First, the mulberry can grow into a tree reaching 50ft/15m tall. Next, it bears more fruit if you prune it hard.
As I do not relish the thought of using a ladder to reach the berries each time they are ready for picking, it makes sense to maintain them at a reasonable height. My 20-year old bushes are still just about 6ft/2m tall.
Pointer 3 – When to prune a mulberry plant?
Pruning a mulberry plant will help induce fruiting.
1. If a cutting is long and there are no berries on it, prune it.
2. You should also prune after you have picked all the berries off a branch. Red mulberries are still not fully ripe and will be sourish. These can be used for jams and such, but if you want the berries to be fully ripe, they should be purply black.