Hardy to 20F. Better pot the up and take them in. Will not live here I do not believe.

I agree with beerhog. Even with a pretty warm winter last year, we still had some nights much colder than what your agave could tolerate. Even if your plant was cold-tolerant down to 0-10 degrees, it would not survive in the ground like cannas do. Cannas are a lot more tolerant of cold, wet soil than most succulents are. I am about as far south in OK as you can go and still be in Oklahoma, and I'd never attempt to keep your agave variety alive in the ground here over the course of the winter, and that is partly because we generally dip down into the single digits a handful of times each winter but also because most of the soil on our property is slow-draining clay that stays wet much of the winter (or, at least it holds water a long time when it actually is raining).

I have tried to push the zone limits here and grow some beloved Zone 8/borderline zone 7b plants that I could grow in Texas just 80 miles south of where I now live and I have lost every one of them to cold weather. I might not lose them in their first winter here, if that winter was very warm and very dry compared to typical winters here, but I did lose them in an average winter within 2 to 4 years of planting them here and I am in zone 7b.

Dawn

Thanks so much for the info!!! Sounds like I got some digging and potting to do today!
Which zone 8 plants did you try? We just moved into our house that actually has 3 large flowerbeds and two smaller ones. So techniqually this is my first year having an actual garden. I tried a few years back but between the gophers eating ALL of my bulbs, including Asian lilies, and the fact we decided not to stay at that place for the long haul it wasn't practical. So all of my plants have been in containers. I was able to over winter most of my plants on a covered south back porch wrapped with many bags of mulch.

Maybe it's just wishful thinking but I will disagree with answers... I have recently planted the entire array of Manfreda xs in Cherokee (NW OK near KS) and expect them to defoliate but overwinter just fine. They are however in well drained sandy soil with gravel mulch and will receive no supplemental watering. They are with Agave parryi and other cactus species native to the western plains. I'll update on the fate of this garden next spring!

Ladymedusa, Just pick any beautiful zone 8 ornamental plant, and I have planted it here and lost it in a wet, cold winter. After about a decade of that, I quit trying to push the zone limits. Banana shrub (Michelia figo, I think) lasted the longest at 4-5 years, but Texas Mountain Laurel died in its second or third winter, as did the jasmine.

One problem with dense clay soil is that the plants that might tolerate it in dry, hot weather will die in it in prolonged cold, wet weather. Native prairie plants that are adapted to clay in both of those types of weather/soil moisture conditions do better for me than fussier ornamentals that need humusy, well-drained soil.

Chriser, The kind of soil is key. You sometimes can get away with planting stuff in a colder zone if you have very well-drained soil (which I obviously do not) or a warm, sheltered microclimate that meets their needs. I hope your plants do well there for you in Cherokee.

Dawn