The 'fastest growing hardy palm' is probably Washingtonia Robusta, but it is not hardy anywhere in Ohio without good winter protection (wrapped, lights). It loses most of it's foliage at 20 deg.F and will die at 12-15 deg.F unprotected. I know of no place in your state where you can expect to get through an entire winter without going down to or below those temperatures. It can be done, but you have to do a lot of work to keep these babies alive where you live. There are hardier palms, but they are all relatively slow growers compared to W. Robusta. You might consider tall species of yucca which, if grown in sandy or loamy soils, will survive there. Good luck.

I Have washintonia robusta (Mexican Fan Palms)it's just a matter of being smart in your climate I just planted 300 seeds So In A couple years there be ready to go outside.
I have A lot of room for plants. My drive way is half a mile long and i'm soon to have around 100 acres all together. I also have (I'll just call them by there nick names)
2 Needle Palms
2 Pindo Palms
2 Chinese Palm(livingston)
Around 25 Chinese Fan Palm (trachycarpus)
So Yeah... I have those Hardy Palms.
But is there any faster growing hardy Palms?
Thanks, Joe

Unfortunately most of the cold tolerant palms are very slow growing because of there cold tolerance. I guess its just a matter of waiting. The less damage they get every winter the faster they will grow, and fertilizer helps too, just make sure to stop giving it fertilizers in mid august because then the growing should begin to slow down so there is less tender growth when winter comes.

Good luck!

Even if you clearly define what you mean by cold hardy that will not change the fact that no palm will grow there without protection,best chances,Needles and(select) Sabals(Louisiana,Birminghamn,McCurtain).
This does not address winter cold,you WILL have to do that with protection.Sabal or a Needle has the best shot without protection AFTER it becomes established.

To strictly address the term "fastest"(as mentioned)Washingtonia robusta with major protection.
The caveat is that it needs heat in summer to put out a high leaf total and once again that is after it is established,

The simplest answer is a Trachycarpus fortunei.
There have been cases of Trachys putting out 15-20 leaves in a season,which would put them in the same league as Washingtonia,without needing the extra heat.

What I meant by "being smart about your climate" is using winter protection and knowing how much you need I'm sorry I used bad word choice.

Joe - I live in 'burbs of Detroit. In our climate, you definitely want to go with Trachycarpus. They by far outperform anything else, probably do to the fact that they come from coolish summer temperate to subtropical regions, whereas the sables and needle palms are used to the hot, sticky summers of the American southeast, and, while they might survive for you, just won't thrive and put on the growth a Trachy will. This is especially important if you don't give the plants massive protection to overwinter a lot of the foliage. If the leaves die off, you need a palm that regenerates really fast. A Trachy will, whereas a Sabal or a needle might only throw a couple of fronds a season in the northern states, much to slow to ever amount to anything, all in all.

And, by your list, you pretty much have covered all of the bases.

The Pindos actually seem to grow pretty fast, too, compared to the Needle and Sabal.

The only thing I don't see on your list that would be worth experimenting in Ohio would be a European Fan, because they too tolerate cooler conditions and grow pretty well under them. They aren't as winter hardy as the Trachy's, but still worth some trial in Ohio.

Joe,

Ohio is split between zone 5 (-10ºF to -20ºF) and zone 6 (0ºF to -10ºF) on the current USDA zone map. On the "new" Arbor Day Foundation map, almost all of Ohio is zone 6, but a small area near Cincinnati and another small area near the West Virginia border are in zone 7 (0ºF to 10ºF).

I am wondering what makes your "good microclimate" never go below the 20's. That would put your land in a zone 9! That would allow you to grow a lot of palms and other subtropicals. How long have you been monitoring the low temperatures there?

Bill

Bill-
I'm saying a good protected palm wont go below 20's
By micro climmate I meant inclosed Area not literal
Micro climate.Sorry agqain I'm using bad word Choice.

- bill_ri_z6b
I'm right in that Z7 border By WV
Thats what I try to tell people but they don't listen.
I'm also located in a valley maybe 200 feet wide (Atleast for most of my half a mile drive way) there are trees that are full sized on both sides of the road and prevent wind
but plants still get full sun.

How long are you planning on keeping those Washingtonias? In a decade they will be taller than your house and impossible to protect. Like I said, even way down here at the edge of 8b they are heavily damaged right now.

Joe,

I see what you meant now about microclimate. As for the zone 7, that's only on the Arbor Day Foundation map. The official USDA map still has Ohio as zones 5 and 6. The trees you mention are good protection from the drying winds of winter, but being in a valley sometimes means that colder air, which is denser and heavier, can settle in low-lying areas. It might be best not to place palms at the lowest points on your land.

Bill

You can move to Arizona or S California. They'll grow fast down there. What about erecting a greenhouse?

Without getting into the debate as to your zone, for me "cold hardy" means something I can put into the ground and expect to survive without having to protect (by adding lights, blankets, or a dropping a greenhouse over it). In a zone 7, I believe the fastest "cold hardy" palms are Trachycarpus fortunei and probably Sabal louisiana. Washingtonias are faster growing but not winter hardy to zone 7 (without serious protection or modifications to their conditions).

Yeah I know but having things that people don't is fun!

try a filifera