IF the guy speaks no english you are already one up on this dude. He likely works off any payroll and may even be illiegal or is working with illiegals. Highly common in landscaping business. So it could be a risk to confront him as some people that are not from the US may become confrontational in a situation like this. Maybe you should cover them girls with some thin netting and tie it real tight and stake it down and put a note saying not to disturb the netting because the birds or something. Either way make it clear you do NOT want the netting messed with. And make it to wear he can't move it and it not be noticed. This way your being cool, and clear about it, and not threatening his job.
Just a thought. Either way maybe you should move on to greener pastures. I would never live in a home where I don't do the landscaping. If your a green thumb in any way this should be understandable.