The suspiciously named Mr. Brown Thumb from Chicago Now’s Chicago Garden blog offers a simple but valuable tip for gardeners looking to cut down on their water and soil use: Don’t waste water-sucking dirt to fill your enormous pots.
Instead, opt for a filler concoction. Mr. Brown Thumb suggests water bottles covered with newspaper (I just knew those things must be good for something!):
I filled the bottom half of the pot with empty plastic soda bottles. In total there are six 2 liter bottles acting as a false bottom in each pot. Then I covered the top of the empty soda bottles with newspaper, but you can also use landscaping fabric or something like cheese cloth.
Use the trick and you’re saving the environment in so many ways that you’ll lose count and risk having your head explode. And with any luck you may just grow that plastic tree or newspaper vine of which you’ve always dreamed.
Water and Money- Saving Tip for Large Garden Planters [Chicago Now]