Zero palms will survive there unprotected in zone 5,no matter what anyone tells you-
they will always need to be covered and heated during the coldest winter temps.

Ontario doesn't get extremely hot and humid ever, but regardless your windmill did not die because of temperatures in August. Perhaps that is when it took it's last gasp after winter damage. Or maybe it was not healthy for other reasons. I wonder about your theory of minors growing as perennial. I have heard of some zone 7 or 8 folks growing Washingtonias as perennials so hey it might work. As slow growing as minors are though you'd probably barely notice them when they started shooting out of the ground.

I lost a trachy once in August. I still have no idea why, it was well watered, but probably was unhealthy before I bought it and it rotted. It was definitely not because of heat, Trachys actually handle heat pretty well especially when watered. I've seen them growing in Florida (they dont look good in the sun though!) and its in the 90s daily there for months.
There arent any palms that will survive a zone 5 without protection, but adding a little bit of protection isnt too hard, depending on how warm you have to keep your palms. Trachys are reliably hardy to 10F, mine have seen colder without protection and survived (with some damage). They get more hardy as they get older and can probably handle brief dips to near 0F with little damage when mature (but not longterm or repeated temperatures like that).
Needle palms can handle 0F when mature without damage making it the most cold hardy palm there is. Sabal Minors are another cold hardy option (its cold tolerance varies from around 0F to 5F), but I personally think Trachycarpus is the best one to start with!
Good luck!
-Alex

None. In a 5a/5b climate you would need serious protection for the palms all winter long. You can do that if you prefer, but no palms, cycads or cordylines will grow unprotected or with just burlap. You will need to use an external heat source to provide additional protection as well as straw and burlap.

I wish you the best of luck. My best advice is to grow them in pots you sink into the ground during the summer. Use hardy bananas you can lift and store in the winter too. That will produce a nice tropical effect. Add in some ginger, cannas and hibiscus and it will look great.

I would also like to point out that while a Trachycarpus can survive a brief dip to around 10*F and a needle palm to around 0*F, the key word is brief. I've grown sabal palmetto, needle palm and windmill palm, and from my experience, if your soil freezes in the winter and stays frozen for longer than a couple of days, your palm will die. I've heard many people say that the needle palm is hardy to below zero so therefore it will grow in my area. It won't without serious protection. In its native habitat the ground doesn't freeze 6-12 inches down, nor is it subjected to temperatures below zero on a regular basis, two things that happen with regularity in a zone 6. Needle palm and sabal palmetto are reliably hardy to zone 7, windmill palm (trachycarpus fortunei) to zone 8.

where do you live in zone 6 cliff? IDK if I would say freezeing 12 inchs and below zero is a common thing for zone 6 anymore give it about 5 more years adam and you can grow a palm with no protection, global warming is awesome LOL

Don't let back to back warm winters fool you. 2010/11 was brutal and only 2 years ago. I think that we earned a couple of good ones with those bad ones 2 and 3 years ago. It all balances out.

I have to agree that at least my zone 6b, the ground definitely doesn't freeze down 12 inches, maybe 6 during really cold weather, but in order for the ground to freeze that deep, there wouldn't be snow cover, which is an insulator.

I also agree that trachycarpus (especially hardier cultivars) and possibly needle palms are your best bet and worth growing even if you have to protect them. Even if a needle palm survived unprotected, it would not come out healthy or looking good. Even a burlap wrapping would help against sun and wind dessication.

I have to disagree that ontario never gets hot and humid. Do a weather search of Amherstberg, ON. The southernmost location in Canada. Right across the river from me. If the midwest can get hot, then so can Amherstberg. That being said, a zone 5 Ontario must be quite a bit further north than Amherstberg, so can't speak for their weather. But Minnesota has been known to get hot.

I'm in Cincinnati, Ohio. Looking at 50 year averages, most of the area is a zone 6. There are a few micro-climates along the river and near downtown that are zone 6b using the same 50 year average. I have experienced first hand the ground freezing deeper than 12 inches in a winter where the absolute low was only a zone 6. Several nights at or below zero with highs in the teens will cause any moisture in the top 12 inches of soil at least to freeze. Yes, those winters don't occur every winter, but we do drop to at least 0*F almost every year. Last year was a freak year. I think our absolute low was 17*F. I tend to go by 50 year averages.

The absolute lows must be the deciding factor, in addition to lack of snow cover. If you guys are getting down to at least zero or colder most winters, then that is a true 6a.

I moved to my current house from Cincinnati I lived there most of my life and I know how bad the winters can be but I just don't see it being that way anymore or for a long time from now. this side of the river got down to 12 one night for a few hours last year but nothin to freeze the ground a foot deep

Considering I'm Zone 5b, I'll answer some questions. Will a Needle or Dwarf Palmeto's live unprotected in our winters? Probably not, the moisture will kill them with the big freezes. Coconut Mike does have unprotected seedlings growing beside his house, usually covered with snow and he is closer to a 5a.

If your windmill died in August, it had nothing to do with cold but on how you planted it, cared for it, watered it, fertilized it, pissed on it. I have a 10 ft windmill in ground with protection. Check my other posts for images.

I also have a Pindo palm with protection and heat and a Wagy with protection and heat.

I have a dwarf palmetto with a rose cone and a needle with only a blanket and tarp up until Sunday where I also threw a garbage can over it. -20 at night has been our low this year.

I'll have pictures of my two non heated palms posted in a new thread shortly which I took last Saturday.

protect a needle every year eventually it will be a big palm bush but even that is a remote chance