It is hard to call this a project at all, as there is nothing to build and no tools involved. I had seen this done in a number of places and there are even custom-made water globes that you can buy for large sums of money.
Our heat wave continues apace today so I figured I would would give our new, large containers a bit of extra help. Containers often dry out quickly in the hot weather, so many help I can offer will help, I am sure.
Wine bottle waterer
You just fill up the wine bottle with water and then quickly up-end it and press it into the soil. The water doesn’t simply pour out as you might expect, but slowly gurgles down, directly to the roots of the plant. In my case I saw a little air bubble rise every couple of minutes, so the water was draining quite slowly. I will check in the morning and see how much is left and then I will get a better idea of how well they are working to keep the containers moist.