1) Bakeries. Frosting is shipped in buckets. These buckets are often smaller than 5 gallons, resulting in smaller water reservoirs. If you use the automatic watering system, you should be AOK. Wayne Burks from Anderson, Mo. writes, "I've been finding them at some Walmart stores that have bakeries. I get at least 5 at a time. Tonight I was able to get 9!"
2) Pickles. Deli pickles are often shipped in 5 gallon buckets.
3) Drywall Mud. According to Friedrich from Munich Germany, buckets that are used to ship drywall ("SheetRock") mud are safe. We express no opinion on the safety of using drywall mud buckets for a garden. Do not use them unless you have verified that they're safe.
4) Soap Makers. Make friends with a person who makes handcrafted soap. Vegetable oil, which is shipped in 6.5 gallon buckets, is used in the soap making process.
5) Mexican restaurants. I live near a Mexican restaurant which puts out their used buckets and lids weekly so this is a really good source. If you don't mind the fact that they are imprinted with the words Lard and Pork Bellies and of course you have to clean out the residual! I use the lard scrapings to make little eateries for the wild bird population in the winter. Sylvia from Norristown, Pennsylvania.
6) Fast Food restaurants. I find buckets at the Burger King on an Army base nearby. The pickles are shipped and as they empty the buckets they normally throw them out. Simply ask the manager to set them of to the side and you can pick them up at your leisure. David Lonowski US Army Irlbach, Germany
7) Electric motor rewinding shops get their wire in 5 gal. buckets. These are spotlessly clean and ready for use. They just junk them. Mike Connolly from Central Illinois.
8) Wine Store. "I found free buckets at a wine making retail store." Marcelle from Timmins Ontario Canada
9) Kitty Litter. I use empty cat litter buckets from myself and my friends. They have the right plastic rating and they work GREAT! Teresa
10) Cafeteria Lady & Craigslist. I found two great sources for buckets. 1) I asked the "cafeteria lady" at my child's school to save them for me (took a little patience but I got 6) 2) I found someone selling buckets for 50 cents each on craigslist.org (instant gratification they had hundreds - I bought 30) Shannon Fresno CA
11) Car Washes. I've recently discovered car washes, particularly the self serve car washes, have a large supply of buckets. The one near me has a never ending supply of 5, 30 and 55 gallon plastic buckets. Sam Aiello of New Jersey.