The week of September 18, we're launching an all-out assault on
at least four stumps left over from previous thinning operations.
The objective is clear - remove the stumps while minimizing impact to the
surrounding yard areas. In the past, I've used the backhoe to dig
out stumps. That leaves an enormous crater, and it really beats up the
backhoe, which was never designed for such severe service. It is immensely
satisfying, however, to hoist an offending stump out of its socket after a
couple hours of digging and prying with the backhoe.
This time around, I'm going to try a gentler approach that is
gaining widespread acceptance in the tree service profession - using a stump
cutter or grinder to "chew" the stump down below the ground
surface. This is much less intrusive than digging the large crater, and at
least in theory will take less time than digging the stump out with my smallish
backhoe. The stumps to be removed this time are larger and less rotted
than ones I've dug out previously. One of the stumps measures five
feet across! This will be a tough test of the stump grinding
I'm renting a Vermeer SC252 25HP stump grinder in Olympia. The
unit weights about 1100 pounds, and comes on its own trailer. Vermeer
makes top quality equipment - we own a Vermeer brush chipper that has always
served well. You can rent smaller "handlebar" stump
grinders, but they're no match for the five foot stumps in this project.
I'll post daily results from the project, which is scheduled to
be completed by the end of the week. Updates have been posted "newest
to oldest", so if you've been following this project, the most recent news
is right at the top. Scroll down to see the previous days.
Project Conclusion: A 25HP or larger stump
grinder makes possible all kinds of grounds improvements. In the
almost 30 years we've lived here, our clearing, trails, and outbuilding
placement have been constrained by where the stumps are. With a few hours
time, it's possible to remove even the largest of stumps. Grinding the
stumps instead of digging them is relatively non-invasive, which was a key
requirement for getting rid of the two stumps in the front yard that were
positioned more or less between our three lateral septic drain field
lines. Digging them out with the backhoe would have risked disturbing the
drain tile or rock. The larger stumps would realistically require a much
larger backhoe or an excavator, which would mean contracting the work out.
The stump grinder is equipment I can transport and use myself, which makes
scheduling projects far more flexible. There are larger grinders that can
do this job faster, but the 25HP size is easily moved around the property, in
sometimes tight quarters, with 36-48" of clearance all that's
required. I have a long list of other clearing projects that will be made
possible by access to a stump grinder.
Day 7: Sunday, September 24 - unexpected
|Unfortunately, I have no "before"
pictures, so it's a little hard to fully appreciate what became possible
once stumps were no longer the limiting factor. The path to the
right has always been a trouble spot - it's just barely wide enough for a
wheelbarrow, and it's never been possible to get the tractor or other
equipment through here. Armed with the stump grinder, I cleared the
path to the left with the tractor and box scraper - plenty of room for all
of our equipment now.
||The box scraper is a terrific tool for trail
building. Its four drag teeth capture most of the brush, and the
small stumps, while the twin blades at the rear of the box lay the soil
down smooth. The scraper is 48", and all of our equipment will
travel on a 48" patch (excepting the trailer).
||Here you can see where I spread the remnants
of an enormous stump to build the road. The stump was about 50"
at the base, and about 24" tall. All the chips generated from
grinding make nice paving material.
||In the 28 years we've lived here, it's never
been possible to get a tractor down this end of our North fence
line. To blaze this trail, I felled one tree (using the tractor,
wire rope, and a snatch block anchored to another tree to precisely
control the felling direction), and ground out three good sized
stumps. There's plenty of additional cleanup that can be done on the
edge of the trail, but I can now get the tractor and chipper all the way
|This is looking back at the new fence line
||After a little more smoothing, this is the
area adjacent to the house where we plan to put a dog kennel. It 's
amazing how getting rid of the stumps makes a nice, open area.
Day 4: Thursday, September 21
|With the four originally planned stumps now
gone, today I worked on some "extras". This stump by the
equipment shed was forever a pain to mow around. This was another
pretty good sized one - about 48". It was a little tricky
getting this one out because the grade around the stump was sloped about
8" from one side to the other. After grinding it down a ways, I
used the box scraper to drag a new, level grade, then reground the stump
to about 6" below the new grade.
||There was a 30" stump at the base of the
tree whose top blew over onto the house earlier this year. There are
also a couple of much smaller stumps in this area (12" or less in
diameter). The Vermeer made quick work of those - until I ran out of
gas. I'll finish up the last of the little stumps
||Here's a closeup of the carbide
cutters. They have three cutting edges (the cutters can be rotated
in 120 degree increments). The machine was starting to vibrate
- a lot. I found the dullest of the cutters, and spun them 120
degrees. The performance picked up dramatically. I'm
pretty sure this machine could be made to run even better than it does now
by replacing several of the most-worn cutters. That's always the
downside of rental equipment - they tend to run them until they're
Day 3: Wednesday, September 20
The original objectives of this campaign have been met!
|This is the smallest of the four stumps in
this project. It measures less than two feet across. The Vermeer
makes quick work of this - the entire width of the stump can be cut in one
pass. I did not have to reposition the cutter. As an
experiment, I started on this stump at its original felled height to get
an idea if it is really time-effective to cut the stump low with the chain
||This is the last stump. It measures a
little over 3 feet. I decided it was best to cut the stump very low
before starting. While the cutter went throw my experimental
"high stump" fast enough, it created an enormous pile of debris
that had to be removed (see later picture). Look at how sound
the wood is in this Douglas-fir stump, some ten years after cutting.
So much for the "let it rot" approach to getting rid of stumps,
although I have seen hemlock and pine stumps that are thoroughly rotted
after a few years.
||The Grays Harbor rain came with a vengeance
today. I managed to get the job done, but the ground was getting
pretty wet and slippery. Raked more or less smooth, it looks pretty
good. It took about three hours to do the grinding, and another
three to do the cleanup and smoothing.
||Here's the enormous pile of stump cuttings
that wouldn't fit back in the hole. I loaded them in the trailer and
will use them to fill in our trails (when we get a little drier
day). Unlike the tree chipper which blows its chips right into the
trailer, there's only one way to get the stump cutter chips into the
trailer - a shovel at a time. That's why I decided to cut the last
stump low before starting - to minimize the amount of debris that has to
be shoveled away.
Day 2: Tuesday, September 19
|Here's the Vermeer SC252 that I rented from
LewRents in Olympia. It uses the same Kohler V-Twin 25HP engine that
is on our Vermeer wood chipper. This is industrial-strength
equipment that's a delight to explore.
||The cutter wheel is 1/2" thick, 16"
diameter. The 16 carbide cutters form a 19" circle
tip-to-tip. Hydraulic cylinders raise and lower the cutter
wheel, and move it from side to side. The side to side
"sweep" rate is automatically restricted to keep engine rpm up
as the load increases.
||Here's what the larger stump looked like
after I made four passes through it.
|It took about three hours to get to this
point. The stump has been ground down to about 6" below the
ground surface. This very large (5 foot diameter) stump required
repositioning the cutter many times. The biggest challenge was
seeing what was left to cut and confirming the stump depth below all the
debris that was accumulating under the cutter.
||The smaller stump was a much easier
task. It took about an hour and a half to grind this one down.
I only had to reposition the cutter a few times to get it all.
||Here's a more or less finished product.
I've spread the stump chips and back-bladed them with the tractor.
There's more smoothing that can be done, but that can wait until the other
stumps are taken out. Eventually, a dog house (or two) and a fenced
run are going in this new flat space.
||Here's tomorrow's project: The two
stumps in the front yard. One of these is pretty small, the other is
about the same size as the smaller stump I did today. I'm estimating
three to four hours to take both of these out (after an hour or so of
chainsaw work to cut these down to ground level).
Day 1: Monday, September 18
|The first two stumps to go are located near
the house. We're thinking about building a dog kennel in this
area. It's easy enough to make out the large stump in the
foreground. There's also a pretty good sized stump hidden below the
small hemlocks a little further away.
||After several hours of chain saw work, I've
taken the two stumps down close to ground level. This is the first
step in grinding them out - it should be faster to cut out the
above-ground portion than to grind it away.
||One stump measures an impressive five feet
across. This will be the most severe test of the grinding equipment
||The second stump in this area is about half
that size - about 30" across at the ground.
|My chain saw can't cut 5 foot stumps (or
30" ones for that matter) in one pass, so the above ground wood came
out in pieces. Notice how good this wood (fir) looks even after
these stumps have been sitting for about seven years in the
Olympic Peninsula rain. Only the outermost couple of inches were
rotted, the rest of the wood was firm and sound all the way to the ground.