I have a native mulberry tree that a friend dug for me off his farm. It is now about 4 years old, 8 ft tall,  and putting on its first real crop. The berries are wonderful tasting, but very small. Does anyone know if the berries will get larger as the tree gets older? Most of them are only pencil eraser sized.

Gene,

Is it loaded with fruit or just a few small ones?  If it is the latter it could be a male......they still produce some fruit on some varieties but they are sparse and very small.  Is it a white mulberry or?

We had a native tree in our backyard in Virginia, and I recall the berries being a bit larger in diameter than an eraser, and 3/4 to 1" long.  Like a stretched blackberry.  It was a mature tree, though.  I don't know if fruit size is normally small in immature mulberry trees.

Have you considered grafting a few different varieties onto it while the tree is still young?  Whether the native turns out to be a winner or not, there are many prized cultivars that inspire mulberry freaks who are almost as odd as a few fig lovers I know.

Good luck

Does not sound like a male......if it has that many fruit i'm afraid that is what the tree produces and they won't get any larger in subsequent years.  

Agree with WillsC.  They likely will not get much bigger, if the tree is that size and producing well. Could very well be a Morus Rubra they are abundant in that part of the country and actually our only native mullberry although Alba is naturalized.  I spent half my childhood climbing a fence row of Rubra mulberry.  You might not want Pakistan in your location. It's not real hardy, both mine died this winter.

Hi Genedaniels,
I would try to fertilize the tree - if you haven't already done. It can only help . Fertilizer + watering .
Photo of a mulberry ? - to see the size .