While I can understand the desire to have a nice lawn that goes all around the trees, it also seems extremely important to always be considering the health and welfare of any existing trees.
If I had -- in my yard -- the exact situation you have (and, believe me, I've created for myself similar sticky situations
) I would:
1. Apply the sick tree treatment (
http://www.dirtdoctor.com/organic/garde ... n/id/2205/)
2. Give the whole drip zone (any ground area within the circle of the leaves and canopy of the tree) a 1-3" thick layer of shredded leaves, partially completely compost, pine straw, or bagged organic compost, to give the trees some TLC on their root zones. If you do this, take care NOT to pile mulch on the root flare. Here's more on properly exposed root flares (
http://www.dirtdoctor.com/organic/garde ... n/id/1609/) and improperly exposed root flares (
http://www.dirtdoctor.com/organic/garde ... n/id/3590/).
And I would not -- again, for my yard -- grow grass around the trees at all. In a few minutes, I'll post a pic of our 50' oak tree which was in
severe stress when we bought our house. After a lot of work, including implementing #1 and #2 above, and maintaining the mulch (which currently needs to be weeded...
) our tree has ceased losing branches and even has some new growth on branches that we thought were dead.
Hope that helps, and I hope you can save your trees!
_________________
God speed!
Cara
**
Take time to stop and smell the flowers!
(or... as my ladybug refrigerator magnet says
"take time to stop and
eat the flowers!"
)