Using guava timber for a garden barrier?

[Atlantis420]

Aloha,
Recently, I cut down a TON of waiwi. If I re-purpose the timber for garden beds will it root in place?
If it roots should I wait until it is dead from sitting in the pile?

Side-note:
Is the strawberry guava pronounces like waiwi or gua-vi? I have heard both and the people who pronounce like gua-vi look at me like im nuts pronouncing it as waiwi (vi-vee).

Thanks!