Planting in a spot that a stump grinder has been through

[miamicuse]

Can something else be planted in the same spot where a previous large tree was cut down and a stump grinder have been through?

I have a few areas where there was a fairly large tree previously there, but was cut down due to either disease infestation or hurricane destruction and was removed.

One example is a 50' tall royal palm with 22" diameter at the base suffered from the deadly ganoderma butt rot in 2020, and was removed.

Then about six months later I had the stump grounded about 10" deep.  I removed most of the chewed up pulpy materials and put down sand/soil.

Now, in 2023, I can still feel when stepping on it it's kind of spongy.  The previous root mass will continue to break down and this will be a long process.

Will the ground here ever be stable enough to plant something else substantial besides ground covers or small shrubs?

I have another spot where I had a 30' tall mango tree that was down by hurricane Irma in 2017.  Did the same, removed tree, stump grinded, and my wife planted the same mango tree (a baby version) in the same exact spot despite my warning.  That baby mango tree grew to about 7' tall and last week we had a non-tropical storm with gust of 75mph and the new tree was flattened to the ground, I think because it's root cannot get a solid grip on the soil due to the soil is filled with the decaying roots of the previous mango tree.

[miamicuse]

saw on Youtube that someone says drilling deep holes into the roots and adding Epsom salt will accelerate the disintegration of the roots.  Others said to pour gasoline into the hole and set it on fire...I am not sure about that.

[Silas_Sancona]

40 minutes ago, miamicuse said:

saw on Youtube that someone says drilling deep holes into the roots and adding Epsom salt will accelerate the disintegration of the roots.  Others said to pour gasoline into the hole and set it on fire...I am not sure about that.

Either can work.. though if using something flammable you'd only drill holes about a few inches deep, pour said gas / lighter fluid in the holes, let dry for a day, then repeat again. Have to allow the fluid to be absorbed by the woody material for the roast to work.. 


...When ready to burn, you'd place a layer of charcoal atop everything and set on fire.. If done right, Stump will slowly burn w/ very little flames / smoke.  Solid stump that glows bright orange for several hours is kind of neat, imo..  Did that with the stump of a tree i took down in the old yard here and it worked. Burned out everything, even bigger roots below ground leaving only a few small roots that were easy to remove later.. Planted right over it a year or so after i removed the original stump.

That said, FL isn't AZ and even here, if your " Stump Roast "   produces a ton of smoke, Fire Department could show up at your door and you could get into the weeds regarding whether or not you were allowed to burn the stump in the first place.  Not sure if burning out a Palm trunk would behave the same as roasting the stump of a woody tree either.. Don't think there would be a difference in how it burns, but, you never know.

Epsom salts, a form of Potassium, which is what many " Stump Remover " products are made of will work to break down the stump too

..but will take longer to do so, probably less time there since your weather stays wet, hot, and humid this time of year.

[iko.]

On 11/21/2023 at 5:07 PM, miamicuse said:

Can something else be planted in the same spot where a previous large tree was cut down and a stump grinder have been through?

Yes, but I think is important to keep the area well watered. The remains will decompose over time and in my opinion, it will facilitate newer roots to establish. Luckily, I didn't have big problems with the wind but maybe it's because, most of the times, the new plants have become bigger than the previous trunk. 

I have planted this way...

- Archontophoenix practically on top of avocado tree. For the first 5 years or so the old avocado stump made some big solid fungus (sorry, I don't know the name for these) which were growing right at the base of the Archontophoenix. This year I discovered the old avocado trunk and roots have disappeared completely leaving a hole as long as the arm. I filled this with soil because it went below the Archontophoenix trunk.

- Roystonea on top of old Washingtonia. Old remains of Washingtonia become soft, similar to a cushion or dry algae at the beach. If you walk on top you can easily sunk a few centimetres. With this one, the stump left by the Washingtonia is much bigger than the new Roystonea trunk. 

- Mango on top of olive tree, took a bit longer for the mango to establish though. I will say a couple of years with no much significant growth.

- Roystonea on top of cherimoya, no problem. 

- Ravenala on top of dead Ravenala attacked by bacterial disease. I was concerned of the possible bacteria left in the soil so I wait one year. New plant is growing well but I have some poles to keep it still as it's not that secure yet when windy.

I do often plant on top or next to old Ensetes but those are softer than the previous plants I have mentioned.

[miamicuse]

It's been four years so I figured the palm roots will be significantly broken down and softened that I can excavate and plant something else in this spot, but it's not.

So a quick recap.

In June 2020, the 24" diameter 50' tall royal was IDed to have been infected with Ganoderma butt rot.  In July I had it cut down to the ground level.

16 months later in November 2021, I hired a tree service to do a stump grinding down.  The operator told me the machine will grind down 10"-12", but a lot of mulch was generated in the process it was impossible to see how deep it got.

Now in May 2024, 4 years after I cut it down, 2.5 years after I did the stump grinding, I started to excavate the hole, took out all the mulch form the stump grinding, until I met resistance.  Once I cleared everything out, basically what I have is a giant round shaped "wood bowl", about 24" in diameter, and 6" deep in the middle.  I put a pointed shovel to it, and a breaking bar, no give at all, rock solid.

So I am thinking, if I want to plant something in this spot, and I do have some long 18" wood bits, if I can drill down through the root mass many holes along the 24" circle, may be I can pry out this "wood plug"?  How deep do you think this roof mass is?  Will it be a futile effort?

Now you may be thinking why not just leave it alone and find another spot a few feet over?  I could I guess, but this is actually a really good spot.

[Brian]

When I first bought my property here in Mexico I planted Cocos and Roystoneas around the whole property about 1 meter inside the property line. After about 15 years they got so big, they started dropping cocos and fronds on the neighbors yards and driveway so we ended up removing several of them over the years. We cut them down with scaffolding and dug out the remaining trunks by hand, no easy task but it can be done. Every removed palm was replaced with much more manageable plants which are thriving. I only left two trunks in the ground because they were too close to palms I didn’t remove. Of those two trunks, one has already decomposed to the point of it being easy to remove, which took about 5 years and the other I use as a pot stand for a cycad. 
The mass of the trunk base is maybe a meter deep. The roots grow our laterally so once you get down to that depth it’s fairly easy to get the trunk base to move although it’s extremely heavy. We usually split the trunk base with an ax and breaker bar into more manageable pieces once we get through the lateral mass of roots. You can cut through the root mass with the sharp flat end of a pick or an ax. 
With one or two guys helping me, we could usually remove a trunk base in about 8 hours. It’s very hard work but doable. 

 

[Merlyn]

I'd agree with @Brian on the trunk and root size.  I found that if I go outwards a few extra inches it gets into looser roots and it's easier to cut through with a shovel or reciprocating saw.  Then just dig around until you get the entire perimeter of the "plug" of root mass.  I plan to do this with a Queen that caught Thielaviopsis.  I cut out the main trunk and RIZ area with a reciprocating saw (Bosch RS325) and 12" Diablo carbide 3TPI pruning blades.  That's about $110 for the saw and a blade, but it'll cut through the roots like buttah!  Go around the outside perimeter with the saw, then cut the center bowl into pie shapes, and pry out with a shovel or pry bar.  It's annoying, but I pulled out several smaller trunks in about an hour.  I'd guess a couple of hours on a big royal trunk, especially in this heat!

[miamicuse]

6 hours ago, Brian said:

When I first bought my property here in Mexico I planted Cocos and Roystoneas around the whole property about 1 meter inside the property line. After about 15 years they got so big, they started dropping cocos and fronds on the neighbors yards and driveway so we ended up removing several of them over the years. We cut them down with scaffolding and dug out the remaining trunks by hand, no easy task but it can be done. Every removed palm was replaced with much more manageable plants which are thriving. I only left two trunks in the ground because they were too close to palms I didn’t remove. Of those two trunks, one has already decomposed to the point of it being easy to remove, which took about 5 years and the other I use as a pot stand for a cycad. 
The mass of the trunk base is maybe a meter deep. The roots grow our laterally so once you get down to that depth it’s fairly easy to get the trunk base to move although it’s extremely heavy. We usually split the trunk base with an ax and breaker bar into more manageable pieces once we get through the lateral mass of roots. You can cut through the root mass with the sharp flat end of a pick or an ax. 
With one or two guys helping me, we could usually remove a trunk base in about 8 hours. It’s very hard work but doable.

A meter, wow that's deep.  I was contemplating taking an 18" long wood boring bit and drill down to see if I can get past the root mass.  But if it's a meter down it will bottom out and only be half way through.  I am near a river and water seeps in at 22" below so anything more than that I wouldn't be able to see anyway.  I thought if I can drill and find the bottom I can do 24 holes down like around the clock and get it out that way.

[miamicuse]

5 hours ago, Merlyn said:

I'd agree with @Brian on the trunk and root size.  I found that if I go outwards a few extra inches it gets into looser roots and it's easier to cut through with a shovel or reciprocating saw.  Then just dig around until you get the entire perimeter of the "plug" of root mass.  I plan to do this with a Queen that caught Thielaviopsis.  I cut out the main trunk and RIZ area with a reciprocating saw (Bosch RS325) and 12" Diablo carbide 3TPI pruning blades.  That's about $110 for the saw and a blade, but it'll cut through the roots like buttah!  Go around the outside perimeter with the saw, then cut the center bowl into pie shapes, and pry out with a shovel or pry bar.  It's annoying, but I pulled out several smaller trunks in about an hour.  I'd guess a couple of hours on a big royal trunk, especially in this heat!

Unfortunately reciprocating saw around the perimeter is not an option for me because whoever originally planted the royal had a thick layer of round pebbles (some the size of an egg some the size of baseballs) around the palm and as it grew the roots tangled with the pebbles they then piled mulch over it and so any reciprocating saw just hit and bounce off the deeply buried pebbles.  I tried to free up the pebbles but they are so tangled up and deeply buried I say I have a layer of at least 4 to 6 inches of these pebbles and around the edge of the hole they are sharp due to being chipped by the stump grinder.  I may need a napalm in that hole!

[Merlyn]

@miamicuse you could get a 1" diameter 12" long forstner drill bit and drill a big hole in the center.  That would give you a starting point to put a reciprocating saw blade down in the middle...then cut outwards into pie shapes.  You could even cut in a big circle in the center (maybe avoiding most of the rocks) and cut out a plug from the middle.  Even if you trash the blade completely, or don't get all the way out to the edge, it might allow you to get a digging bar or "pinch bar" down into the gap and start prying pieces out.  I have a 60 inch 18lb pinch bar for stuff like this:

https://www.harborfreight.com/18-lb-pinch-point-bar-95971.html

I'd guess a big chunk of steel from Harbor Freight might be ok...everything from there eventually turns into a hammer and it's already kind of a hammer! 

[Brian]

@miamicuse My trunk bases might have been up to a meter deep but the majority of the root mass was shallower. The key is cutting through the root mass. I too had lots of cobblestones mixed in with clay which is why the pick ax with a flat end worked best in my situation. 
 

[Brian]

11 minutes ago, Merlyn said:

@miamicuse you could get a 1" diameter 12" long forstner drill bit and drill a big hole in the center.  That would give you a starting point to put a reciprocating saw blade down in the middle...then cut outwards into pie shapes.  You could even cut in a big circle in the center (maybe avoiding most of the rocks) and cut out a plug from the middle.  Even if you trash the blade completely, or don't get all the way out to the edge, it might allow you to get a digging bar or "pinch bar" down into the gap and start prying pieces out.  I have a 60 inch 18lb pinch bar for stuff like this:

https://www.harborfreight.com/18-lb-pinch-point-bar-95971.html

I'd guess a big chunk of steel from Harbor Freight might be ok...everything from there eventually turns into a hammer and it's already kind of a hammer! 

I was calling it a breaker bar but I should have said pinch bar. It’s one of my most useful garden tools. 

[Merlyn]

12 minutes ago, Brian said:

I was calling it a breaker bar but I should have said pinch bar. It’s one of my most useful garden tools. 

Yeah, I don't use it all that often...but on big jobs like that it's time to whip that bar out and do some damage.  I used it a lot when splitting up and removing oak stumps.  The other one that's useful (but I haven't bothered to buy one yet) is the post hole digger bar with the tamper on the other end.  The 2.5-3" wide blade is good for splitting up stuff.  I prefer the tamper end instead of the sharp point end, just because I don't feel like accidentally impaling myself.    They aren't as strong as a pinch bar for prying, so I'm not sure which would work better for @miamicuse's royal.  I'm sure a wide blade pick axe would go through the roots pretty well too.

https://www.harborfreight.com/17-lb-digging-bar-with-tamper-93612.html

[Swolte]

Yeah, I've dug out trunks larger than that size and with woody roots. This should be doable with the right tools (digging bar is great and these root slayer shovels are amazing) and patience. If you're not physically fit, do a little bit every day. Treat it like a hour at the gym (and expect to be sore). Once you start, you may notice its not that impossible to dig.

[miamicuse]

On 6/13/2024 at 7:16 PM, Merlyn said:

@miamicuse you could get a 1" diameter 12" long forstner drill bit and drill a big hole in the center.  That would give you a starting point to put a reciprocating saw blade down in the middle...then cut outwards into pie shapes.  You could even cut in a big circle in the center (maybe avoiding most of the rocks) and cut out a plug from the middle.  Even if you trash the blade completely, or don't get all the way out to the edge, it might allow you to get a digging bar or "pinch bar" down into the gap and start prying pieces out.  I have a 60 inch 18lb pinch bar for stuff like this:

https://www.harborfreight.com/18-lb-pinch-point-bar-95971.html

I'd guess a big chunk of steel from Harbor Freight might be ok...everything from there eventually turns into a hammer and it's already kind of a hammer! 

I have forstner bits for woodworking tasks but I don't think I will try it on the palm root because it's has sand mixed in it and will just dull and gum up in no time.  I might try a wood augering bit I have some longer ones 6" 8" 12" 18" even that I can try and see how deep the whole mass is.  With reciprocating saw I don't think that will work either even with a center hole as the blade will most likely just bounce off and bent out of shape in no time unless I cut it at a much shallower angle.  One thing I may try is t drill multiple holes forming a dotted line and see if a breaker bar can cut the remaining material loose.

[miamicuse]

On 6/13/2024 at 10:08 PM, Swolte said:

Yeah, I've dug out trunks larger than that size and with woody roots. This should be doable with the right tools (digging bar is great and these root slayer shovels are amazing) and patience. If you're not physically fit, do a little bit every day. Treat it like a hour at the gym (and expect to be sore). Once you start, you may notice its not that impossible to dig.

I do have various breaker bars and pry bars 5' and 6' tall.  That's what I used initially to try to break the middle of this palm root "bowl" and realized it's rock solid.  I also have a rotary hammer with a SDS+ chipping bit hoping to crush the material but not much luck either.

[Merlyn]

@miamicuse yep those are the two bars I'd think about using, a pinch bar on the left and digging bar on the right.  As a reference, at lunch yesterday it took me about 20 minutes to use the 12" blade reciprocating saw to yank out this 5' trunk Phoenix Sylvestris:

I sliced all the way around it at a slight angle inwards, and got down far enough to be into loose roots.  I had to cut an additional "wedge" shape on one side to get down under the center, then just sliced horizontally as best I could.  Then I just pushed it over and sliced the last couple of stragglers.  It took more time to cut the log into manageable <100lb pieces than it did to slice it out of the ground. 

If you can get a ~12" diameter hole cut in the middle, I think it would be worth trying to drill a hole and sneak in a 12" long reciprocating saw blade.  There probably aren't too many rocks in the middle.

[miamicuse]

@Merlyn how deep is your root mass before the loose roots?

I have no idea how deep mine is.  I was thinking may be 20" to 24" and since the stump grinder has taken out 7 to 8 inches of it that leaves another 16" or so of solid mass to remove.  Two weeks ago I cleared all the dirt and mulch out of the crater and it's really shaped like a solid wood bowl.  I was hoping it's decayed enough that if I repeatedly pound the breaker bar in the middle I would beat it in up but no go it sounded really solid.

Of course there are the small roots radiating out from the edge of the trunk also tangled in with the pebbles those roots are loose and coming apart.

I have to wait a bit before I can try again we just had another massive rain event and the yard again flooded and soil is like a wet muddy sponge.

[Merlyn]

@miamicuse all the ones I've dug out have been solid root masses to around 12-18" maximum.  Around the 12" point they seem to start spreading out to semi-loose instead of a solid chunk.  That goes for 20' tall queens and the 5' trunk Sylvestris I just removed.  I usually end up breaking the tang on the blade before it dulls, at least on the carbide tipped ones.  I'd try drilling a pattern of holes with your 18" bit and then cut between them with the reciprocating saw.  Then pry out with that wide tip digging bar.  That's what I did to remove some 6-10' diameter oak stumps like this one:

And a couple of pie chunks removed:

And the remaining pieces:

Or a whole stump in one afternoon/evening: