landscaping wall

I'm making a little wall (19" from top to bottom of the blocks) under a roof that is attached to the side of my garage. The wall will be less than a foot from the foundation of the garage. The point is to level out the area under the attached roof, which slopes away from the garage. The soil here is very sandy and well-drained. Most of the info I've seen recommends putting down a layer of compacted crushed stone for a foundation. Seeing as 1) the location is so well-drained; 2) the wall will hold back only a small amount of earth between it and the garage; and 3) the sandy earth provides a pretty stable substrate--Do I need the crushed stone, or can I lay my blocks right on the sand? If not, what would be the reason? Thank you...

 

This started as a question using a board?

Sand is soft, not a solid foundation, can you use it but eventually it will give and the wall, even a small one will start to sink.

If you want to redo in a few years sand will work but advice is to use the correct material form the beginning and not have to worry about having to repair.