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freedm2
04-16-2008, 09:43 PM
I just got 15 yrd of tripple ground (very fine) bark mulch. I spread it over the weekend and now any plant/leaf that it touched is brown. Some mulch even got on the grass and it looks slightly burned too.

The mulch was warm when I got it, it rained the night before. Is this just from the heat of the mulch?

shovelracer
04-16-2008, 10:37 PM
The mulch shouldnt be smothering the plants or their leaves. The grass will come back if you remove as much as possible, the plants may take longer. The mulch will be warm cause it is releasing energy as it decomposes, much like a pile of compost. Temps can get as high as 140 degrees from what Ive seen. Clean it up if you didnt already and take it as a learning experience.

freedm2
04-16-2008, 10:40 PM
Thanks...

So you think it was the temperature of the mulch vs some type of chemical reaction? The mulch was steaming. I should have though it through before putting it around the plants (Liropes).

shovelracer
04-16-2008, 10:50 PM
I highly doubt its chemical. Heat is normal. On real cold mornings my dump looks like it is on fire cruising down the road with some steamy mulch.

Critical Care
06-12-2011, 02:55 PM
This is an older thread, but I wanted to show some photos of what can happen when hot mulch comes in contact with grass. The mulch is hemlock and was blown in on a fairly cool morning. The thought of some chemical in the mulch did cross my mind at first however I did assume and conclude that the burning was simply from the heat of the mulch. I often wonder what effect may have occurred had this mulch had been blown in later on in the day, but at any rate these lawns recovered after a few weeks.

ed2hess
06-12-2011, 06:22 PM
You are very fortunate to be in a beautiful place like that.....so cool looking compared to what we have. I am surprised that mulch would do that I never seen mulch burn.

White Gardens
06-16-2011, 01:05 AM
I wouldn't call it mulch burn, but that's ultimately what it is.

I would say it's the composting organisms in the mulch couple with the natural tree saps that burned the grass.

Critical Care
06-16-2011, 12:42 PM
I wouldn't call it mulch burn, but that's ultimately what it is. I would say it's the composting organisms in the mulch couple with the natural tree saps that burned the grass.

Uh huh, basically the end result is that the grass was burned by the mulch's high temperature regardless of the composting process. But yeah, we could blame the composting process on bacteria, air, and moisture.

Ed2hass, this is a beautiful area. Lower elevations are high desert while the higher area you saw in the pics is coniferous and about 16 miles from a major ski area. Hard to complain, but then I don't have an ocean view like some have.

White Gardens
06-16-2011, 12:49 PM
Uh huh, basically the end result is that the grass was burned by the mulch's high temperature regardless of the composting process. But yeah, we could blame the composting process on bacteria, air, and moisture.

Ed2hass, this is a beautiful area. Lower elevations are high desert while the higher area you saw in the pics is coniferous and about 16 miles from a major ski area. Hard to complain, but then I don't have an ocean view like some have.

What is brought to my attention is in Pic "1, If you look left to right the grade slopes in that direction.

So, the grass is burnt on the left and not the right. So, my intuition is saying that it's from leaching of water off the mulch and not a temp related issue.

Not trying to challenge your thought, just saying there is a couple other things that are standing out to me.

RigglePLC
06-18-2011, 01:06 PM
In Michigan a couple years ago we had a similar problem. But I thnk the university people thought it was due to acids released during rapid decomposition of the mulch. Did it smell strongly like pickles? They suspect formic and propanoic and acetic acid. Vinegar odor?

Critical Care
06-18-2011, 04:39 PM
What is brought to my attention is in Pic "1, If you look left to right the grade slopes in that direction.

So, the grass is burnt on the left and not the right. So, my intuition is saying that it's from leaching of water off the mulch and not a temp related issue.

Good observation. Unfortunately I didn't take more photos and my memory isn't good enough to conclude one way or another if this could be true. If it is related to leaching of water then I would assume there should be less grass discoloration next to dry mulched areas than by wet areas. For whatever its worth, this same batch of hemlock mulch was used at other places without any problem. And the distributer of the mulch was contacted but was at a loss as to why this would have happened, and of course he didn't believe it was anything in the mulch... which he'd probably say one way or another.

In Michigan a couple years ago we had a similar problem. But I thnk the university people thought it was due to acids released during rapid decomposition of the mulch. Did it smell strongly like pickles? They suspect formic and propanoic and acetic acid. Vinegar odor?

I donít think I ever remember an acetic smell in this hemlock mulch, or any other mulch as far as that goes. Has anyone else witnessed it? Methane?

clcare2
06-18-2011, 05:11 PM
I have never had mulch that didnt smell like vinegar.


We also had this problem after installing a new motor on our turfco edger. the exhaust was directed down and burned the grass.

SoloSulkySurfer
06-18-2011, 05:51 PM
Looks like a buck made a nice rub on your tree in the 3rd pic from the top. lol

Critical Care
06-19-2011, 12:41 PM
I have never had mulch that didnt smell like vinegar.

Maybe I better have my nose calibrated, eh?

We also had this problem after installing a new motor on our turfco edger. the exhaust was directed down and burned the grass.

Maybe you could edge faster. Does that edger have a second gear?

Looks like a buck made a nice rub on your tree in the 3rd pic from the top. lol

Hey, Iím not laughing. Itís tough to take any pics around here where you donít see this type of damageÖ uh, I mean destruction.