When is a private garden not private?

There is a model bylaw which states that: 

4 Damage to lawns and plants on common property

An owner or occupier of a lot must not, except with the prior written approval of the owners corporation:

(a) damage any lawn, garden, tree, shrub, plant or flower being part of or situated on common property, or

(b) use for his or her own purposes as a garden any portion of the common property.

At what stage do we consider (b) to be applicable? We have an owner who through some arrangement is maintaining common property. He is paid for it. In front of his unit he has this beautiful manicured garden with privacy hedges, exotic plants and ordained pots.

This is in contrast to the rest of the bulding which is in shambles with wild creepers, weeds and dead hedges.

So my question is is he in violation of 4(b)? The owner does not have exclusive use of this area.