@Pinusresinosa - I agree, looks like Color Guard, and good info you have on your site! I possibly planted my yucca too deep.
Wish I was closer to your nursery.
If I remember right it took quite a few years for mine to flower for the first time, Nyboy. Once they flower, however, they seem to flower every year. Don't give up on 'em! One flower spike will make all those years of waiting fade away.