Location is Portland, OR
This was tip-pruned a year ago (not by me) and all the pruned tips sprouted these long shoots with leaf clusters only at the ends.
This is supposed to be a dwarf, but if it keeps doing this it will outgrow the area in which it's planted. None of the images I can find on the Internet exhibit this growth habit.
What is the best way (healthiest for the tree) to deal with this, keep it in its lane, and prevent "outbreaks" like this?
One thing at a time. Use the eye of an artist to bravely and completely remove any wayward branch that distorts the tree shape. Concentrate on a left-right balance whether symmetrical or not.
Here is your core tree shape that is begging you to prune anything else off at any time soon:
As for why you get these scary shoots, there is the bizarre possibility that the grafted trunk or root stock are breaking through to display their DNA. Not really, but more likely than a Halloween prank.
