sheltered from wind and sun, just half an hour, hour or so of early morning sun. The older branches I stuck in pots just like that. Some 6 or so herbacious branches enclosed in a plastic bag.
It sprouted once before. I think I pulled the sprouts off in May or June. It's time to cut back all my other mulberry stumps anyway so hopefully if I pull the sprouts off again it will go back to being a stick.
I think Mulberry is in the fig family and figs root easy. Still, why not do the air layer route? Also our American Red Mulberry is a self fertile fruit tree meaning it will still fruit without a male but th fruit will be seedless. I happen to have a gorgeous shoin sized red mulberry thats ready to fruit for next year. I will get a picture of it later on as its in the ground now for winter.
Mulberry's are super easy to root. Last year I took down my Black mulberry Morus Nigra. It was too messy with the fruit. I did take cuttings, about 1.5" diameter stuck them in a pot and they have grown roots. I took the cuttings while the tree had fruit on it. No root hormone. The black mulberry has much smaller leaves than the White mulberry Morus Alba. I do have a white mulberry but it's a shade tree and fruitless.
Do not feel like entering discussions on this with my wife, who initially wanted to get the tree. She does not really like bonsai, nor pruning trees. So not a route I initially wish to take if there are viable alternatives.