Hi perryalexander,
I have moved your post to the thread about Super Neighbours.
You should not be able to access their storage to plant any trees or use anything else that they have in there. You should be seeing your own storage when you open it and look in Item Storage.
Are you using a saved bookmark in your browser to load the game?
Please try closing the game where it is open in your browser and then use the Play in Farmtown button at the top of the forum to load the game and see if you still have access to use Items in their Item storage.
You can also try clearing your FT memcache. To do that
Click Here. A window will open with a list of "unsetting", that is the memcache being cleared. Close that window and FT if you have it open in another window. Then reload and see if that corrects it.
If after trying those, you are still able to plant trees from their Item storage, even if it's only one by one, please report this to the
support team.
To be able to use the Multi Planters that you or they own you need to have the permission to design a specific farm and also have the permission to "Allow buying and Selling with my coins". With those tools and permissions you can use the farm owners coins to buy and plant trees that are unlocked for their level in the store.