I have several sawtooths that are about 8 years old. They have been producing acorns for about 3 years but they are only about the size of a pea. Not sure why the acorns won't/don't get any bigger but they have been like this for 3 years. I put triple 10 around them late last fall but didn't put a whole lot of it. Any idea what I can add to soil make them produce bigger acorns?
No clue......mine are a little over 10 years old and get "huge" acorns. I fertilized the first year and once they took off I haven't done anything to them......and I've got the poorest ground around !!
I think acorn size is determined by genetics. Your trees are probably Gobbler Sawtooth Oaks which have smaller acorns compared to the regular Sawtooth Oak.
Most of our Sawtooths grew really well, but it took them about 20 years to produce. We planted them in ‘97. This picture was taken last year.
Twenty years is about right for Sawtooth (Korean Oaks) to bear acorns. Had several in my yard up in Southern Indiana, only thing bad about them is they tend to grow with a "Double Trunk" which sometimes split if you receive a freezing rain event.