I'm pretty sure you can. I see lots of yuccas that look like they've been topped off to encourage branching.

I agree. I think yuccas are pretty much indestructible.

I had one growing that I wanted to get rid of. I hacked and hacked at the trunk, dug a moat around the base and kept it filled with water hoping to rot it out. It finally rotted and I set the rotted stump aside, filled in the hole and about a month later a baby yucca was growing out of the hole. 2 months later I noticed to yucca babies growing out of the rotted piece of stump that was just sitting there. It's been 2 years now and babies are still growing out of both the original hole and the stump. One tough plant!

wanda

Now that you know you are not going to kill it, back to the question of what will it look like cut off? The pups growing on the base of the old stem will grow and fill out and in a year or two and cover the stub. If it were mine I think I would consider removing the pups from the stem and planting them in pots to grow on. After 6 or 7 years the soil in the old pot must be in such a poor condition only a yucca could survive in it. I would discard the old plant and the soil and start over with new soil formulated for long life. If you want the best architectural looking plant just plant one of the old pups in the rejuvenated container. I prefer the look of a healthy new plant over an old revived one. Al