Not sure whether to use top soil or mulch for your garden? But are good at promoting your plant growth, but in different ways.
The main difference between top soil and mulch is that top soil is used to improve the overall soil quality, the organic matter, and the nutrient content of the garden soil. On the other hand, mulch is used to improve the soil moisture retention, limit weed growth and maintain proper soil temperature.
Keep reading to get a detailed idea of what top soil and mulch are, and how they differ from each other and when to use each one for better plant growth.
Table of Contents
What Is Top Soil?
The uppermost part of the earth that is rich in nutrient and organic content and promotes good plant growth is known as top soil. It forms the top 3-10 inches layer of the soil bed.
What Is Top Soil Made Of
The top soil is composed of organic matter, clay, sand, and mineral particles. It is usually dark in color.
Now here’s the thing: Actually, there isn't a standard definition of a top soil. Any uppermost soil layer can be referred to as Top Soil. This does leave a bit of confusion in determining what type of soil you’re getting.
So the bagged soil you see in stores can be sandy soil, or clay (that’s why be sure to read the labels carefully to get more details on the exact soil you’re purchasing.)
But here’s a brief overview of what a top soil contains and what are its characteristics:
Why It Matters
Did you know that, in nature, it takes almost 5 centuries to make one inch of top soil? Yes, it’s that important.
Every garden and lawn has the most enriched soil layer on its top. But the problem is not all of them are nutrient rich enough to support high plant growth. That’s where the backed top soil comes in.
When To Use It
Here are some of the most popular reasons why people use top soil:
- There are thin spots in the lawn from where the soil has eroded. Adding top soil in those areas adds good soil support for the new grass growth.
- During construction the ground is often leveled and during this process the fertile top soil is removed. So to replenish the nutrient content of the soil and support the growth of new plants, trees, and shrubs when landscaping, the top soil is beneficial.
- Sometimes, no matter how often you water the plants, they just don’t grow as you’d expect. And that happens because of the poor soil quality. So the top soil is added and the soil amendment is done to improve its quality.
- Top soil is used not just for garden soil but also in putting mix. It provides ideal growing conditions for potted plants.
How To Use Top Soil
There’s no fixed time limitations to using the top soil, but most gardeners prefer using it during the springtime before you do plantation
For gardens and lawns, the standard approach is to just spread it over the top layer of the yard. But there’s one problem with it. Since most top soil will be slightly different in composition than the existing soil of the garden, there could be drainage related issues.
So, to prevent this issue, first you need to create a transition layer by mixing the top soil with the existing soil and tilling it properly. The thickness of this transition soil layer can range between 2-3 inches. After that, you can top soil as per your preferences. The standard thickness of the top soil layer is usually below 10 inches.
How To Choose The Best Top Soil For Gardens And Lawns
Here are some helpful tips to choose the best top soil for gardens and lawns:
- Ensure your chosen top soil has a loamy soil texture. In other words, when you grab a small amount of the top soil, it should feel a bit gritty – which indicates that the soil has enough minerals in the soil. Loam soil is the perfect mixture of clay, sand and silt and acts as a great base for plant growth.
- Check back the label of the bagged top soil. Does it contain over 3% organic matter? If yes, then it’s good to go.
- The ideal pH of the top soil should be between 5.5 to 7.5 range.
What Is Mulch?
Mulch is a top protective layer that is added on top of the soil, around plants and trees. It creates a healthy growth environment for plants. The mulch layer applied around plants is less than 3-4 inches in depth.
What Is Mulch Made Of
| Types of Mulch: | Materials: |
| Organic Mulch | Wood chips, bark, saw dust, pine needles, compost, grass clippings, grass hay |
| Inorganic Mulch | Rocks, plastic sheets, fabric |
Why It Matters
It helps in soil water retention, prevents the growth of weeds around the plant, acts as a temperature regulator, and also promotes the growth of microorganisms.
You might wonder how mulch is able to do all that? Well, it’s because it acts as a protective layer around the plant roots and prevents direct sunlight from constantly hitting those regions. And as a result:
- Water evaporation is reduced which ultimately helps in moisture retention.
- Natural cover from sunlight gives a suitable environment for microbe growth.
- Since it acts as a cover around the roots, it prevents extreme heat or cold affecting the plant.
- Also, prevents weed germination around the plants by naturally blocking sunlight near the roots.
When To Use Mulch
Here are some of the most common situations in which mulch can be helpful for you:
- During the dry months when you want to avoid water loss from the soil due to evaporation.
- To limit the growth of weeds, saving you time and effort in garden upkeep. Mulch layer blocks natural light reaching beneath the soil layers which ultimately prevents the germination of weed-seeds.
- To create a temperature moderator around your plant to protect them from extreme temperature fluctuations either in winter or in summer.
- Enhancing the aesthetic appeal of your garden or lawn by applying the mulch neatly around the plants.
- To encourage the healthy growth of newly established flower beds, plants, or trees.
How To Use Mulch
To apply mulch, first clean weeds around the plants. Then, dump small piles of mulch near your plant bed and using your hands, gently spread the mulch around the plants. Follow this video to learn more about mulching a garden bed:
Note: If you’re using organic mulch, it won’t last for a long time. Depending on the type of mulch, you’d have to replenish the soil layer with fresh mulch. For instance, for leaves and grass clippings, you will have to add fresh layers quite frequently. However, pine needles can last longer – typically up to 4 years.
How To Choose The Best Mulch For Gardens And Lawns
If you grow annual or perennial plants in your garden, then organic mulches are the way to go. But for vegetable gardens, your mulching needs would be a little bit different. There, organic compost like grass clippings and compost would work best.
If you want to use inorganic mulch like plastic mulch, you can use them for vegetable gardening of certain plants like tomatoes, and melons. However, if you have acid-loving plants like azaleas then, pine needles would work the best.
Ultimately, what matters the most is more mulching rather than using its specific types. As long as you have properly applied them around the plants, you can’t go wrong.
Got muddy soil? Read How To Harden Muddy Soil
Top Soil vs Mulch
| Comparison: | Top Soil: | Mulch: |
| Overview | Top layer of soil, rich in nutrients and organic matter. | Protective layer placed on top of soil. |
| Composition | Mixture of sand, silt, clay, organic matter – consists of an actual soil mix along with minerals and organic matter. | Mulch can be any material organic or inorganic spread around the top soil layer – consists of Organic materials like wood chips, or inorganic materials like stones |
| Moisture Retention | It doesn’t have any special impact in preventing moisture loss from the soil. | It helps in moisture retention by preventing direct sun rays from falling on the roots. |
| Weed Population Control | It doesn’t help with controlling the weed population around the plant. | It helps in preventing growth of weeds around the plants by preventing the germination of the weed seeds. |
| Microorganisms | Since it’s rich in organic matter, it helps in maintaining sufficient presence of microorganisms. | It also helps in organic matter but by providing a natural cover around the root area. |
| Temperature Control | Doesn’t have any special impact on controlling the temperature of the soil. | Since it acts as a natural cover around the roots, it helps in maintaining a moderate temperature. |
| Purpose | Provides nutrients for plant growth. | Retains moisture, suppresses weed growth, insulates soil. |
| Location | Spread on the surface or mixed into soil. | Spread on top of soil only. |
| Layer Depth | The layer can be up to 3-10 inches thick. | 2-4 inches thick above the soil. |
Raised Beds: Using Organic Material for Healthy Soil
Raised beds offer an excellent solution for gardeners dealing with challenging soil types such as clay soil or low spots. By using organic materials, you can create healthy soil structures ideal for vegetable gardens or new lawns.
Why Raised Beds?
Raised beds provide better drainage, soil temperature control, and soil structure compared to traditional garden beds. They are particularly useful for areas with poor soil quality, allowing gardeners to create optimal growing conditions for plant life.
Adding Organic Material
To build healthy soil in raised beds, incorporate organic materials such as compost, wood mulch, or extra organic matter. These materials improve soil structure, add nutrients, and enhance moisture retention, creating an ideal environment for plant growth.
Best Choice for Vegetable Gardens
For vegetable gardens, raised beds filled with organic-rich soil offer the best choice for optimal plant growth. The addition of organic materials ensures a healthy soil pH level and promotes vigorous plant growth throughout the growing season.
Mulch Thickness: Finding the Right Balance for Your Garden Beds
Choosing the right thickness of mulch is crucial for maintaining soil temperature, suppressing weeds, and promoting healthy plant growth in garden beds. Too much mulch can suffocate plants, while too little may not provide adequate protection.
The Ideal Mulch Depth
For most garden beds, aim for a mulch layer of 2-4 inches. This thickness provides sufficient coverage to retain moisture, control weeds, and moderate soil temperature. However, in areas with extreme weather conditions, such as hot summers or cold winters, adjusting the thickness may be necessary.
Benefits of Proper Mulch Thickness
Maintaining the correct thickness of mulch ensures optimal soil conditions for plant growth. It protects the soil from erosion, conserves water, and enhances soil structure by gradually decomposing and adding organic matter to the soil.
Choosing the Right Type of Mulch
Whether using wood mulch, organic compost, or inorganic materials, selecting the best mulch for your garden beds depends on your specific needs and preferences. Consider factors such as moisture retention, aesthetic appeal, and availability when choosing the type of mulch for your garden.
By carefully balancing mulch thickness and type, you can create healthy soil conditions that promote robust plant growth and enhance the overall beauty of your garden beds.
Conclusion – Top Soil or Mulch: Which One Is Better?
In short, both topsoil and mulch have their unique benefits. Topsoil adds nutrients and organic matter to improve overall soil quality and promote optimal plant growth.
Mulch retains moisture, prevents weeds, and insulates soil temperatures. It protects the plant roots from direct sunlight, and promotes a healthy growing environment in the garden.
The key takeaway here is that topsoil and mulch work hand in hand. Apply nutrient-rich topsoil to establish a solid soil structure and add a protective layer of organic or inorganic mulch on top of it. This combination nourishes plants, while conserving water and controlling weeds. So, Top Soil vs Mulch what are you using? Let us know.
