You’ve finally decided to roll up your sleeves and dive into your next big garden project. The excitement of creating a stunning backyard oasis is palpable. Whether you’re envisioning raised garden beds, a terraced landscape, or a vibrant flowerbed, you’re well on your way to bringing your dream garden to life. But here’s something you might not have considered in the rush of planning: dirt.
Yes, dirt. While your initial thoughts may center on plant selection, design, and hardscape features, dirt is an unsung hero in every successful garden transformation. The type and quantity of dirt you choose can make or break your project by influencing everything from plant health to structural stability. Get it wrong, and you could face poor drainage, stunted plant growth, or even collapsing retaining walls.
Let’s explore the types of soil you need to consider, how to choose the right dirt for your garden, and some inspiring project ideas that rely heavily on choosing the proper soil types.
Types of Dirt: Topsoil vs. Fill Dirt
When planning a garden or landscaping project, it’s essential to understand that not all dirt is the same. For most garden projects, you’ll deal primarily with two types of dirt: topsoil and fill dirt. Each serves a unique purpose, and using the wrong one in the wrong area can lead to disaster.
Topsoil: Fertile Soil for Growth
Topsoil is the uppermost layer of soil and is critical if plant growth is one of your project goals. It’s rich in organic matter, minerals, and microorganisms that are crucial for the health of plants. Topsoil is nutrient-packed and offers excellent moisture retention. This makes it ideal for projects where the primary goal is nurturing plant life, including:
- Flowerbeds
- Lawns
- Vegetable gardens
- Raised planting beds
The rich, soft texture of topsoil harbors all the nutrients your plants need to thrive. It creates an environment conducive to root development, making it the perfect growing medium for a lush garden or lawn. However, while topsoil is excellent for plant growth, it’s less suitable for structural projects. Because of its high concentration of organic materials, topsoil tends to shift and settle over time, making it unstable for construction purposes such as patios, support for heavy structures, or even some retaining walls.
Fill Dirt: For Stability and Solid Foundations
Unlike the nutrient-rich topsoil, fill dirt is composed primarily of subsoil, consisting of clay, sand, and small rocks. It contains little to no organic matter, which allows it to be compacted into a hard, stable layer, making it ideal for projects that require stability, such as:
- Building foundations
- Land grading
- Filling holes or leveling ground
- Supporting hardscapes like patios, walkways, or retaining walls
Because of its compact and durable nature, fill dirt offers the structural integrity necessary for supporting heavy construction. Whether you’re building a foundation for a new garden gazebo or leveling a sloping yard to install a patio, fill dirt provides the firm base you need to ensure your project stands the test of time. However, fill dirt doesn’t support plant growth due to its lack of essential organic nutrients. You will need to top it off with topsoil for aesthetic garden features.
Using Both Topsoil and Fill Dirt Together
In many garden projects, a combination of both topsoil and fill dirt is essential. For example, if you’re creating berms or terraces, fill dirt provides the underlying structural base, while topsoil serves as the growing medium for grass, plants, or flowers. Understanding the specific role of each dirt type allows you to effectively use them both and ensure long-lasting results.
3 Inspiring Garden Projects That Rely on Both Topsoil and Fill Dirt
Whether you’re designing a flowerbed or reshaping your yard, understanding the different ways topsoil and fill dirt are used can transform your vision into a workable plan. Here are three great garden projects that seamlessly integrate both types of soil.
1. Creating Berms (Landscaping Mounds)
A berm is essentially a landscape mound that serves both aesthetic and utilitarian purposes. Berms can add visual interest, guide foot traffic, and act as a natural privacy screen around outdoor seating areas. Additionally, they can improve the yard’s drainage by diverting water in desired directions, preventing pooling in problem areas.
How Dirt Is Used in a Berm:
Fill Dirt: The core of the berm should consist of fill dirt for stability and longevity. Fill dirt’s dense, compact nature ensures that the berm holds its shape and doesn’t erode or shift over time.
Topsoil: Once the berm’s shape and structure have been built with fill dirt, adding a top layer of topsoil (typically 12 inches) provides the ideal growing medium for grasses, plants, or small trees you want to feature.
2. Terraced Landscaping
Terraced landscaping involves creating several plateaus or levels on a sloped property, with retaining walls often used to support each tier. This elegant form of landscaping not only adds visual depth but also promotes water drainage and prevents soil erosion—a common issue on inclined properties.
How Dirt Is Used in Terracing:
Fill Dirt: Each terrace should be built with a base layer of fill dirt to support the retaining walls and drainage systems. This creates a dependable foundation that won’t shift or compact over time.
Topsoil: Once the terraces are constructed, spread a layer of topsoil over each level, especially where you plan to grow flowers or vegetables. This will ensure the area is fertile enough to sustain plant life while maintaining the visual appeal of your design.
3. Building Raised Garden Beds
Raised garden beds are perfect for both decorative and functional gardening, allowing you more control over soil quality and ease of planting. They are especially useful in areas where the native soil is poor or unsuitable for planting. Raised beds also offer the added benefit of better drainage and aeration, which is key for healthy root development.
How Dirt Is Used in a Raised Bed:
Fill Dirt (Optional): If your raised bed is quite deep (over 12 inches), fill the lower half with fill dirt. Since the roots from most plants won’t reach this level, using topsoil in this section isn’t necessary and can help you save on costs.
Topsoil: The top 6 to 12 inches should consist of nutrient-rich topsoil, as this is the section where plant roots will grow. This will ensure that your plants thrive, whether you’re growing flowers, vegetables, or herbs.
How to Calculate How Much Dirt You’ll Need
Now that you know which type of dirt to use and where it’s time to calculate how much you’ll need.
Here’s a simple formula for calculating dirt volume:
- Measure the length, width, and depth of the area you need to fill (in feet).
- Multiply the length by the width by the depth to get your total volume in cubic feet.
- Divide that total by 27 (since there are 27 cubic feet in one cubic yard) to determine how many cubic yards of dirt you’ll need.
For example, if you’re filling a raised garden bed that’s 10 feet long, 5 feet wide, and 1 foot deep, the equation would look like this:
10 x 5 x 1 = 50 cubic feet
50 cubic feet ÷ 27 = 1.85 cubic yards
Build a Foundation for Success
Whether you’re constructing raised garden beds, adding terraces, or creating berms for visual interest, the success of your garden project hinges on selecting the right dirt. Topsoil is essential for plant growth, while fill dirt is critical for creating a sturdy, stable foundation.
Not sure how much dirt to order? Dirt Connections is here to help. We can guide you through your dirt needs and ensure timely delivery directly to your site. For all of your garden project needs, don’t hesitate to reach out—contact Dirt Connections in Maryland, Virginia, or Washington DC today to get started.
Ready to turn your dream garden into reality? With the right dirt, anything is possible.
