Tree Planting
  Nov 14, 2005 05:16 PST 

I agree. Urban trees are another thing. When you plant something where it shouldn't perform well, maintenance will be necessary. Some trees do better, some do not.

Planting the tree properly probably counts for 95% of it's survivability. I love when I find a sapling growing in the gardens, and it is in a spot that I would like to have a tree. Then there are no cut roots, no stress.

We recently uncovered a Tulip poplar that was buried with 2-3 feet of soil in 1961. We restored the original grade at the root flare. I see trees planted too deeply too often. Most of the time it is done at the nursery. The worst tree I have seen from a nursery had 7" of soil above the root flare. Often these trees appear to be loose in the ball, but it is because there is a bunch of soil on top of the ball that makes it loose. I could go on and on. Select the right species, plant it right, and give it room and water. It's not hard.

Re: Tree Planting   Megan Varnes
  Nov 14, 2005 06:22 PST 


Planting properly is the key.. The trees that I've had problems with at work were the ones that arrived from the nursery buried in several inches of extra soil. There was no visible flare then, and then the "landscape professionals" that planted them put them even deeper in the ground than they were before. Then other "landscape professionals" mulched them in, covering the flare with several more inches of half-composted, dyed mulch. All I can do with these trees is remove the sometimes up to six inches of soil/matted mulch from the base of the tree, hoping to expose even a fraction of the root flare. (And fire the idiots who left me this mess.)   

It's so very rare to see a correctly planted tree anywhere these days. I worry about all the trees that have been incorrectly planted all over, and wonder if future generations will even know how big these trees would have been if someone had taken the extra few minutes it takes to get these trees in the ground properly!

Maybe we should all plant as many trees as we measure...

Meg V
Re: Tree Planting   Kirk Johnson
  Nov 14, 2005 07:08 PST 
And be sure to look UP before planting. That tree is not going to be six
feet tall forever! I always shake my head when I see a mature tree all grown
up into wires or some other obstruction. All it would have taken when
planting is to think a little about how the tree is going to grow over the
years and place it accordingly. A one-time decision of moving the tree 5-10
feet to one side or the other when planting, so at least the leader isn't
growing directly into wires, would be very helpful in many cases.
Re: visit to a national champion   John A. Keslick, Jr.
  Nov 14, 2005 16:35 PST 

Trees don't have root flares. The flare you mention is actually truck tissue and not root tissue. A lot of people don't know that. Including but not limited to product pushers, such as injections.
I have dissected enough trunk flares to except that.

Anatomy must precede physiology.

See that becomes a real problem when a climber looks at the truck flare and says - OK this tree has root flare and therefore it has woody roots. Their are certain fungi that decay woody root tissues and not woody stem tissues. Therefore you can have a truck flare and no woody roots. Two climbers were killed a tree like that fell. I invite you to see "trunk flares" in the dictionary . Now check this out - You can detect some woody root problems with a SHIGOMETER using the Cambium Electrical Resistance Probe testing trunk flare compared to the reading at breast height (BH) on the trunk. I did it at Tulane University on live oaks in New Orleans. The trunk flares had less resistance then at BH. Where there was known mechanical injury to the woody roots, the resistance increased of the trunk flare compared to BH.

And I do agree with you that trunk flares being buried is a serious planting problem and I also agree with you that many problems for trees start in the nursery.


John A. Keslick, Jr.
Re: tree planting   Lee Frelich
  Nov 14, 2005 17:47 PST 

Meg, Scott:

We have a lot of dying trees in the Twin Cities because they were planted
too low. It is especially bad in urban soils, where compaction adds to the
lack of oxygen that the roots get when planted too low. Even the
University of MN nursery has planted trees too low on campus, and the urban
forestry club has gone around and dug out the root flares to demonstrate
how the trees were not properly planted. This is supposed to be a place
where people learn how to do things correctly, and we hope the nursery
learns from their mistakes.

The Minneapolis Park Board Forestry Department owns all of the planting
spaces between the sidewalk and street throughout the city, and they began
planting all trees at the proper depth 20 years ago! The streets look
really nice in Minneapolis, although we have to plant a lot of new trees to
replace the ones taken down by derechos and tornados (at least 20,000 per


mulch and root flares
   Nov 15, 2005 07:25 PST 

I would urge caution regarding the depth of mulching over the root systems of
trees. Too much of a good thing can be a bad thing!

The natural mulching that occurs in a hardwood forest appears to be just a
light covering as degradation of leaf crops apparently keeps the organic buildup
to a minimum.

However, in the Cross Timbers forests (N. Central Texas) we do see a buildup
around the base of the trunks that may cover the root flares... a slower leaf
degradation due to our lower annual rainfall rates/higher temps. The more
dense stands of Post Oak (read: no wind penetration) will then have varying amounts
of trunk tissue (on and above root flares) degradation due to this organic
material accumulation. In a severe drought year, such as we are now
experiencing, we are seeing a large number of these P. Oaks dying, caused by tissue
degradation or "biological girdling"... a process that gradually affects the health
of root systems. Poor root system + drought/heat = death.

3-4 inch depths of mulching... when that mulch gets dry it repels water and
conversely, it impedes the necessary drying of soils. This situation in new
landscapes, is a tree and shrub KILLER. Soils are very dynamic in that they are
like a bellows in their wetting/drying process. All too often I discover highly
anaerobic soils developing new-site landscapes and well as on re-developed
sites, in part due to excessive mulching.

Additionally, thick mulch layers over established trees tends to invite
upward development of tree roots that are then more susceptible to damage from
cultivation and even drought-influences. These new upper level roots can also be
the precursors for girdling roots of root flares and lower trunks... mimicking
the pervasive problem that tree growers foist upon the public.

My grandfather taught me about root flares & proper planting depths, in the

It has amazed me that:
there appears to be little or no research as to how the tissues change from
aerial trunk tissues to root tissues.. at least I have had no success at
finding such research... even from Alex Shigo
authors of textbooks/ "how-to" books and horticultural professors, have
failed to address the need for exposed root flares... until the last 4-5 years,
when Dr. Tom Smiley (Bartlett Labs) began re-inventing this "wheel" with the
advent of the AIR SPADE.
Root flares... an old established & definitive term. But then, I once heard a
female arborist who said that she wanted to change the term, "limb crotch" to
"limb fork", because she thought the word "crotch" was offensive. What would
she call a "manhole cover" (hahaha)

G. Sandy Rose, RCA
Registered Consulting Arborist
Shade Masters, Inc.
Arlington, Texas
RE: mulch and root flares   Robert Leverett
  Nov 15, 2005 08:11 PST 

Sandy, John, other arborists,

   This is really great stuff. I have long hoped that the arborists in
the list would come forward and enthusiastically discuss tree
maintenance, tree diseases, planting cycles, etc. and educate the rest
of us on arborculture.

   The ENTS list goes through phases of concentrating on tree measuring,
historical documentation, forestry, forest ecology, and a host of
miscellaneous topics to includes some poetry, but seldom do topics
concerning tree diseases and maintenance get aired, beyond an isolated
e-mail. I hope you all will continue.

   I was very interested in you all taking to task the mulching maniacs.
I am also a little surprised at how basic lessons in tree care seem to
have been forgotten. John Keslick, Jr.s emphasis on the importance of
tree biology really strikes a resonant chord with me. The view of a
tree as a long-lived organism that responds to its environment over time
in many predictable ways, thus allowing us to care for it properly,
stands in opposition to the short term view of a tree as a faceless
member of a tree farm or as a hands-off organism in an old growth

   A question I have long had is: which species are most tolerant of
soil compaction and which species are most sensitive? Are there any
rules of thumb to use?

RE: mulch and root flares
  Nov 15, 2005 09:56 PST 

Soil compaction is basically an oxygen deprived environment. The trees I have found to work are those that grow naturally in wet areas, another oxygen deprived area. Sycamore, red maple, pin oak..... It is not that these trees need alot of water, it is that they do not need alot of oxygen to the roots. They grow in the wet places due to lack of competition from trees that need the better ground.
That ought to get things started...

Re: mulch and root flares
  Nov 15, 2005 12:28 PST 

Manhole cover!!! LOL

Seriously. mulch is a killer, especially non bark mulch. Consider that the steam that comes off a pile of "fresh" mulch is wood alcohol, an extremely flammable substance. A few liquid ounces can kill a human if ingested. If there is wood in the mulch, not to be confused with bark, the wood will pull available nutrients from the soil to decompose, therefore robbing the mulched plant of food. I mulch with pine bark nuggets. They are 90% lignins, and don't break down too much. Mulch is strictly ornamental in my book.

RE: Trees and pavement EXCAVATION   Will Blozan
  Nov 15, 2005 12:51 PST 

What is the point in excavating a tree after over 40 years of being buried?
I would think the tree would have long since adapted and invaded the fill
soil with new rootlets. Seems like you would be removing the entire root mat
since the roots at original grade would have died long ago from suffocation.
Do I understand the scenario correctly?

Will B
RE: Trees and pavement EXCAVATION
  Nov 15, 2005 14:20 PST 

The excess soil creates a girdling effect on the trunk that is buried. As someone else mentioned the tissue of the trunk cannot stand being buried, so it rots, and eventually girdles the tree below grade, out of sight. The roots on this tree did rebound, but differently than I have seen in the past. Often times a tree will send out new roots closer to the surface, and abandon the deep ones. The deep roots begin to rot, and the fungus kills the tree from the bottom up, again, out of sight. This tulip did not have any black rotting roots when we uncovered it, nor did it have a new set closer to the ground, so I think it may make it. I can send you a pick of the before and after. Only time will tell if we did the right thing for the tree.

roots, mulch, paving & soil compaction
   Nov 16, 2005 12:51 PST 

Holy moly! I got caught up with dwelling upon the possibility of a
politically correct term for "manhole cover", and I failed to emphasize that mulch
should be, ideally, composted and course-textured.

Composted woodchips are a marvelous resource when used to de-compact soils
when applied in 1-2 inch layers... sometimes, in conjunction with physical
aeration with an AIR SPADE and/or high-pressure tree feeding probe.

What trees tolerate compacted soils and paving? Answers will no doubt vary by
geographic regions as soils and climates can be an influence.

In the Texas, Live Oak (Q. fusiformis/virginiana) is nearly the most tolerant
tree when it comes to soil compaction, drought, paving, & soil fill, but it
is intolerant of excessive soil moisture. American Elm and
Hackberry/Sugarberry, Bois d' Arc and Cedar Elm (U. crassifolia) would follow Live Oak in
tolerances. Bald Cypress can do pretty well if the soil is not too alkaline, but it is
mostly likely to lift covering/adjacent pavement/walks/curbs, as it will
develop "knees" in poorly aerated soil.

"Red Oaks", in our area, are THE most sensitive to root zone changes... cuts,
fills, paving, and wet soils. These would typically include Shumard, Water,
Willow Oaks. They are also higher-risk candidates when transplanted into heavy
clay soils & at high risk of infestation by borers.

Trees installed into vaults in paved areas tend to explore what is available
to them, but, in truth, they really become "temporary" trees. Their root
systems may actually fill the available space, and compress the soil to a point
where the soil will not hold moisture. This can also be the case with trees grown
in large boxes or tubs.

In hindsight, I regret that I have not written down the upteen "old wives
tales" that encompass tree roots, as they would have made a very interesting
book! ... tap roots grow 40 feet deep... roots seek water... roots are only under
the canopy... you cannot plant trees within 50 feet of a foundation... roots
grow straight down... you cannot transplant Post Oaks.... Folks in rural Texas
tend to anthropromorphize trees and their components.

I once saw Post Oaks dying 300 feet upslope from a pasture where Velpar
herbicide was applied to kill Mesquite stumps. We may never know, or have the
ability to determine, how far roots range from a given tree.

I have also seen Live Oaks killed where herbicide residue was washed , by
rainfall, across a parking lot from a railroad ROW... the tree roots were
apparently under the concrete at a range of 150 ft. +, from the trees, and the
diluted chemicals seeped into the expansion joints.

It appears that, the condensate resulting at the interface of the subsoil and
bottom of the concrete, is adequate to support some tree species. Also, air
apparently does infiltrate the expansion joints and perhaps some rainfall.

The never-ending disagreement between structural engineers and arborists over
tree roots damaging house foundations. I have seen massive root invasion and
foundation lifting due to roots (Live Oak) following the original sewer/water
trench under an engineered slab foundation. These trenches are never compacted
and therefore, appear to be reasonably aerated and moist. The small roots
infiltrate the boundry between the slab and pad soil and when they expand
diametrically, they act like a jack.... amazing stuff!

Tree roots are THE most important part of a tree and the part least

G. Sandy Rose, RCA
Registered Consulting Arborist
Shade Masters, Inc.
Arlington, Texas