Vertical mulching

[Rob Shauger]

Anyone ever try it? Great results.

 

[Jay Banks]

I had the park folks use it on some of the maples in the median of the parking lot. Leaf size and color increased, stem elongation increased so I'd say in an un-scientific study, yeah it worked.

 

[TREETX]

Yes, I have used it in dealing with "stressed looking" post oaks, Q. stellata, on construction sites. Drainage is a big factor for post oaks and I think vertical mulching is a good prescription for that species.

The trees all looked better in the following years. Not sure if it worked, but they looked better. To say "worked" or "great results" we need to have an objective.

 

[kf_tree]

sorry to sound ignorrant, but what is vertical mulching?

 

[John Paul Sanborn]

Vert Mulching is drilling large deep holes in the dripline and filling with a better soil mix then native.

recently published studies show that it probably onnly has a very localized effect, trenching is better. Air excavation is becoming more prevelent due to it's root freindly nature.

I know a few people that have been doing VM with dry fert for years.

I've been using air excavation, on occation, for about a year now.

 

[Jumper]

I did some this past spring, and was also instructed to put some slow release nitrogen fertilizer in the hole as well. As I had the auger one weekend I also did all my own trees and the result seemed to be excellent.

 

[greenguy]

I have done alot of vertical mulching It works really good on trees with compacted soil. It is alot less damaging than radial mulching. Mulching help with the interaction between air water and soil. I usual use a 3'*3' pattern and fill with pea gravel
It tends to allow air and water flow for an extended period of time. I always pump the area full of arborgreen, I believe dogget is the closest product on the market the is an economical alternate.

 

[MidwestTree]

How deep are you digging?

 

[treeclimber165]

Originally posted by MidwestTree
How deep are you digging?

I don't know how others do it, but I came to the conclusion that I should drill about 18" deep. I came to this conclusion because over 90% of the feeder roots are typically in the top 12"-18" of soil. That depth is fairly constant here in central FL, I imagine it may vary in different areas depending on soil and tree species. Extenuating circumstances may call for a deeper depth, also. Trying to save a tree buried during construction, for instance. If the grade has been raised 6", I'd go 24" deep.

 

[John Paul Sanborn]

Also depends on water table.

I do 1.5 feet too, that is the depth used in most of the studies I've read. Never seen a reason for that though. H have gone deeper on a few with the the air tool, since it is so easy. My thought is that if I can get these columns of oprganic material down below the water table I may be able to wick moisture up to the root zone.

 

[Reed]

In cases where solid rock dictates if there's going to be a drip zone, depth depends on the soil profiles which determine the root preferences.

 

[Stumper]

"How deep?"-14 inches. I find very few to 0 roots deeper than that in my area.

 

[Reed]

Also it seems to appear that trees distressed by any number of factors, mulching in this manner stimulates a response otherwise not seen. You taking a path that in 1983, a critical time in oak wilt's growing virulence, the county agent of Bexar County, Texas (San Antonio) told a conference gathering that mulching and composting for health is useless propaganda. This from a professional and tax-funded information advocate.

Look again closely at the responses, also try it in a controlled fashion, leaving proximity trees alone. Random treatments and gauge it for yourself. The odd things is, knowing about vascular damage to xylem tissues from sterol-inhibiting agents, if chemical intervention has to be prescribed therapeutically, the minimum requirements should also be a provisional treatment to ammend dimished nutritional stresses. I'm not talking nitrogen either.

We're going to step a few rings higher than county agent recommendations. In fact, we're going to where they never think. They don't "do" trees....we do. No offense intended for all the agents out there, but what you guys advised didn't work good enough. It's time to try other stuff instead of just believing it won't work simply because someone told us it wouldn't. Science is increasingly risky, look at the Coho kill in the Klamath.
Yeah...."opps" (Gale Norton on the advice her appointed panel's misjudgement).

 

[FBerkel]

JP,

Are you using the airspade to radial trench? Sounded like maybe you're excavating more than just trenches; if so, are you back-filling with compost, or what?

Thanks in advance

 

[John Paul Sanborn]

For cost/logistical reason I was amending the spoil for backfill with a sandy loam. This because of our heavy clay soils here, and the loss of around 30% of the spoil dirt durring air excavation.

In light of the recent article in JOA, i may recomend total replacment in some cases. Though the volumes are probably prohibative in many cases.

Matt asked me about working on a clump of three maples and doing the pie shaped total replacement recomended by some for construction mitigation we would have had to deal with some 240 yards.

Using radial trenches of 2 foot width and amending the spoil would result in needing around 40 yards of new soil.

Some of Smiley's studies show that there is not net longterm gain in aeration if there is no amendment.

I think the introduction of native macrobiota to help with the mixing the soils better would help. I've read that there can be discontinuites with hand mixed soil.

 

[Kneejerk Bombas]

John wrote:
"Some of Smiley's studies show that there is not net longterm gain in aeration if there is no amendment."

That's interesting. It seems that aerating the soil would take care of compaction, unless soil compaction was not the problem to start with, or unless the soil gets recompacted.
Could you elaborate more on the subject?

 

[John Paul Sanborn]

There as no net increase in porosity after air fracturing several months down the road. I think this was an evaluation of that compressed N system we have been seeing advertised for a while. I remember mention of some other similar test.

There was no position as to why this occured.

Might be that it is still too much of a microscopic event, and maybe composition is involved too. We need the worms to crawl in and out for 5 years (this is an average figure I have seen in a few places) for tru reliefe of compaction.

introduction of organic mater increases the populations of macrobiota...