Last year i had planted 4 mulberry trees outside but slowly they all started to die. I figured it was the soil. It was badly compacted. Eventually, i was left with just one which i decided to pull out and put in a container. Soon after, that one died too or atleast i thought it did. A few weeks after, new shoots started to emerge from the base and now, THIS. A mulberry tree with 7 trunks including the main dead trunk in the middle. It's taking the shape of a shrub more then a tree which I've never seen with a mulberry tree. Question is, what should i do? Let it be the way it is or find the strongest cane and prune everything back to the ground?
Those sucker shoots can all be usable. You could top them as bush so that they will send out side shoots for berries, or cut all but one to the ground if you want it to grow as a tree. The center, dead shoot can be cut back to the ground.
Mulberries need to be in the ground, and not grown in pots. They prefer their roots to spread laterally. Too much fertilizer will cause them to grow more vertical shoots with few or no berries. That has been my personal experience when I planted one next to my garden. For mulberries, a little neglect is good.