I have heard so many different theories at seminars about root pruning can anyone shed any light on the following scenario? I realize that when a root is cut it makes it susceptible to disease and decay not to mention creates a potential hazard, does anyone know what effect removing surface roots has on a tree. I have London Plane Sycamores with extensive surface roots radiating in all directions, it is in the turf in a heavily used area. They want the surface roots removed. Are there enough roots deeper (3' or less) that the tree will still be sufficiently anchored ?

Reply to post by JOHN DAVIS, on February 25, 1999 at 11:18:47:

It has been my experience that all trees will remain surface-rooted if there is an impenetrable soil horizon- whether from water table, caliche, or whatever.
But some trees put out surface roots in nearly any condition: sweetgum.
Cutting the surface roots away could leave the tree susceptible to windthrow, depending on the species, and the soil conditions.
The Arboricultural Journal had a piece on rooting styles within the past 2 years, and The Body Language of Trees discusses same. But that particular species, and that particular soil?You will probably need to hire a helper with a short back and dig for a few hours to answer these questions. Charge at least $625 to find out the answer.

Reply to post by JOHN DAVIS, on February 25, 1999 at 11:18:47:

It's my understanding that surface rooting is a response to low Oxy. in the soil, that there are lenticils in the exposed roots.

I have had good results with some maples in topdressing with brown soil (black dirt being 100% organic washes away easily) flush to the top of the roots to eliminate mower damage and reduce trip/fall hazards. Tamp the soil lightly and overeseed with a shade tolerant mix. May need 3-4 year maintinance re-do cycle.

Reply to post by JOHN DAVIS, on February 25, 1999 at 11:18:47:

John, my recommendations in these cases depends on the species, soil conditions, and severity of the root problem.

Can you under plant or mulch over the area? Mulching will offer tremendous benefits beyond covering the exposed roots (like less lawn to mow- my favorite benefit, if I have to mow it [g])

If the species is one that commonly develops surface roots, does it have a deeper root system? Will the removal of some roots impair vigor? If these roots are not the main supports for structural stability, removal of a few at a time may not significantly harm the tree. Consider it much the same as pruning the canopy, in this case. A little at a time, and not large cuts.

Fill soil should be the last resort, usually. If you must use this option, be conservative. Small areas, or dispersed areas around the tree are better. If the roots extend well beyond the fill area, there is usually little risk of permanent damage.

Reply to post by Russ Carlson, on February 25, 1999 at 11:18:47:

Russ, You say fill should be a last resort, but is raising the grade to a level near flush, but not covering, the surface roots going to change the environment too much? This is usualy no more than 2 in amd mostly less than one in my experiance.

Reply to post by John S, on February 27, 1999 at 23:43:18:

The amount of fill toleratd again depends on numerous factors. Sycamores, being able to tolerate low oxygen in flooded areas, may be able to stand a bit more than other trees. The texture of the original soil and the fill will make a difference, too. Heavy clays obviously impede water and gas exchange.

It is not the larger roots you have to worry about. It is the fine absorbing roots. These are subject to the changes in condition in the soil. If you lose a lot of the fine roots, infection can progress into the large roots, and the whole tree suffers. If you limit the area of fill, the larger transport roots can reach beyond the fill soil, and keep sufficient fine roots alive that the whole system survives.

As Ben Franklin said, "Moderation in all things."

Reply to post by JOHN DAVIS, on February 25, 1999 at 11:18:47:

Whenever a question is posted about a particular situation, it is interesting to see how the others involved in the discussion look for clues which were omitted, then answer based on their closest matching experience or their best guess about what may actually be going on in some remote place.
I find myself wondering what kind of heavy use the turf gets: athletic field? footpath?
I wonder what kind of watering the trees get which may contribute to surface root exposure.
I wonder how big the trees are and how large are the roots in question.
I wonder if the root pruning in mind is a careful selection of prominant toe stubbers, or a general clearing of all-size roots visible on the surface.
Basically I wonder why the roots present a problem to anyone, which couldn't be solved by keeping use under the trees to a minimum.
And I wonder whether any "solution", whether it be fill soil or root pruning, really addresses both the underlying stimulus to the tree presenting surface roots, and the best interests of the tree.
Many times I have seen how trees are used with little regard to their needs. If the tree's roots are in our way, then we may have a conflict between the tree's and people's use of the same area.
I heartily approve of planning that reserves trees the space to grow, including their roots.
I also like the recovery of existing tree's root space through the diversion of traffic and the use of cushioning mulches.

Reply to post by Mark Goodwin, on February 25, 1999 at 11:18:47:

Mark, your points are well taken, especially the ones about diagnosing from a distance. We do tend to assume we are talking with other educated and qualified arborists, I think, so offer tid-bits of insight that may help. But you are right- we tend to think according to our our patterns of experience.

Reserving space for the trees, either through advance planning or reclamation of the area is laudable- where it's possible. unfortunately, it isn't always that way, and we must seek the compromises. Much better to mulch than root prune, of course. But if the owners/managers won't approve mulching a large area, we may be stuck with trying to make the best of the situation.

Reply to post by Russ Carlson, on March 03, 1999 at 18:44:18:

Ben was supposed to say, Moderation in "most" things.
With conifers, large roots can rot even as fine roots thrive. Can't say that for sycamore, never having studied it, and I do believe that jumping from conifers to hardwoods stretches the scope of inference. I suspect it is the same story, though, just a little better at forming boundaries to decay.

Reply to post by Mark Goodwin, on February 25, 1999 at 11:18:47:

Thanks for a well-prepared expression of thought. Well said.

I am new with this forum (my first)and will probably write something out of line. But I truly enjoyed reading your comments and liked your way of thinking as evidenced in your comments.

Keep it up!

Reply to post by Peter Torres, on March 04, 1999 at 00:00:25:

I'll look for Ben's quote [G].

My comment was that we needn't worry about the larger roots. I didn't clarify that that was directed at the specific situation of the problem at hand. A small amount of soil over a limited root area has much less impact on the larger roots. Some oxygen is translocated through the roots, and over short distances probably suffices for root function. I have excavated roots of both deciduous and conifer trees where fill had reduced fine roots to near zero, but the transport roots appeared healthy. I imagine more fill, or over a larger area, the results might well be quite different.

Reply to post by Russ Carlson, on March 10, 1999 at 01:02:32:

Russ, I didn't mean you misquoted Ben Franklin. It's just that- "Moderation in all things" doesn't sound very moderate, does it. Peter

Reply to post by Peter Torres, on March 14, 1999 at 21:05:57:

Well, to clear it up, from "The Autobiography of Benjamin Franklin"

9. MODERATION. Avoid extreams; forbear resenting injuries so much
as you think they deserve.

[From his list of proposed 'virtues' to which he endeavored to ascribe.]