Sorry I didn't read your post earlier bberry. I don't
know about Mirabelle plums but yes you can grow Mulberries
in Maine. I live in Randolph (across the river from Gardiner) and I have two White Mulberries that are now
five years old and completely Winter hardy. They fruit very
well as a matter of fact. I got them from St. Lawrence
Nursery.

Here is a link that might be useful: St. Lawrence Nursery

OTH Gardener,
Glad to hear the white mulberries are doing well. I checked at St Lawrence nurseries and they do not offer any mulberries on their website. If you have any sprouts I would be willing to trade Montmorency cherry sprouts. I have many to trade and they never fail to give me all the pie cherries I want. I have not heard from anyone on the Mirabelle plums but I am sure they will grow here. Send me an e-mail if interested.

When I lived in Norway, ME my neighbor had ( he must still have it) a giant mulberry tree. I'm talking huge shade tree! the berries were yummy and large.