Hello Benny,
Thank you for your explanations, I really appreciate it. the only yuccas that are planted high are some of the elata X filamentosa hybrids and it's because they were already like that in their original pots but let me explain why: while growing them indoors over the winter I had a spider mite infestation, those tiny pests were feeding from the leaves of my seedlings, while trying to control the infestation some yuccas had their leaves damaged so I peeled off those leaves completely & instead of having new leaves come out at the base, it came out a notch higher and as I was peeling away other infested leaves new leaves were coming out a bit higher just like a ladder effect, when I finally managed to control the infestation it left many yuccas with a small or tall green stem that slowly turned hard & brown. so when it came time to put them outdoors instead of burying the stem I decided to plant it at the height they were in their respective pots, also those with stems don't have any offshoots (yet).....I think I will be extremely careful to protect those for this coming winter, frost cloth/mulch?