There are all different types of Yucca. Some will live here, some will not. It sounds as if yours is more the houseplant variety.

In which case, would be fine to place outdoors during warm weather, in a pot. But I wouldn't recommend planting in the ground.

If you are sure of your own zone and sure of correct identification of your plant, then it does look as if you may have to repot and bring your plant back inside. Those zone numbers are not perfect but they're a pretty good indication of what will grow well for you in your area. You could grow plants rated for zone 7 or lower, but you are risking your plant if rated higher than Zone 7.

There are many Yuccas rated for your zone (and colder zones), one of which undoubtedly was what your Grandmother grew.

I'd repot your plant, water it very lightly for the next few weeks until I saw new leaves appearing which would indicate recovery from the cold. Then you could move outside for the summer...but definitely plan on taking it back inside next fall. Good luck...hope it wasn't permanently harmed. Yuccas are pretty tough so might just lose a few leaves. josh

Here is a link that might be useful: Yucca elephantipe

Thanks for the input. I was afraid of that. They are the palm tree looking yuccas, just to clarify. They do have some new sprouts on the trunk, so I think they might make it. I should have mentioned that not all of the leaves were damaged, just a few of them on each plant. I planted four of them in the ground yesterday, but it looks like I will be uprooting. Thanks for the help.