Stem Griddling Roots After Raising Ground Level?

[Nehmo Sergheyev]

I have a cherry tree with a three inch (? 80 mm) trunk, and I want to landscape the ground upward around the trunk a couple of feet (? 60 cm).

I just learned about Stem Griddling Roots (SGR)

this isn't a tree fresh from the nursery, raising the ground level may give the roots an opportunity for SGR. Are there some precautions I should take? Should I surround the trunk with something? If so what could it be? It would have to accommodate the trunk growth yet prevent the roots from encroaching.

[Travis]

Do you mean you are going to put a couple of feet of soil on top of the ground where the tree is planted? That will kill the tree for sure.

[Nehmo Sergheyev]

- Travis -

Yes, that's what's going to happen. I didn't know it would kill the tree. Are you sure? Why would it?

[Peter Jason]

[figaro]

Most feeder roots for a tree are in the top 6 -12 inches of the soil. Many soil nutrients remain in the top few inches of soil due to the inability of the molecules to move through soil. In fact, if potassium and phosphorus containing fertilizers are not dug into the soil about 6 inches, they are unavailable to the plant. The roots also require air to function properly. It is the moist air between particles of soil that allow moisture to be taken up by the root system. Most people think of roots as something that sucks up water like a straw but that is not how water molecules are transfered into plant tissue.

By piling two feet of dirt on top of a trees established root system, you basically suffocate and starve the tree before it has time to put new roots up to the surface where they can function properly. It is common horticultural practice that the soil level around established trees NEVER be altered. This is why you see some trees with a deep well around the base. In that instance someone has needed to raise the soil level and has protected the tree by keeping the soil level adjacent to the tree at the lower level while the rest of the land can be regraded to the new higher level.

Maybe this would be a solution for you? I didn't catch why you wanted to raise the soil level but putting a well around the trunk of your tree will allow you to raise the soil levels in the rest of your garden higher. Just remember to allow enough space between the well and the trunk so that the surface feeder roots have enough area to prevent suffocation.

[Warren]

If it's deep enough, and/or covers enough of the root area, you'll essentially suffocate the tree. There also could be other problems with bare soil stacked against the trunk.

Just as the article you linked to earlier noted that stem girdling roots can be more of a problem with certain types of trees, those other factors will affect different types of trees to a different extent as well.

It's usually possible to create some kind of raised bed near a tree. How much area it covers, and how deep it can be depends on a lot of variables. What you seem to be describing sounds to be more than nearly any tree could tolerate. If you need to change the grade that much, you might as well count on loosing the tree.

You may want to consult with an arborist not just to confirm what's being said here, but to possibly offer alternative suggestions for whatever it is that you're ultimately trying to accomplish.

[dh321]

You may be able to raise the grade and protect the tree with a tree well.

[Travis]

You will smother it. The roots need oxygen. If you don't believe me ask your county extension agent.

[Nehmo Sergheyev]

- Nehmo -

Oops, it's Stem Girdling Roots (SGR or SGRs). You see, hard to believe, but even *I* make errors.

[Newt]

Hi Nehmo,

Maybe these sites will help to make it clear. Misperceptions about trees:

tree roots grow: collar and winding roots: flare problems that lead to death of tree from covering the bas of the tree:

-- Newt

[Stephen Henning]

Don't worry about Stem Girdling, worry about suffocation. Roots need to be near air. That is why they grow along the surface rather than straight down. Raising the soil level will suffocate the roots. Also, bark on roots is designed to tolerate being under the soil. The bark on the trunk is not and will either adapt or rot. Usually it rots.

Most people also forget that roots require oxygen. Raising the soil level will suffocate roots. Often the effects of construction damage are not immediately apparent. At one place the live oaks did not die from a

2-foot grade change until 10 years later.

If you built a retaining wall about 4 or 5 feet away from the trunk so the fill didn't come up to the trunk, the trunk would be OK. Since the tree is young, it might adapt to having the roots covered, especially if you prune the top of the tree considerably to compensate for the effective loss of roots. You many also have to install drainage tile if the tree well would likely fill with water. This might not save the tree, but it would give it a fighting chance.

[Treedweller]

I disagree with the suggestion to prune the top severely. Leaves make energy, and you tree will need energy to recover from the stress of root loss. Pruning out live tissue will reduce this energy production while requiring energy expenditures to recover from the pruning. Build the well and then, if branches die back over time, prune them out later..

Keith Babberney ISA Certified Arborist

[Stephen Henning]

But leaves also use water. As roots die, the top usually dies back to what the roots can support. So it really doesn't matter if you prune the top, it just is a choice of pruning out live material or dead material. But if you wait to prune out dead material, more of the tree will die because energy will have been wasted on branches that eventually died. The energy that is produced by the leaves is stored in the roots. If the roots are dying, then they won't store as much energy.

I girdled 3 walnut trees that were killing my rhododendrons. I was shocked that there was enough energy stored in the roots to keep the trees alive for 3 years. Then they died the next spring. So,in that case, I needed more top to kill the roots. The top I had took 3 years and I hadn't pruned these trees at all.

[Newt]

I agree with Stephen. If you reduce the amount of roots that ar feeding the top growth, then you will have more idieback. For example when root pruning houseplants to keep in the same sized pot, the top o the plant is pruned to accomodate the diminished roots.

New

-- Newt

[Treedweller]

I can't say I've done the experiments, but I've been to classes and read industry publications stating that you should not prune the top of a transplant until the bottom has a chance to get established. Myabe houseplants are different than trees, maybe you've both fallen victim to an old myth, or maybe the current industry-produced research is wrong. I leave it to you to decide, but I won't prune the tops of trees to compensate for root loss.

Keith Babberney ISA Certified Arborist ISA Certified Tree Worker/Climber Specialist

[Cereus-validus.....]

Mmmm! Stem griddled roots!

Doesn't that sound like something good to eat for breakfast?

Fry them up with onions and tatters and serve with butter and Romano cheese!!!

Yum, yum!!!!