Soil over base of Oak Trees

[Homer A. Purdy]

My son in law recently purchased a home in Orange County, NY, where the bases of a number of mature (1-2 foot diameter) Oak trees were covered with soil from the basement excavation. Supposedly covering the base of the trunk isn't good for the tree.

The "foot", where the trunk reaches out, is covered in almost every case. From what point do you measure, and how much soil is acceptable?

If he digs away the soil and builds a retaining wall, how high, and how far away should it be from the trunks?

Any other recommendations?

[John Paul Sanborn]

It would be best to get an arborist who has experiance in remidiation of construction damage to do the work or at least draw up a plan.

The root flair should be above ground and the first roots should be at grade. A 12 inch tree may grow roots in the new soil that will eventualy girdle the trunk. Not to mention the increased suseptability to root rots plant in this situation have.

USing compressed air is the best wasy I have found for excivating in the root system. There is a new tool ou there that soem arborists have called an Air Spade that is wounderful.

After getting the exess soil away, then he needs to relieve the soil compaction in the root zone caused by heavy machinery rolling around. The Air Spade can do this too, trenching radialy and then augmenting the soil with organig mater.

Lastly, mulching and colonizing the soil with a native worm (nightcrawlers are not native to may northern areas. In tourist fishing areas the introduced worms are changing the forrest floor by being too agressive in consuming the leaf litter.)

[Eric E.]

The actual covering of the root collar isn't the worst part. More of a concern would be the covering of the root system. Along with the covering of the root system is the concern of the compaction from the equipment that was used in the covering operation.

At this point retaining walls probably won't help much.

Where in Orange county? I'm across the river in PA. If your son is intrested I am available for on site consultations.