally, Composting is done by creating a pile of organic material and using a shovel or pitchfork to turn it over as needed.

Benefits of Composting vs Worm Castings

  1. Composting requires less space than worm castings.
  2. Composting is a natural process, whereas worm castings are created by man and may contain synthetic material.
  3. You can add compost to your soil once it has been dug out and is ready to plant, whereas worms require a separate preparation process before use. Worms are less effective at removing decaying organic matter from the soil, making it necessary to have an individual bin or pile (compost pile) to get the best results from applying them.
  4. Composting does not require the use of chemicals. Composting is made up of the most significant percentage of green plant material. It will reduce the amount of chemical fertilizer needed in your garden. The use of chemical fertilizer may produce adverse side effects on your plants.
  5. You should use manure with your compost pile because animals are efficient at converting waste into nutrient-rich compost, which helps you to grow healthy food every time you till up your garden hole.


Are worm castings the same as compost?

No, Worm castings are not the same as compost. Compost comprises the most significant percentage of green plant material used for planting and growing. Worm castings are made from animal waste (usually chicken or cow) and can be used in gardening but should not be confused with compost.

Is worm castings better than compost?

No, not necessarily. Both are excellent products and work well together. Worm castings can be used in several ways. They can be applied directly to the soil as a top dressing, mixed with compost for a better-finished product, or blended with other ingredients such as blood and bone meal for an even better effect.

Can you mix worm castings with compost?

Yes, you can add worm castings to compost, but it is best to make the compost first. It will allow the castings to break down more quickly and make the finished product more homogenous.


This article discusses the basics of Composting and how you can use it to make your garden soil more fertile. I hope you like the way I have presented this article. Now that you know the basics of composting, making your own compost pile and benefiting from the worms or manure added to it will be easy. Please leave comments below if you have any questions or want to share your experiences on composting.