My sibes are planted in unamended heavy clay. I water them during dry spells during the first summer and then never again. You may be over thinking this.

They need no special soil prep or care. Just dig a hole and plunk them in :-) Water as necessary the first growing season and then only in extended dry periods thereafter.

Thanks for the response's. I have some that will be here this week and just wanted to know how to help them survive.