Steve Thorn wrote:My Pakistan and another less cold hardy mulberry have died back previously.
Pruning them seems to increase their cold susceptibility. Since I stopped pruning them they barely have any dieback now.
I wonder if this might be the ticket.
I'm not sure what variety is outside the goat barn where I live - it was here when my landlady bought the property 10-12 years ago. This 40-foot tree has not been pruned except for a huge chunk that split off and fell on the barn roof before I moved in, and then a large split branch that fell off the year I moved here (2020). There is even a second split branch that really needs to be removed (for 2 years now), but hasn't been touched.
It's loaded with berries. Haven't noticed any die off (besides the splits).
I'm outside of Carnation, though higher up in the forested hills surrounding the valley, not the valley floor or in town. We are 30+ miles east of Seattle, and just 40-some miles from the nearest pass over the Cascade mountains, so we are typically colder, and wetter than Seattle is. So not too dissimilar to your climate, I would think r.
The attached pic are the mulberries on this giant tree as they looked 3 days ago. Little babies!