Would you agree that the appeal of your property partly rests with how well you maintain your landscaping? If your roofer finishes your roof and leaves you with a lot of dead plants and dead grass, your property could lose some of that appeal.
You should require that care and preventative measures be taken to prevent and limit damage to your landscaping. Plants along the house can be protected by leaning plywood up and over them. Tarps and Visqueen can be used to drape over shrubs and grounds but should only be used in the areas being trafficked and worked. These coverings should always be removed at the end of the day to allow the plants to recover. The sun can have a devastating and smothering effect on all the grasses as well as the shrubbery.
little attention and care can go a long way towards the prevention of causing dead plants and grass. If the roofer does get careless or an accident takes place, he is responsible for the replacement of any damaged plants. The items and areas that need the most protection and how the roofer will go about satisfying all of your concerns as he proceeds with your roof installation should be discussed prior to starting the job.