What Type of “Soil” Should You Be Filling Your Raised Beds or Plant Containers With?

Soil vs Soil-Less Media and the Proper Ways of Using Them

When starting out gardening you may or may not have put much thought into the different ways of filling your plant containers or garden beds and the importance of choosing the right medium.

When I started off gardening, I honestly never considered the differences and grabbed whatever bag seemed right at the time based on the marketing title or picture on the bag. Sometimes I didn’t even care and potted up my plant container with whatever bag I had at the time. 

You may get away with this too, but why not understand the differences so you can make a better decision and provide your plants with the best chance of success. 

Who knew there could be so many options to use as “dirt” for gardening. Sure you have native soil in your own backyard which may be all you need, but then you find products on the shelves such as bags of compost, potting mixes, raised bed mixes, garden mixes, and even top soil among other varieties. 

So what is the purpose of all these options and how do they differ? Let me share the basics with you by providing a simple breakdown of the 2 main choices. 

What is Soil-Less Media?

As the name suggests, soilless media is a growing medium that does not involve native soil. 

Example of Common Soilless Mediums 

Soilless mediums are peat moss, coconut coir, vermiculite, and perlite to name a few. These components can be mixed together to create a growing medium that provides your plants the structure they need for stability, as well as provide the necessary water retention, drainage and airflow for the roots to grow.

Soilless Media vs Soil Amendments

Often associated with soilless media but are better categorized as soil amendments (or ways to improve the soil) are things like compost, worm castings, and composted manure. The purpose of these organic amendments is to add nutrients to your growing media. 

Inert or Near-Inert Matter

Soilless media are known to be inert or near-inert matter, meaning they contain little to no nutrition. Peat moss, coconut coir, vermiculite and especially perlite fall into this category, making fertilization important when growing plants in this media.

Understanding the medium you choose will help you be more aware of how you should amend the “soil” for the right growing conditions to meet your plants’ nutrient requirements.

What is Soil vs Dirt?

You may hear the word soil and dirt used interchangeably, or at least I treated them the same when I first started gardening.  Although they do offer different meanings, I’m not sure it really matters how you use the word as long as you understand the difference. 

Soil

When starting a garden in your own backyard you are working with native soil. This soil is made up of minerals, organic matter, and countless microorganisms. The life in your soil plays an important role in helping your plants access the nutrients they need to grow.

Dirt

When you think of the word “dirt” we are describing the soil that has been removed from its environment. This causes it to degrade and become low in organic matter. However, it is possible to bring it back to life over time by improving it with soil amendments such as compost.

When Should You Be Using Native Soil?

In Ground Gardens

Native soil is truly all you need if you are planting a garden directly into the ground, although you could benefit from additional amendments like compost or other organic materials. 

Raised Beds With Open Bottoms

Alternatively you can use your native soil in your raised garden beds as well, as long as they have “open” bottoms for drainage. If your beds are short enough, your plant’s roots may even find their way to the bottom and grow into the earth beneath as long as the soil is not too compacted for their roots to penetrate. 

Tall Raised Beds Also Count

You can also use soil in your taller beds as well. In fact that is what I did with my raised beds because I had already been saving up plenty of “dirt” from my other landscaping projects and knew I would be building my beds 2 feet high and would need plenty of dirt to fill them.

Just remember not all soil is created equal. Some soils have more clay whereas others are sandier in texture. Too much clay will retain a lot of moisture and sandier soils can drain too quickly. Understanding your soil type will help you determine what to amend your soil with to improve its texture as well as improve the nutrients available for your plants to take up.

When Should You Be Using Soil-Less Media?

Containers or Elevated Raised Beds

Soilless media is best used when planting in containers or raised beds that are elevated or have closed bottoms. In these situations, native soil can become compacted, making it difficult for water to drain and for roots to access oxygen.

Benefits of Soilless Media

Soilless growing media is lightweight and designed to maintain good airflow and drainage, which helps prevent waterlogged conditions. Unlike native soil, these mixes resist compaction over time, making them better suited for confined growing spaces.

When using soilless media you have a lower risk of disease as they are more sterile than native soils. Although not completely sterile, they still provide a cleaner and more controlled growing environment for plants offering better drainage, which is a major challenge when growing in containers or closed-bottom beds. 

If the growing media stays too wet, roots will suffocate and rot. Using a lighter, well-draining soilless mix will help you manage the moisture levels in your containers or elevated beds, which in turn will provide your plants with a healthier environment for root growth.

To Summarize: What Did You Learn?

Bottom line, it’s important to understand as a beginner gardener that not all “soil” is created equal. Understanding the differences between native soil and soilless media as well as soil amendments will help you choose the right growing conditions for your plants whether they will be in raised beds or garden containers. 

Hopefully this article has provided you with a more simplistic approach in understanding the options available today, and the best way to use them when starting your own gardens.