depends on your chosen fish. in theory you dont vacuum a planted tank as the poo breaks down into plant food (nitrate mainly)
however if like me you've over done it with big poo machine plecs etc.. you will have to vacuum. you dont dig in the gravel though just swish it about 1/2 inch from the substrate and you'll get most of it up.
As Jimbooo says - it basically depends on your fish/plant ratio.
I never vacuum mine but I am overfiltered, have substrate heating (this helps convert the nasty into good), have plenty of scavengers (Amano shrimp and Malaysian Trumpet Snails) and have high plant biomass/growth.
Obviously a heavily planted tank becomes harder physically to vacuum due to lack of visible substrate.