Dan Kaiser said:

My Mulberry tree produces white fruit. They really have little or no taste, but
are very sweet. Is this, indeed, a type of Mulberry?

Possibly Morus alba (white mulberry) which can be anywhere from white to red
to deep purple when ripe.

M. alba very winter hardy. M. nigra is best for fruit quality (from everything I've
ever read) but is not reliably winter hardy in the north.

M. rubra (red mulberry) is a North American native that has unfortunately been
nearly eliminated by hybridization/competition with M. alba.

I make jelly with mulberries (black-ripening M. alba) every year.
--
Pat in Plymouth MI

Any technology distinguishable from magic is insufficiently advanced.
(attributed to Don Marti)