Preparing concrete wall planter
Hi, I would like some advice on how to prepare a planter.
The planter is built against the property wall.
The property wall is concrete blocks.
The planter is poured concrete.
The planter is 3' wide.
The planter starts about 4' deep, and ends about 2' deep.
The surrounding patio is poured concrete.
The bottom of the planter is partially covered by the wall footing, the rest is open to the ground below.
I will be planting tall trees / shrubs for privacy from the neighbor on the tall end of the planter.
I would like advice on how to prepare the inside of the planter.
Do I need to lay down a barrier to keep roots from going deeper than the bottom of the planter?
Do I need to install drainage at the bottom of the planter, or just an overflow drain?
What materials in what layers do I use to fill the planter?