While looking at my mulberry tree earlier, I noticed it’s not showing any signs of slowing down for the fall (note the nice tender shoots at the top right and by my hand):
It started on a second flush of growth after being mostly defoliated in June/July by an enterprising groundhog. I had fertilized it twice since then, which may be contributing to the continued growth. We’re getting into frost territory here soon, and I’d prefer if it started concentrating its resources on hardening off the existing wood and buds for winter. Any way I can encourage it to settle down?
You can try pinching the growing tips. This has happened to mine in the past. Some were heavily damaged by winter cold when they failed to harden off sufficiently.
In my experience, Mulberries on M. alba rootstock are vigorous and resilient. I personally would let it deal with the consequences, especially if you have a back up scion or rooted plant.
Agree with Richard, mulberries are pretty tough, if there’s dieback on the tender parts, chances are that’s where you might want to prune it in spring anyway to obtain the best spatial distribution allowing sunlight equally to all parts of growth.
Let it go for now!
Dennis
Kent, wa
