Your plants in your Moshling Garden will take three (3) hours from the time it is planted for them to grow. You can either keep an eye on the time, or keep an eye on the recently added countdown on your Moshling Garden door in Your Room.

3 hours or under to go -> Your door will show 2 HRS

2 hours or under to go -> Your door will show 1 HRS

Less than an hour to go -> Will show the countdown in minutes