I removed a large bischofia tree from my yard, which included grinding the large stump down. However I keep seeing sprouts from the tree around the area of the stump grinding and throughout the yard. Here are some photos of the sprouts.
The disturbed soil is my attempt at digging up the roots. It took a lot of time and effort, but didn't do too much to slow the growth of the roots. The number and size of the roots are probably a contributing factor. Here is one of the larger roots that I dug up.
What can I do to kill the tree and stop it from continuing to sprout at different locations?
One caveat is that I would like grass to be able to grow around near the area afterwards.
I have used Bonide Stump Out with some success, but I'd like to keep using it to see if it works more.