We are looking at putting in pool and screen of evergreens along our back fence for noise abatement.

We are considering options like Italian or Leyland cypresses. Something dense and with a trimmed/neat look to them. We live in Memphis, TN. For extra noise control and some visual interest (yard is dead flat) we want to place the trees in a raised planter, masonry 2-3' high with stacked stone facing. Since these will be a noise screen the trees will be planted fairly close together. Our soil is heavy sticky clay, but we will be able to condition what is going in the planter somewhat. Ideally the trees will grow to about 12-15', probably buy 6'.

2 question:

-Other tree suggestions?

-required width of the planters to allow the roots to spread and not be suseptable to wind. Assume planter foundation will only be around edges so roots could grow down.

Thanks