There are certain relationships that are extremely important to maintain. Being a good neighbor is of paramount importance from a values perspective.
Like in a marriage, good communication among neighbors is essential because there are many things that a neighbor could do that would have negative impact on your quality of life. For instance, a neighbor playing loud music will be disruptive to you. A neighbor's kid playing basketball in the early hours of the morning will be detrimental to your sleep. If your neighbor doesn't maintain the upkeep of his house it could affect your property value in negative ways.
In the case of your neighbor strongly objecting to you planting a certain type of grass, I would caution you from doing so. Legally speaking, you are likely within your rights to plant this type of grass. If and when it grows onto his property and overtakes his lawn, he will have a legal case against you. However, why not work to maintain good neighborly relations and acquiesce to his objection. I'm sure you can find an alternative grass type to plant that will look nice, but will not be so unruly as to overtake his lawn.
Jewish law is full of property rights and case law involving harm done by one neighbor to another. But in terms of Jewish values, I would recommend taking the moral high road and being a good neighbor.
Answered by: Rabbi Jason Miller