Any type of tractor, even if the brand advertises it for steep hills, should never go over a grade more than 15° to 20°. If you attempt a hill that’s steeper than that, you will roll the tractor. There just won’t be enough power or traction to make it.
However, this is for residential tractors. Commercial and industrial-sized ones can handle a much steeper grade, around 20° to 35°. You should never attempt to use a tractor to mow a hill above 35°. Turn these into wildlife areas or a garden bed. For anything less than 35° in regards to residential tractors, use a push mower.
How Do You Know if a Hill Is too Steep for a Tractor?
Per the American National Standards Institute (ANSI), you should always evaluate a steep slope before you decide to mow it. A good trick is to try and back up the tractor on the hill a little bit to test the grade. If your wheels spin out or you can’t move effectively, avoid using a tractor on it.
Even if the tractor ends up being suitable, you also need to observe the area for other hazards. These will include things like drop-offs, rough terrain, trees, holes, ruts and other such things. Plentitudes of rocks and sticks will also present potential dangers. Always remove large debris before mowing with the tractor.
How Do You Determine the Steepness of a Hill?
To determine how steep a hill is, you will have to do a little math. Take two wooden stakes, a hanging bubble level and some rope. Put a stake at the top and bottom of the hill. Then, attach the rope and use the level to align it with the tight, level line with the rope.
From here, measure the height of where the rope touches the stakes. The difference between these is the “Rise.” Then measure the rope’s total distance, or the “Run.” When you have these numbers, you can use the following equation to figure out the hill’s grade:
Rise x 100% ÷ Run = Hill’s Grade (also called Slope)
Why Can Residential Tractors Only Mow Up to 20°?
Residential tractors are ideal for steep hills that have a grade up to 20° and even this number is on the higher end of things. Generally, it’s much less than this, 15° grades are much more common for a tractor. This is because of how the machine’s design is.
The engine, horsepower and transmission will all come into play. For instance, even if you have a V-Twin with 24 horsepower and hydrostatic transmission, the wheels won’t get enough power to make it up a steep hill beyond 20°. This will be especially true if the hill is wet.
Why Shouldn’t You Use a Tractor to Mow Grades More than 35°?
When hills are steep, it increases the risk of flipping, tipping and rolling. This can seriously hurt you. Indeed, cases of death as a result of tipping are not uncommon. In fact, in 2007, there were 61 deaths and 15,000 serious injuries. These included broken bones, dislocated spines and brain damage, among others.
Why Are Commercial Tractors Better for Steep Grades Up to 35°?
Most commercial tractors can handle steep grades up to 35° because they have a feature called a ROPS, or rollover protective structure. Plus, they also have safety seat belts. Both of these work in tandem with one another to secure and protect the operator.
As a result of the design, engineering and these safety features, death and injury are far less common. Even if the tractor tips over, the most of the damage will happen to the tractor and not the person inside. But, these are hugely expensive and not pragmatic for residential use.
What Is the Best Tractor for Mowing Steep Hills?
The best kinds of tractors for mowing steep hills should have front-end power steering with a rear engine. This will provide traction, safety and keep you upright the whole time you’re mowing. However, there are a few specific brands of tractors that are most ideal for hills.
For instance, Husqvarna, John Deere and Craftsman will produce the most reliable tractors that can handle steep grades. Consider the brief overviews below:
TS 354XD by Husqvarna
This tractor by Husqvarna has 24 horsepower in its fantastic Kawasaki engine with a displacement of 726cc. It’s easy to steer with reliable and durable construction. They designed this particular tractor with the average homeowner in mind who has a wide range of terrain to deal with.
According to the owner’s operation manual, it can handle a grade of no more than 15°. But this is average for most backyards. Regardless, it has a 54-inch mowing deck with adjustable height and speed control. It has ground-engaging transmission so that it will give you the best grip possible up a hill.
S180 by John Deere
As the Lamborghini of tractor brands, the S180 by John Deere allows for a fast mowing time and makes quick work of hills, slopes and steep grades. The owner’s operation manual suggests using this on hills with no more than 15°.
The S180 has a 54-inch cutting deck with triple blades that are adjustable. It can handle a variety of tasks due to the power and torque this piece of equipment offers, although advertised as a riding mower. It has a V-Twin engine with 24 horsepower and a displacement of 724cc.
T3200 by Craftsman
Also recommended for grades of up to 15°, Craftsman’s T3200 is ideal. It comes with a 24 horsepower Kohler 7000 series front engine that has a displacement of 725cc. The cutting deck is 54 inches and has several adjustable heights with three blades.
The tires and transmission will make cutting steep hills a breeze. Its construction and materials are reliable, durable and powerful. You can even use it on hills that are somewhat wet with peace of mind.
Hi, I’m John Stephens, chief editor and writer for Totalgardener.com. I’ve been gardening and raising animals for over 15 years starting with a small backyard plot in Northern Virginia where I grew corn, potatoes, squash, and using a high mulch technique called the Ruth Stout Method. I also raised ducks and small mammals for meat and eggs in a movable pen similar to the ones used by Joel Salatin. I later moved to Colorado where I experimented with growing greens using aquaponics inside. I eventually added a microgreens setup and home sprouting operation. I’m excited to share everything I’ve learned plus more from the other local gardening and animal raising experts I know.