This video demonstrates how cemented an umbrella into the ground.

This pool umbrella was held in place by sand bags which was covered up by a black plastic box. This killed the grass around the box and caused bugs and worms to come up from under the black box.

I cut and modified the original base for the umbrella and dug a hold deep enough to bury it in concrete, level it out and then reinstalled the umbrella. I hope you enjoy.