How do I anchor an umbrella?
I have a childcare in my home and their outside area to play is in rocks and needs shade. I have several umbrellas, but one which is largerand is in need of an idea to stabilize it so it won't fall over. Right now I am using sand bags which are inside of old dog food bags. I did this because the sand bags do not last a winter and a hot summer in CA. The problem is in the past I have sewn the bags shut but this doesn't last long even if I use outside thread. Any ideas? They love climbing on them but the way they are the sand eventually comes out.