I had a bunch of egg cartons and I got to thinking about what I could do with them and I realized that they would be a better 'filler' for some of my big pots...
Ever have a really attractive, big pot that you want to use, but the plant you want to put in it is a bit on the small side (but will grow bigger)? I have, and I placed small nursery pots turned upside-down to fill in some of the space so that I'm not wasting quite so much dirt (and to give some drainage space at the bottom).
I don't love wasting the form pots, though, and I would love an option that breaks down over time so that it is more eco-friendly...
So try cutting egg cartons into thirds or halves (depending on the size of your large pot) and set them in layers on the bottom of the pot, fill with dirt, and add your plant!
If you try it, write below and let me know what you think!
(Edited to add - if you want it to break down, make sure your egg cartons are the cardboard kind, and not styrofoam. I always encourage people to purchase eggs in the paper/cardboard cartons anyway to discourage manufacturers from using styrofoam, but if you purchase your eggs in the styrofoam cartons, your re-using the cartons for this purpose will provide you with a more permanent 'raiser' solution and the re-purposing of them in this fashion is a better use of the cartons than simply throwing them away! Remember, breaking/cutting styrofoam is better done in well-ventilated areas.)