Mine has tolerated down to 20F but it is in a pot. I think the larger they get the better they handle the cold. They are able to handle the cold better when growing in the ground. Try taking off the bottom of a milk jug and put over the plant, the pouring hole will allow for air which they must have. Fresh air keeps them from moulding. I need to practice what I preach I lost two plants this year to the rain. (Lesson) So I keep must keep water out of the tops. Norma

i honestly wouldn't push that aloe in zone 6. Maybe you could try aloe polyphylla or aloe striatula. Those are both pretty root hardy but i would still protect them the way you do with your agaves but maybe some mulch around the outside of the container about halfway up. What agaves do you grow? the only ones i overwinter are A. parryi var. truncata. i also have several cacti.

I quit trying aloe's, this is my first year with agave parryi. I have truncata, flagstaff and JC raulston. I hope these prove to be as hardy as my havardiana's. Those things are bullet proof. I just go out after a snow and sweep em clean with a broom. My agave gracilipes and ovatifolia does great but I do protect them.

Banana,
Thanks for the advice.... if I can get one I think I'll pot it and bring in into the garage until it makes little ones and then I may try a little one and keep momma for ensurance. That's how I do my basjoo banana.

As for my hardy bed, I do Agave Havadrdiana, parryi (salman, flagstaff, and one just labeled as plain parryi), and utahhensis. I'm on four years now with temps below zero, ice storms, up to three feet of snow and really wet winters. Here, we can have a foot of snow one day, then be in the 60s with rain all day the next. As the big agave parryi has been putting out babies, I do not protect them, but I do protect all the others with my clear plastic containers.
I also have lots of different kinds of Opuntia as well as some different echinocereus and corypanthas, and I've only lost one! I'm very happy with the results, especially when I read about so many people losing agaves, and things going to mush.

I even started a hardy bed at my middle school with my special needs students, and am now wanting to start one at my new elem. school. Echinocactus inermis is really good with kids.... plays nice ;)
Later,
Chris

Sounds like you have an awesome garden! i am thinking about making a new bed this year. Your climate sounds just like mine! very unpredictable lol. For cacti i have several opuntias christmas cholla (which i guess you can consider opuntia too), and lots of non-hardy ones that i plant for summer. I was at a local nursery one week, they had both corypantha vivipara and sulcata and the next week they were sold out :( i also tried to buy hardy echinocereus off of ebay but everyone keeps outbidding me hah. o well. oh and my other agaves are lopantha quadricolor (i might try to overwinter a pup), victoriana, and potatorum. post some pictures of your bed and i might at the end of the season too!

My A. arista lived through 1 day of 11 degrees under a pot and dried grass, year before last, but bit the dust with three nights of 12, 14, and 16 degrees, then three more in the 20'sqne. Then we had no freeze. It's roots rotted and leaves turned to jello. I am not buying another for outdoors. An extended freeze did not suit it. true, I did not cover it as well this year/. I only used a pot and no grass.

Thanks for all the input gang!

Banana, Some of my plants came from high country gardens, but the best plants I've seen came from Kelly Grummons at coldhardycactus.com. He sent amazing plants when I ordered some for my school bed. some of the echino's had two barrels in each pot, and the inermis,which is awesome looking, had six babies around the base.

My first agaves came from High Country. One of them came loose and was beat up in shipping, but they told me to plant it even though it looked bad and they would ship another to replace it... both are alive and well, even though it took a good year and half for the beat up one to recover.

I probably have close to 25 different kinds of colorful opuntias. My favorite is Mesa Melon... it looks like it glows when in blossom.

My problem is that when I started into hardy ones, I didn't think I'd have many survivers, so I planted things rather close..... I have to expand my bed or build another, because I've only had one casualty, and I think that's because I had a bruised barrel on one of my echinos.

Yesterday I filled an old fashioned wheel barrow full of Opuntia engelmanii and O. albispinus. They grow huge with pads usually around a foot long.

I will post some pics this summer.