Topsoil vs Compost: What Should I Use?

Jan 30, 2022 | Lawn & Garden

When there is a large variety of gardening products available, it can be hard to decide which product is the most suitable product for your garden. For example, you’ve probably heard of adding either topsoil and compost to your garden, but which one should you use? Keep reading to learn more about topsoil vs compost.

Topsoil vs Compost

Topsoil vs compost: what is the difference?

Compost and topsoil are two popular gardening materials available in the market. Both are different from each other, yet sometimes people get confused about their roles and uses.

The primary difference between topsoil and compost is the ingredients. Because these two products have different ingredients, they typically have different purposes. Although, its best when you can use the two together

Topsoil vs Compost

What Exactly Is Compost?

Compost is a nutrient-rich medium formed by decaying green matter (grass clippings, vegetable peelings, food scraps, etc.) and brown matter (plant materials like dried leaves, twigs, plant roots, wood chips, or paper, etc.).

Both forms of matter are first mixed and then left in a compost pile where their decomposition or composting process occurs with the help of decaying microbes.

A closed compost bin keeps the heat inside, which speeds up the whole process.

You can also add worms to boost composting process speed. It is actually the organic matter that is added to the depleted soil to refresh it and add more healthy nutrients.

For this reason, it is also called soil amendment. It improves the water retention ability of soil, reduces compaction, and also enhances soil structure that promotes healthy plant growth.

Topsoil vs Compost

Different Types of Compost

Compost is categorized into the following types.

Composted Wood Waste

As the name suggests, this kind of compost is formed by the decomposition of wood waste such as wood chippings, dried stems, paper, twigs, etc.

Composted Green Waste

This kind of compost is formed by decomposing common kitchen and garden waste. It may include food scraps, vegetable peelings, dried leaves, roots, etc.   

Composted Manure

The decomposition of manure is what makes composted manure. It has straw particles. This kind of compost is usually used in villages where people keep cows and similar animals.

Sterilized Loam Compost

This form of compost is a mixture of sand and clay. This mixture is properly sterilized to make sure it does not contain any disease-causing microorganisms.

When Should You Use Compost?

You can use compost for different purposes. The common uses of compost include:

  • Improve soil quality
  • Help the soil retain water by using compost as mulch
  • Provide nutrients as a liquid fertilizer (compost tea which is formed by steeping compost in water)

You can apply compost as mulch just like you apply any other form of mulch. For this purpose, spread two to three inches of compost layer on the garden soil. It is best to do it twice a year to get the best results.

You can also use compost to improve the quality of existing soil. For this purpose, dig the soil in your garden or a new or existing lawn, then mix compost with the soil and place the soil back in its place.

If you do not want to use compost as it is, then compost tea is a good alternative option.

Compost tea is prepared by soaking active or matured compost in water. When compost is soaked for one or more days, micronutrients and soil bacteria leach into the water. This nutrient-rich water is then termed compost tea.

You can use compost tea to water the plants. It will provide not only water but also aerobic bacteria and healthy nutrients to the plants. Also, nutrients in the liquid form will be easy to absorb for the plants.

Compost is also helpful in restoring potting soils or potting mix whose nutrients have been depleted due to excessive use.

You can also mix it in the ground soil or topsoil while planting new vegetables or plants in your garden. Knowing how much compost to mix in is key.

You can find pre-made, bagged, compost at one of your local garden centers, or online. If you’re looking for a quality product, check out our article on the Best Compost for Your Garden.

Tip: Using compost works great if you’re looking to plant new sod or grass seed. Mixing compost with the native soil will give your grass seeds a nutrient-filled environment to grow in.

Pros of Using Compost

There are many benefits of using composts. Some of its pros are listed below.

  • It works as a natural nutrient booster and provides active soil microbes (Active SOM). You can spread it on new garden beds to increase their nutrient level.
  • It maintains the natural health of your soil compared to the inorganic fertilizers that ruin your soil’s natural composition.
  • It promotes the growth of all forms of plants, whether it is a vegetable plant, fruit plant, herb, or shrub.
  • You can make it from common household waste products, which makes it cheap and environmentally friendly compared to the fertilizers available in the market.
  • It controls the production of weeds. Weeds are tiny plants that grow in the gardens and compete with the important plants for shelter, nutrients, and water. Therefore, getting rid of them is vital for a plant’s growth.
  • It provides plants and soils the beneficial bacteria that prevent many bacterial diseases and help plants absorb nutrients.
  • It increases soil’s water retention ability, and you can use it for all types of soil.

Cons of Using Compost

Even though compost is very beneficial for your garden, it still has some cons, such as:

  • Compost shows its effects slower compared to the other additives that you can buy from the market.
  • Its production is a prolonged process. It may take months to fully decompose and become mature.
  • You need more space to store and produce compost which can be a problem for people who do not have any extra space in their homes.
  • The decomposition of organic matter forms compost; due to this, it may cause smell even when it is spread in small areas (a large area can be even more smelly).
  • Making compost is a laborious process compared to buying fertilizers directly from the market. 

 What Exactly Is Topsoil?

As the name indicates, topsoil (sometimes called top soil) is the top layer of soil that is present above the rock bed. It is the most nutrient-rich layer of soil and contains organic materials, dead plants, sand, rocks, etc.

Typically, naturally occurring soil will feed nutrients to plants, then natural organic materials (e.g., from animals) and dead plants will replenish the soil – this is part of the natural soil cycle.

However, due to the excessive use of soil in our gardens, it sometimes becomes nutrient deficient. This kind of soil does not support plant growth properly. Therefore, it is important to add nutrients to the layer of topsoil by using compost or fertilizers.

Topsoil is formed over the years when air, decaying plants, decaying animals, chemicals, water, etc., interact with each other and create a growing medium for plants.

Topsoil vs Compost

Different Types of Topsoil

Topsoil is divided into three main kinds which are:

Clay Soil

Clay soil is the type of topsoil that has good water and nutrient retention ability. It has small particles that hold nutrients and water. Then they provided the stored nutrients and water slowly.

Even though it is good that it helps with stability, it has poor water drainage. Therefore, you need to be careful while watering clay topsoil.

Sandy Soil

Sandy soil is not suitable for retaining water and nutrients. Therefore, if your garden has sandy topsoil, you will have to water it more often and add nutrients to the soil more frequently.

Loam Soil

Loam soil contains clay soil, sandy soil, and many important organic materials. It is rich in nutrients, making it the best option for your new lawn that needs nutritious new soil.

When Should You Use Topsoil?

Topsoil is usually removed from the building materials, and then additives like compost are added to it to make it nutrient-rich. You can use it for different purposes like:

  • Creating vegetable garden beds (or raised garden beds) to grow new vegetables
  • Leveling a hole formed due to various reasons like removal of a tree etc.
  • Forming a new lawn before planting fruits, flowers in it

Check out our article on the Best Organic Potting Soil for Vegetables.

Pros of Using Topsoil

There are many benefits of using topsoil. Some of its pros are described below.

  • It provides more nutrients to the plant. For example, when you add a topsoil layer to the already existing soil in your garden, topsoil’s nutrients get absorbed in the soil below. From there, they reach roots and help plants to grow.
  • Adding topsoil to the already existing soil reduces the need to use chemical fertilizers.
  • It allows you to get rid of the uneven lawn as well as improve the quality of the soil.  
  • You can create new lawn areas or flower beds by using topsoil.

Cons of Using Topsoil

Topsoil has certain disadvantages that we have described below.

  • If you are trying to grow plants in the pot by using topsoil, you may not get the desired results. This is because topsoil does not provide as many nutrients as the potted plant needs for healthy growth.
  • Topsoil also contains weed seeds; as a result, weeds may start developing soon. Furthermore, weeds will compete with the plants present in their surroundings, which can hinder the normal growth of your plants.
  • You need to add compost or fertilizers if you want to use topsoil for the potted plants.

Can I Mix Compost and Topsoil?

This article has compared topsoil vs compost, but really they should be used together.

There is no harm in mixing compost and topsoil. In fact, it is the best way of converting poor soil that is nutrient deficient into nutrient-rich soil.

You can buy both products from the market or garden center and then mix them in the right proportion before spreading them on the ground or growing a plant.

Can I Plant Vegetables in The Compost?

It is better to use the correct material, which is topsoil, for the growth of any form of the plant.

Compost only has organic material. It does not provide structural support to the plants, and also has poor water retention ability. Therefore, you should mix soil in the compost before planting any vegetables in it.

Can I Put Dead Plants to The Compost?

Dead plants are a great addition to the compost. However, you should avoid adding an infected or diseased plant to the compost bin because it can also infect healthy plants.

Topsoil vs Compost

Conclusion: Topsoil vs Compost – What Should I Use?

So, what’s the verdict on topsoil vs compost?

Both compost and topsoil have their own roles and purposes. You should choose either of them based on your needs. If you already have topsoil, but it is in poor condition, then you should incorporate compost to enhance its quality.

Growing plants in pure compost is not a good idea because compost has poor water retention and drainage ability. So, you’ll certainly need a mix. Instead, mix it with the topsoil to create a better growth medium for plants.

In short, use topsoil as a growth medium for plants and use compost to improve the quality of the growing medium. Usually, you can place a layer of compost directly on top of the existing soil surface to improve the growth of your vegetable garden.

Mixing the two products properly will give you a quality soil to grow your plants and grass.