Black Poplar seeds (never got any)

[mvgulik]

I had some black poplar tree that never gave any seeds. (w16.0)
Think it matured in spring (mount bed placed in winter). At which point black poplar's don't have any seeds.
All trees do seem to give seeds in the first half of summer. But this one ... did not. (now already Autumn and still no seeds)
Stunted ... Not accord to Green thumb, as that did nothing.
(... its now chopped down.)