The maid and gardener are there for players who would rather not take the time to clean up the house and the yard. If you have hired the maid and gardener, you'll have to look for wrappers, weeds, etc. as soon as you open the game in order to get to them before the hired help does. If that doesn't give you enough weeds and wrappers, you can fire the maid and gardener if you like.
Here is what it says about them in the game's store:
On Call Maid Service - A busy person's dream! No more stray wrappers and socks, ever! (They can be fired by touching their detail button)
On Call Gardening Service - Had enough of pulling weeds? Let your gardener do it for you! (They can be fired by touching their detail button)