I don't know if there is any in Gharaga, but there is one in Duhail which is not too far from Gharafa. The nursery called 'Star Fish', near North Atlantic College.

The directions:
Assuming that you are coming from the 'Slope Roundabout' and going towards 'Markiyah Roundabout' you will take this roundabout Left then go straight. You will reach 'Duhail Roundabout', take it straight also [the one with traffic lights]. Again you will see another roundabout ahead, before you reach it you will see the nursery on your Right hand.

Good Luck