The root of it all

By Dani Sheehan. 

Knowing your soil is the first step toward growing something great. 

Soil is the foundation for everything you plant, build and grow. As landscape professionals, we’re often focused on the visible results: lush lawns, healthy trees, thriving gardens. But achieving those outcomes starts underground. Choosing the right soil, or improving what’s there already, is essential to the health, longevity and performance of a project. 

To ensure you have healthy soil, you need to understand physical, environmental and chemical properties – the right soil supports everything from nutrient uptake and water retention to root development and structural stability. From small residential spaces to urban restoration sites, it pays to know your soil types, and how to talk about them. While there are a variety of soil types, here are five foundational categories every landscape professional should be familiar with. 

1 – Topsoil: The everyday essential 

Topsoil is the uppermost layer of earth, rich in organic matter and full of nutrients and microbes that support plant growth. Commercial topsoil blends often include compost, sand and screened dirt to create a consistent product. Use topsoil to establish lawns, fill garden beds or improve poor native soil before planting. It’s your go-to base layer for any planting project. 

2 – Compost: The soil supercharger 

Compost is decomposed organic matter like food scraps, yard waste or pine compost. It’s packed with nutrients but not typically used on its own. Mix compost into existing soil to improve fertility, aeration and water retention. It’s especially useful when planting vegetables, flowers or in any area that needs a nutrient boost. 

3 – Fill dirt: For structure, not planting 

Fill dirt is dense, compactable material used to shape terrain. It lacks organic matter to prevent settling, making it stable for building on or under. Use fill dirt when leveling a yard, filling holes or building up areas where you’ll install patios, driveways or retaining walls. 

4 – Sand: Drainage and structural aid 

Sand includes natural materials that come from riverbeds or granite rock. It's gritty, quick-draining and often used in construction or to improve soil texture. Use sand as a base under pavers or hardscapes or blend it into heavy soils like clay to improve drainage. It can also be used decoratively in fire pits or xeriscapes. 

5 – Loam: The gold standard for growing 

Loam is the ideal balance of sand, silt and clay. It retains nutrients and moisture while allowing for good drainage and air circulation. Loam is perfect for planting just about anything, from lawns and shrubs to vegetables and perennials. If your client wants lush results, this is the soil to use. 

Why soil conversations matter 

Soil is the engine behind plant health, long-term sustainability and even the success of built elements like turf fields and tree installations. It affects water retention, root development and microbial life, and it changes dramatically from one project site to the next. 

The physical properties of soil, including structure, texture and organic matter, are often more influential than chemical properties like pH levels. Many tree failures and plant declines aren’t caused by poor fertilization, but by compaction, lack of aeration or incompatible soil types. 

That’s why understanding and specifying soil from the start is so critical. Questions you ask early in the project can shape everything below the surface: 

• What are you planting and how large do you want it to grow? 
• Is the site exposed to heavy foot traffic or equipment? 
• Does the soil need to drain quickly or retain moisture? 

Communicating soil choices to clients also sets expectations. Don’t leave a homeowner wondering why you’re bringing in compost or why their sloped backyard needs fill dirt first. Take a moment to explain each type of soil and its function to build trust and educate your customer.  

When you know what’s underfoot, you’ll build a solid foundation for success.