Concrete Pots How Do You Make "cement Or Concrete Filled Containers To Hold Flowers Outside On Tables For Weddings As Decor.

How do you make "cement or concrete filled containers to hold flowers outside on tables for weddings as decor. - concrete pots

I need to do something for flowers and arrangements to bases outside the balloon as decoration for the tables. I need something heavy enough not to fall. Can I use cement or concrete in a certain way and has the best job. I just want to fill the jars with the "glue" and then place small balloons and flower arrangements inside. These will be used for various occasions. What are your suggestions?