The xmas trees only generates coins every 24hrs, you will be able to collect coins from the trees only if you happen to collect it before someone else does or before the owner of the rown does, is very rare to be able to collect them, only if you are lucky enough, is better to actually pay more attention to the town, if you see that the person has a tree, go check on the simpsons house, if it has xmas lights on, it will give you a xmas coin, usually a person have 3 houses that are lighted up, if they have only 1 or 2 houses, focus on the simpsons house, collect the coin, exit, wait like a minute, and then go back into the town and i will let you collect again from the simpsons house, do this until you max out the 3 times. Hope this helps.