Pin Oaks killing grass (growing plants, butterfly, trees, front yard)

[Dirt Grinder]

We have three fifteen-year-old pin oaks that have started raising their roots above ground and have killed the grass under the trees. The roots have risen 6 - 8 inches above ground. Anyway, our homeowners association has written us up and demand we rectify the situation. I have added "topsoil" to cover the roots but pessimists have said the roots will just rise above this.

So - what's the best way to correct this situation? Do I add topsoil to cover the roots and add a groundcover under the trees or do I add sod on top of the topsoil? I have raised the canopy on each tree to a good twelve feet so sun will reach under the trees now.

Thanks for all responses.

[J&Em]

Your HOA is asking you to kill your tree? Shallow roots are common with pin oaks, they tend not to have a tap root or deep root system. Instead they have more shallow roots in order to pick up oxygen and nutrients in the top few inches of the soil. In compacted and poor soil this happens more commonly and the roots actually break the surface as the tree tries to survive. Adding more soil on top, at least anything more than an 2 or 3 inches will result in it being smothered (oxygen deprivation) and sending new roots towards the surface. That may be what the "pessimists" were telling you. If you add enough soil to smother it the tree will take a while to die but it will slowly die.

You indicate having trimmed the lower branches to get more sunlight which will help with grass growth. If you spread a fine layer of topsoil and add grass seed that thrives in shade conditions you may be able to keep enough green to keep the HOA happy. If they give you further grief you may want to contact an arborist in your area that can explain to them that they will cause a thriving tree to slowly die.

If the still HOA insists on coverage you may be able to lightly mulch the area to make it look "neater" rather than add soil. Make a neat edge to make it look manicured enough but a light mulch, renewed periodically, will not suffocate the roots as easily.

As a last resort if all they want is something green beneath the tree you can add a thin layer of topsoil (no more than 3 inches!!) and plant low growing plants like liriope or vinca minor (the perennial vine plant). They can spread among the roots and cover them. They will hide it far better than grass once they have filled in.

Here are some links to read up on the issues and maybe give you some ammunition in showing why what they want is a bad idea if they won't let you do anything but cover the roots and plant grass.

Trees: Damage

Tree Root Problems

[Bulldogdad]

I would just leave the area clear of grass and plants, better for the trees.

You can add soil so the roots are flush at grade.

What exactly does the HOA have a problem with, the dead grass or the roots rising above grade.

[Dirt Grinder]

Originally Posted by Bulldogdad

...What exactly does the HOA have a problem with, the dead grass or the roots rising above grade.

"Any exposed tree roots are to be covered."

[Cambium]

You planted a tree on land you dont own? If there's an HOA that means that might be common ground (not all cases the same).

So I should ask... Is that common ground or your property?
If its your property, tell them to go ____
If its common ground then did they give you permission to plant them?

If no, then you need to rectify this.
If yes, then maybe everyone can settle on something.

Adding top soil is covering the problem that will resurface.

I personally think the only way is to, either use the trees as firewood, OR dig down with a machine half foot which means cutting those surfaced roots and leveling the area underneath the trees. Chances are the trees will be fine and its a win win for everyone. If they arent fine in the future, then they werent the right trees to put there in the first place.

I have 2 growing in my front yard. So I understand the willingness to keep them.

[Butterfly4u]

Dirt Grinder,
Mulch.

[Dirt Grinder]

Originally Posted by Butterfly4u

...Mulch.

Yeah, we thought about that but I hate to create three twelve-foot mulch islands in the yard.

[Dirt Grinder]

Originally Posted by Cambium

You planted a tree on land you dont own?...

Three trees on my property.