Anne Miller wrote:
It would be really great it the OP, Shayok form 2022 would come back and let us know how she solved the problem.
The problem solved itself, and I'm not totally sure through which mechanism. I planted four Red Mulberries in a 10' diameter enclosure in spring of 2023 and managed to kill all but the central one. This spring (2026) I noticed little green berry-like things on it with a white fuzz. Looking on the internet, I'm guessing that's what mulberry flowers/catkins look like. The website of the nursery I bought them from says male catkins are 2-3" and female 3/8". I'd say the "flowers" I saw were more like 3/8". They turned into bright red berries around 1/2" long and are now turning a very dark red. They are sweet, but I wouldn't call them extraordinary. Birds seem to like them. I've had better from a tree I found roadside (in a different zone).
I'm guessing the dark red is its final stage; funny thing is the seller's site says they take 8-9 years to make fruit, which ripen in August. (It's early July now.)
So it's less a likely a moneicious tree (having both male & female flowers) and more likely a female tree being fertilized by a nearby tree that I haven't seen.
I also tried to solve the problem by planting nearby a Dwarf Everbearing Mulberry tree from Stark Brothers in Fall 2024. It did not leaf in Spring 2025. However, in Fall of 2025 I noticed it sending up shoots from below. It did not do that in Spring 2026. So that didn't work.