I'm sorry to hear that your neighbors are not showing up right away. We rely on Facebook to connect your friends to our app.
Players who have experienced this say that the only work around they've found is to keep refreshing their browser. After a while, your friends will gradually be connected, but it can take some time. If they are a brand new neighbor it can take up to 48 hours to connect.
If you have NO neighbors at all, and haven't had any for awhile, it could be because your Facebook permissions have been changed. Please uninstall the game, then reinstall it. When you are prompted to adjust the permissions/settings, leave everything at default! Then wait 24 hours, and you should start to see neighbors reconnecting. This will NOT change anything on your farm - your data will remain intact. The only change will be that your collecting limits will be temporarily maxed out for 24 hours.
Remember that your neighbors must PLAY Pot Farm actively to show up in the game! If they are old neighbors who no longer play, they will not show up. To get more neighbors, visit our fan page at https://www.facebook.com/potfarm . There are lots of people who are looking for friends to play with!
Thanks for your patience.