The Soil Auger – Our New Tool for Tree Planting!

Posted on Updated on

Our new soil auger – it won’t be this shiny for long!

Today Oakvillegreen staff were “oohing” and “aahing” over the latest addition to our tree planting toolkit – a shiny new soil auger! This sturdy little tool can bore into the soil and pull up a core that’s up to 1 foot deep – revealing what lies beneath.

But what does a soil auger have to do with tree planting? As it turns out, quite a lot.

You see, one of the most important factors determining whether a tree (or any plant, for that matter) will survive in its new home is the soil type. Different tree species like different types of soil, so it’s really important that we know what kind of soil we have before we decide what species to plant.

Different colours can indicate different soil types. Loam is usually dark brown, indicating high organic content. Clay is generally a lighter grey-brown colour.

Soils can range widely in their texture, the nutrients they contain, the amount of organic matter present, and a whole bunch of other characteristics. However, based on particle size, soil can be grouped into 3 main categories: sand (largest particles), loam (usually considered the best for plant growth) and clay (smallest particles). Of course, these categories are not black and white – we often find soils that are somewhere in the middle, leading to designations like “sandy loam” or “clay loam.”

Regardless, having an idea of the soil type provides a starting point for species selection when it comes to tree planting. Some species, like the Freeman maple, can handle any kind of soil. However, other species are more picky – like the black walnut, which only likes loam. This means that it’s important to research any species you’re interested in planting to find out its soil preferences.

The hackberry is one of our tough native species that can grow in compact clay soils, like those found in new developments. Photo by Brenna Anstett, LEAF.

Soil is also one of the major reasons why it can be difficult for plants to thrive in new developments or other areas that have recently undergone construction. When new developments are built, the native topsoil is usually stripped away, and replaced by a relatively shallow layer of extremely compacted clay – great for building on, but not for planting on. This clay does not contain a lot of air space (“pores”), meaning that it can be difficult for new roots to push through. The lack of air space also means there is also less oxygen, which roots need to survive. All of this means that if you’re planting in a new development, the list of plant species that you have to choose from can be limited. Thankfully, there are a few hardy native species that can tough out that compacted clay – hackberry, serviceberry and honey locust, to name a few.

Since we’re all about planting the right tree in the right place, we decided it was high time we had a soil auger to help us determine soil type before planting. When you sign up for the Oakville Backyard Tree Planting Program (at, our arborist will use our new soil auger at your yard consultation to determine (by the colour and feel of the soil) what kind of soil you have. The arborist will consider your yard’s soil type, along with its sunlight and moisture conditions and your personal preferences, to recommend species that will thrive in your yard.

So, before you decide to plant something, whether it’s a large growing tree or just a small perennial, make sure you take the time to do a little digging (whether it’s with a soil auger or just your everyday trowel). Your work will pay off when your new plants thrive in their new home, turning your yard into a beautiful green oasis!


P.S. Want to learn how to improve ‘new development’ soil? Check out this blog post by LEAF.