So to make a retaining wall that will last as long as life you should consider going with concrete blocks.
How to build a poured concrete wall.
Create contraction joints every 4 6 feet.
Pour footings and wall.
Allow concrete to cure.
See below for more information on contraction joints remove forms and install waterproofing and drainage system.
Measure and mark footing locations.
Measure out from that nail to where the other face of your wall will be and place another nail.
Once the first row is installed pack native soil to grade level on both sides of this course to anchor the wall in place.
Try to make the frame pieces as long as you need them to be.
Finish the surface of the wall as desired.
Drive a nail into the concrete here.
Measure from the edge of your concrete footing to the point where the outside face of your wall will be.
The retaining wall can be made from concrete blocks poured concrete treated time boulders and rocks.
So if your wall is 8 inches wide your two nails should be 8 inches apart.
Then use the marking paint and measuring tape to lay.
Level to level blocks lengthwise and a torpedo level to level the front to back.
If you re building your own forms you will probably.
Install the first course of blocks using a taut string line to establish a straight row.
How to pour a concrete retaining wall.
Rest the frame pieces against a solid surface to prevent them from falling.
If you re building a long wall build the frame in sections.
If the wall exceeds four feet in height footings should be poured separately.