In article , ned writes
but it would be well to wait until after
your last frost before planting.

I'd second Janet B.s suggestion that winter planting is quite
acceptable for hawthorn - provided they are locally grown plants and
not subjected to a weather regime other than they are accustomed to.
I've just been infilling gaps in my hedges with transplants removed
from overgrown areas within my own grounds.

I agree that winter planting of hawthorn can be an option, but the
original enquirer gave the impression that he was not very experienced
at this kind of gardening. Thus pot grown plants rather than open rooted
and spring rather than winter planting would help to lower plant losses.
--
Alan & Joan Gould - North Lincs.