If you are wondering how deep a stump grinder can actually grind down to then you have come to the right place. Stump grinders are a fantastic bit of kit for removing ugly or unwanted tree stumps but can be dangerous in the wrong hands.
Generally one of the first questions we ask our clients is, Why do you want this stump removed? This fundamental question helps us to advise on how deep the stump needs to be ground down and how the site needs to be left.
There are definitely some limitations with stump grinders including the type of machine, the access, obstacles or underground utilities. By calculating these factors into the stump removal, we can work out how deep the stump grinder can go. Let’s look at some reasons that stumps may need to be removed in the next section.
Ok, so, say for instance the machine you hire can grind down to a depth of 45cm. That’s a great depth for a stump grinder, most probably a large machine, but do you actually need to grind down that deep?
Let’s give you an example. If you have a tree stump in the middle of a lawn and you would like to remove it to plant some grass seed then you only need to go so deep. According to Munns, 15 – 18cm of soil below a new patch of lawn is more than enough, hence you would only need to grind down say, 20cm to give a generous amount of room. There may also be some surface roots that you would like to grind at the same time but again they only need to go down to 20cm.
Another example might be you wish to plant a new tree in the same location as the existing stump. In this case, you will need as much depth as possible to ensure the tree can be planted correctly and have enough space to spread its roots. Before you do any grinding or hire anyone to do so, question why and how deep you need to go.
Stump grinders come in many different shapes and sizes. They may be handheld, have wheels like a lawnmower or be on rubber tracks like an army tank. Each machine will have different capabilities too. The obvious choice would be, the bigger the stump, the bigger the machine but this is not always possible due to access restrictions or obstacles.
A pedestrian stump grinder like the one pictured weighs around 160kg, is 73cm wide and can grind down to around 30cm. Pedestrian grinders require a fair amount of physical labour but can access most if not all tree stumps. The tracked stump grinder picture weighs around 800kg, is 90cm wide and can grind down to around 40cm. The tracked machine is bigger to maneuver but the machine does most of the work.
Most tree stumps are surprisingly shallow in the ground as they rely on their roots to keep them standing too. Some tree stumps definitely flare out or are wider below the ground but it is very rare for a tree stump to be too deep to remove completely. A common misconception is that trees have a tap root that goes directly into the ground. Put it this way, we have been grinding stumps for over 20 years between us at Proleaf and there hasn’t been a tree stump that we couldn’t grind out completely with a machine similar to the tracked machine above.
There are some things that may stop stump grinders grinding down to their maximum depth so we’ll name a few of the most common ones.
Obstacles around the tree stump. When stumps are up against retaining walls, fences or buildings, it is very hard to get the machine close enough to grind down completely. It can be done in some cases but there is always a risk of damage to the property or damage to the grinder.
Other trees. If you think about a group of trees standing together and there is a stump in the root zone of another tree, our advice would be to take great care in using a stump grinder to remove a stump in this situation. Not only could you cause harm to the other tree’s health, but you may also make the tree unsafe by cutting through its roots.
The last honourable mention we will make about a limitation that can affect stump grinding depth is underground utilities. Pipes and cables are commonly found underneath tree stumps and knowing how deep they are is always tricky. Assuming you know how deep the utilities run underneath the tree stump, this will limit how deep you grind with the machine. If you are unsure in any way what is below a tree stump before you grind it, we strongly recommend hiring a professional stump removal company to carry out these works for you. Most professional stump grinding companies will have several methods of locating the depth of pipes or cables to ensure no danger or damage is caused.
Well, folks, that’s a wrap. How deep does a stump grinder go? As deep as you need it too, as long as the access is good and there is nothing surrounding the stump!