I have a stand of Gambel Oaks in my yard, I would like to leave the oaks, but fill in about 12 inches deep to level the area out. Will this damage the oaks? Is there any recommended ground cover to place in the area?



I do not recommend at all putting 12 inches of soil around the trees - any change in soil grade will essentially put the tree root collar a foot below soil and the bark will not do well.  Many trees which have the soil grade raised around the trees eventually succumb to bark rot or other problems due to burying the tree - also the roots are also covered and water and oxygen is less available.

As for ground cover - it's heavy shade under gambel oaks so realize you need something that can tolerate shade.  Generally I don't recommend ground cover close to trees - because of competition for water, nutrients, oxygen between plants and trees.  Best management practices for trees is to lay a shallow (2") layer of organic mulch like bark nuggets around the tree out to the dripline/canopy of the trees for the trees to be healthy and happy.

Posted on 27 Mar 2009

Maggie Shao
Horticulture Agent, Salt Lake County

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