exposed roots

[wjjmlg]

what is the best way to cover roots in a yard when they are sticking out of the ground two or three inches up. i have a customer that is sick of mowing her grass and then has to weed eat the grass around the exposed roots. i'm sure if she adds three inches of dirt every where it will probably kill the tree. is it ok to add a little dirt every couple of weeks until roots are covered, or is it just a no win situation. by the way it is a live oak tree about 25 -30 years old. any info. will help. thanks.

 

[Daddy M Dawg]

Mulch

Add mulch to the area to cover them.

 

[pdqdl]

... is it ok to add a little dirt every couple of weeks until roots are covered, or is it just a no win situation. by the way it is a live oak tree about 25 -30 years old. any info. will help. thanks.

Yes. That will be a nearly perfect plan. Use dry pulverized topsoil and sift it into the grass and exposed roots about an inch at a time. Wait a couple of months, do it again.

An alternative method if you are visiting that location often is to just add a few bags of topsoil every week. Done in slow enough increments, the lawn will raise and the roots will go away, and you will never even notice the dirt as it is added.

You should be aware that there is a large contingent of arborists that believe that there should only be mulch underneath a tree, all the way out to the dripline. I understand that is not practical for most areas, and quite unacceptable to most customers.

I would recommend adding enough soil around the base of the tree to keep the root flare at least partly embedded in topsoil, then add 3" mulch in a circle forming a neat landscape bed about 6-10' diameter, depending on the size of the tree. Consider planting some understory shrubs or flowers in the mulch area.

Add topsoil in gradual increments until all the roots are covered, and the lawn should fill in very nicely. Easy mowing, nice lawn, with no mower damage to exposed roots. Depending on the severity of the problem, 1-2 years will be plenty of time to allow for the tree to grow into the new soil without suffocating.

[I expect a hailstorm of protests from the "tree-first" crowd, but not everyone has that point of view.]

 

[wjjmlg]

thanks for the info. i will talk to the homeowner next week. it will be a long process, but she just bought the house so she will have all the time to watch the roots disappear one month at a time. thanks for the help.

 

[M.Green - SVTS]

what is the best way to cover roots in a yard when they are sticking out of the ground two or three inches up. i have a customer that is sick of mowing her grass and then has to weed eat the grass around the exposed roots. i'm sure if she adds three inches of dirt every where it will probably kill the tree. is it ok to add a little dirt every couple of weeks until roots are covered, or is it just a no win situation. by the way it is a live oak tree about 25 -30 years old. any info. will help. thanks.

Can I ask why adding dirt on top of exposed roots would kill the tree?

 

[gitrdun_climbr]

Because absorbing roots live at a depth where water, oxygen, gas exchange, nutrients, etc. are optimal. As little as 3 inches of soil can cause an overnight oxygen deprivation severe enough to start killing roots off.

Kind of like how a piece of plywood on your lawn kills the grass real fast.

I've extracted these protruding buttress roots before with no visible ill affects to the tree. Not advised on tall trees with valuable targets around and there are many other factors to consider when taking this approach. Homeowner should be documented as understanding and accepting the risks.

 

[BC WetCoast]

Yes. That will be a nearly perfect plan. Use dry pulverized topsoil and sift it into the grass and exposed roots about an inch at a time. Wait a couple of months, do it again.

An alternative method if you are visiting that location often is to just add a few bags of topsoil every week. Done in slow enough increments, the lawn will raise and the roots will go away, and you will never even notice the dirt as it is added.

You should be aware that there is a large contingent of arborists that believe that there should only be mulch underneath a tree, all the way out to the dripline. I understand that is not practical for most areas, and quite unacceptable to most customers.

I would recommend adding enough soil around the base of the tree to keep the root flare at least partly embedded in topsoil, then add 3" mulch in a circle forming a neat landscape bed about 6-10' diameter, depending on the size of the tree. Consider planting some understory shrubs or flowers in the mulch area.

Add topsoil in gradual increments until all the roots are covered, and the lawn should fill in very nicely. Easy mowing, nice lawn, with no mower damage to exposed roots. Depending on the severity of the problem, 1-2 years will be plenty of time to allow for the tree to grow into the new soil without suffocating.

[I expect a hailstorm of protests from the "tree-first" crowd, but not everyone has that point of view.]

Sand is another viable option for a top dressing especially in areas with a heavy clay soil. Most golf courses use sand as a top dressing after they punch the fairways and greens.

 

[Sunrise Guy]

Covering the root flare, at least closer than 3-4 feet from the base of the trunk, is strongly ill-advised. The majority of gaseous interchange, at ground level, takes place via the root flare and if it's covered, the tree starts to suffocate. You can try to grade the area that is further out from the tree if roots are exposed there, but do not add soil within that 3-4 foot zone, as above. If the tree is very large, as in a 4-5' DBH specimen, that zone should be 4-5' or more, depending on the tree. Covering the area within the CRZ with only mulch is impractical, for the most part, particularly if the tree is very large and a given yard small, but I have seen, over and over again, how "luxurious lawns" that are allowed to grow right up to the base of the tree have triggered a descent into a downward mortality spiral for the tree that only scalping back the lawn can turn around. A swale and berm of good organic mulch is the way to go, after the root flare is exposed, with a radius, as above.

 

[BC WetCoast]

Covering the area within the CRZ with only mulch is impractical, for the most part, particularly if the tree is very large and a given yard small, but I have seen, over and over again, how "luxurious lawns" that are allowed to grow right up to the base of the tree have triggered a descent into a downward mortality spiral for the tree that only scalping back the lawn can turn around. A swale and berm of good organic mulch is the way to go, after the root flare is exposed, with a radius, as above.

I think it really depends on the species as I have seen many trees, with the lawns growing right up to the base, doing spectacularly.

 

[Rookie1]

How about a crimson maple? Wifes aunt/nextdoor neighbor has one and I tried to fill in roots. Shes 85 and I cu her grass and its a royal pian to cut around theose roots. She must know bout the roots being exposed cause she said it would kill the tree.

 

[pdqdl]

Same story as above. All those roots were once underground, the problem is not covering them, it is covering them too fast.

Give it a few years, everything will be fine. Add the topsoil slowly, the tree will benefit from a few inches of restored topsoil. Obviously, dirt piled deeper than the root crown would be bad, even if you took your time.

Most exposed roots are the result of many years of slow erosion, mostly the result of ground cover to protect the very surface of the soil. The buttress roots, however, continue to grow in diameter, and consequently erupt out of the soil.

If the buttress roots were in a woodland setting, there would typically be many years of deposited organic material that would continue to cover those roots. In our quest for better looking yards, we clean up the leaves, remove the soil covering, and we get exposed roots.

 

[Toddppm]

Most exposed roots are the result of many years of slow erosion, mostly the result of ground cover to protect the very surface of the soil. The buttress roots, however, continue to grow in diameter, and consequently erupt out of the soil.
.

I'm kind of doubting erosion is a main culprit unless it's on a hillside. Are you saying groundcover contributes to erosion?
There are areas around here where you are certain to see exposed roots in most of the neighborhood, I've always figured it was the soil itself didn't have enough or the right types of nutrients and there wasn't enough oxygen/water and too much compaction so they grew on clsoe to the surface?

Yes I think you can slowly add dirt but the roots will continue to grow close to the surface and get exposed again because you can't improve the soil they're already in.

 

[Labman]

About 30 years ago, I hacked off the exposed roots of an osage orange tree in my back yard. it may be declining now.

More recently, I mulched around the exposed roots of a meta sequoia at my church. Many complements and the tree is doing fine. Your think pleasing a home owner is tough? At one time another guy and I were almost lynched for cutting off some lower limbs from it.

 

[BC WetCoast]

I'm kind of doubting erosion is a main culprit unless it's on a hillside. Are you saying groundcover contributes to erosion?
There are areas around here where you are certain to see exposed roots in most of the neighborhood, I've always figured it was the soil itself didn't have enough or the right types of nutrients and there wasn't enough oxygen/water and too much compaction so they grew on clsoe to the surface?

Yes I think you can slowly add dirt but the roots will continue to grow close to the surface and get exposed again because you can't improve the soil they're already in.

It also has a lot to do with species. Cherries always have surface roots. Spruce usually have surface roots, but in nature they tend to grow in wetter soils, so the roots need to be near the surface to allow air exchange in saturated soils.

I don't think it is soil erosion that is cause the roots to surface, rather the young root is growing just below the surface, fully covered. As it ages, it expands in diameter and the rises out of the ground. In other words, the diameter grows faster than the ground surface changes.

 

[pdqdl]

I'm kind of doubting erosion is a main culprit unless it's on a hillside. Are you saying groundcover contributes to erosion?
There are areas around here where you are certain to see exposed roots in most of the neighborhood, I've always figured it was the soil itself didn't have enough or the right types of nutrients and there wasn't enough oxygen/water and too much compaction so they grew on clsoe to the surface?
....

As explained above, three things are at work with exposed roots. BC Wetcoast did a nice job of explaining that different species and conditions cause increased surface roots. Add to these general trends the fact that roots increase in diameter as the tree grows. UNLESS the groundcover (be it natural accumulation of leaves, dust, detritus or turf) continues to add to the soil level as the roots mature, you will find erupted roots. Not just occasionally, but every time!

In contrast, look at any mature tree (growing in a turf area, not a woodland) that does NOT have exposed roots. You will usually see that it is growing on a naturally formed mound, where the soil level rises to meet the root crown. This is because the soil level rose with (and because of) the trees developing root system.

Generally, in a US residential area, the lawn is mowed and doing fine, until the recently planted tree matures. Competition between the lawn and the tree causes the turf to thin out and go away, leaving bare soil at the base of the tree. Since there is no other ground cover present, as there would be in a woodland setting, the soil level slowly erodes, or at best, does not increase to keep pace with the ever expanding roots.

Voila! After 30 years, you got exposed roots that you can't run a lawn mower over.

I must confess, I typed out my text too hastily earlier. I said "...mostly the result of ground cover to protect the very surface of the soil". I should have said "mostly the result of inadequate ground cover to protect the very surface of the soil".

I guess in summary to your doubting soil erosion as a cause: soil erosion takes two forms: 1. removal of existing soil, and 2. Failure to build new soil as the tree develops.