I've had a generic morus nigra in the ground for two years. I bought it as a tiny little thing on its own roots in a gallon pot, and it has grown very well. Still no fruit though.

Last summer I put in a large 15 gallon grafted speciman of "black beauty". It had some fruit when I bought it, and man were they good... much larger and tastier than the native morus rubra or non-native morus alba.

I've learned the following about these plants:
-- They're very late to start growth in spring.
-- They're also reluctant to slow down in fall if well watered, thus in my climate they are susceptible to early fall freeze damage.
-- They can resprout easily from the roots and add plenty of growth by the end of the season.
-- Growth that is thick and/or properly hardened off seems to avoid any cold damage.

Mulberries should fruit on new growth, so some winterkill doesn't bother me. Your climate should be fine, especially since your transition into winter is more gradual than some. I don't know about the various cultivars other than the common "black beauty", but the word is that even the species is among the best for taste.

Good luck!

Yes, I will second the growth observation. My Noir de Spain is the last plant to get leaves in Spring, even after persimmons. And my tree right now at winter solstice still has most of its leaves, although they have now gone from green to yellow with crispy edges.

Carla in Sac

Said to be hardy to 10 degrees F. Seldom seen even here in western USDA 8, although there are a few of some size, including one about 20' tall on a Seattle street.

Last year I sampled fruits from one next door, as the neighbors were out of town at harvest time and said I should help myself.

To my surprise, considering the raving over them I have encountered (and passed along here) I found them unappealing. Slightly bitter until dead ripe, at which time they became shrunken and partially melted in texture - and without a stunning flavor at all.

Hardly worth the trouble - and I have attempted more than one mail ordered specimen (each with a different cultivar name) on the Island County, WA property without having the plants take. ~40 bucks each plus shipping, only to have them leaf out and then just sit for one or two growing seasons, later die completely.

The one next door was bought locally, as a fairly large top-grafted specimen.

bboy,
I wonder if the relative lack of summer heat and/or the soggy winters in Seattle might account at least for the poor taste of the ones you sampled? I've seen in more than one place that they prefer things hot and dry.

On the other hand, both M. rubra and M. alba are known for variability of fruit quality from tree to tree, and even from year to year, so maybe this is true for M. nigra as well?

Bitter? Maybe your neighbor's top-worked tree is not a Nigra, because Morus Nigra are the MOST delicious thing ever when ripe. It's true they are tart until dead-ripe black, but then they taste of really sweet blackberries combined with Merlot wine. But even when tart they are good to cook with, and they are never bitter. As I have written here, I have found strangers climbing my tree to steal the fruit, they are so good.

Carla in Sac

I do not confuse white mulberries with black mulberry. Their leaves and growth habit are really quite different. The tree is growing there because a person who raves about black mulberry fruits is a Seattle horticulturist, I gave a copy of or pointed out to them one of his articles about trees he thought people should plant in this area.

Black mulberry has also been an RHS Award of Garden Merit plant, kinds not doing well in cool, damp summers are not likely to get the trophy from British gardeners.

bboy,

Maybe this is just a matter of taste... not everyone likes mulberries, or any fruit for that matter. In terms of the RHS thing, doing well in a climate and meriting that kind of attention may have nothing to do with fruiting (after all M. alba is planted so widely as a fruitless tree, even though some varieties of the species have excellent fruit potential).