Mulberries for very little chill (Zone 10)

Does anyone have good experience “zone-pushing” up for mulberries?

Productive mulberry specimens abound in my zone 10a location (E SF Bay Area), including nigra varieties, Pakistan, and various albas (and/or hybrids). Morus nigra and macroura are both known to do well in zone 10 and are usually listed by nurseries as such. There seem to be many alba varieties listed as such too. I’ve seen rubra listed to zone 10 too (eg Varaha), and possibly some hybrids (tho I can’t recall any).

The question is: How might more cold-hardy varieties like Kokuso (morus latifolia) or Illinois Ever-bearing (alba x rubra) do in Zone 10? I’ve seen both listed to Zone 8, and I’ve seen Kokuso listed for Zone 9 once—but never higher. I’d love to try Kokuso in particular for a windy spot, as I have heard its fruit hang better—but don’t want to waste my time if production will be poor.

Are there any folks here who have successfully zone-pushed the more cold-adapted mulberries in Zone 10? If so, how has productivity been?

I’m also interested to hear general thoughts on zone-pushing up. I’ve read several threads on this forum on zone-pushing in the other direction, but not much discussion on pushing up.

Thanks in advance

I’ve not had eyes on Varaha in person, but from photos I’ve seen, I’m pretty sure that it’s a hybrid, and not the pure M.rubra they claim.
My two youngest kids live in The Highlands area of Louisville, where Varaha supposedly originated. That area is overrun with trashy M.albas that would have contaminated the local mulberry gene pool many, many years ago.


I have noticed this one youtube… 9b.

Jan’s best… fruit sure looks nice… lots too.