Topsoil Vs. Potting Soil: Which Is Best For My Flower Beds?

No flower can thrive for long without the proper planting medium from which is can draw its water and nutrients, and choosing the right soil is one of the most important aspects of establishing a successful flowerbed. However, knowing exactly which kind of soil you require can be challenging, especially since the differences between different types of soil are often vaguely defined.

If you are establishing a new flowerbed in your garden or on your balcony, some sources will recommend using topsoil, while others will recommended using potting soil. These soil types are both rich in nutrients, but they are far from interchangeable, and knowing when to use topsoil and when to use potting soil can spell the difference between a vibrant flowerbed and a rotting pile of mulch.

What are topsoil and potting soil?

Topsoil's name is largely self-explanatory, as it consists of the shallowest and most nutritionally rich layers of a piece of earth. Where exactly this topsoil comes from tends to differ wildly depending on the manufacturer -- some topsoils are quite literally scraped from the tops of fields and plots of land, while others are created by mixing the necessary components of topsoil together in large silos. Both types of soil are generally mixed with manure and other fertilisers prior to sale.

Potting soil, on the other hand, has a thoroughly misleading name, as some varieties of potting soil contain no soil at all. Instead, they consist of a mix of materials such as peat moss, coconut coir and tree bark, which create a loose growing media ideal for anchoring the roots of young plants and maximising proper water drainage. Some topsoil varieties also contain some seemingly unintuitive ingredients, such as vermiculite (a form of expanding silica clay) which assist with proper water drainage and prevent the potting soil from packing too tightly.

So when should I use each type of soil?

As you can see, these two similar-seeming soils are deceptively different, so making sure you use each type of soil in the right situation is vital for healthy flower growth.

Topsoil is best used if you are planting a flowerbed at ground level in natural soil. This is because it is most effective when mixed with, or laid over the top of, the natural soil in your garden, when it can add vital nutrients to the existing soil without changing its makeup of drainage characteristics too dramatically. Adding topsoil also helps your existing soil retain water more effectively, a constant boon in Australia's typically brutal summer sun.

Potting soil, on the other hand, is far more suitable for raised beds, container gardens and large pot plants. Using it in a traditional ground-level flowerbed can cause water to drain away too quickly from your flowers and can also disturb the natural ecosystems of beneficial bacteria and fungi that exist in your soil and assist in your plants' growth. However, when used in containers, the sterile, well-draining potting soils are ideal, preventing waterlogging that can lead to root rot while providing your plants with nutrients they would otherwise lack.

For more information, contact a company like Freds Lagoon Hardware.