Best method for large Chinese elm cuttings?

[Michael P]

Some secondary and tertiary branches may need to be removed from an elm I've been developing for about 25 years. They are well ramified and I don't want to lose that work, but they are in very difficult places to air layer. The largest one is about 1/2" (1 cm) in diameter. Could these be successful cuttings and what would be the best way to do it, especially time of year?
Thanks in advance.

 

[Wires_Guy_wires]

I have done some elm cutting last winter, they were all about a centimeter thick at the least. Some going 1.5.
I had a strike rate of about 80% by dipping them in rooting hormone powder and jamming them in potting soil.

 

[Michael P]

Thanks! Did you protect them from freezing temperatures?