Gas clouds are made of light molecules that a plant would need a large mass to retain, perhaps. Consider how Earth's gravity isn't strong enough to retain He.
After the planet has formed, yes. You need something Jupiter mass to already exist as a dense planet to retain those gases that way though. Before that forms the gases disperse too easily so you never get to the Jupiter mass planet stage.
It's only if the mass of the cloud in it's dispersed state is significantly greater than that of Jupiter that it's gravity is strong enough to prevent it's constituents maintaining dispersal due to their own heat.