In the garden we have a very leggy mahonia which I am bringing down to
size by heavy pruning.

One of the long stems is almost touching the ground (now that other
supports have been removed) and is in a position where I would be happy
to see another one grow.

Can I simply loosen the soil and peg the branch to it so that, hopefully,
it will take root?

If not, what advice do you have please for propagating a mahonia?