How can I use large plastic pretzel containers in my backyard?

Oooh! You could add drainage holes in the bottom and use them as planters! And you can paint them in fun colors :)

Put plants in them put lights in them make a terrarium in them

I used to take any large containers that I had in the spring and put small holes around them then sink them in the ground around and between the plants in the garden. I would then put my fertilizer water in the containers and put the lids on them to keep the bugs and animals out of them. They worked well for a slow release watering system without having to purchase soaker hoses and all. Note that I only put fertilized water in the containers as recommended on the fertilizer label, the rest of the time I used just water. I checked the containers once a week or more often in really dry hot weather to see if they needed to be filled again.

Pretzel containers have bothered me for the longest! They are sturdy and surely can be used for something! The smaller ones can b used in the garage. Take a 1x12 board, screw the lids through the underside of the top. Fill with nails , screws, etc and screw onto the top. Hang your shelf either with two pieces of wood you can screw it down to , which means measure your 1x12 or with braces. I guess you could use the large ones for larger stuff like steel wool( i refinish things). Good luck!