Answer:
This situation brings up a potential conflict of interest for you.
Explanation:
"A conflict of interest occurs when an entity or individual becomes unreliable because of a clash between personal (or self-serving) interests and professional duties or responsibilities. Such a conflict occurs when a company or person has a vested interest, such as money, status, knowledge, relationships, or reputation, which puts into question whether their actions, judgment, and/or decision-making can be unbiased. When such a situation arises, the party is usually asked to remove themselves, and it is often legally required of them."
Then you should ask to remove yourself from the new landscaping company decision making if your son's company is an option among them.
Reference: Segal, Troy. “How to Tell When's There's a Conflict of Interest.” Investopedia, Investopedia, 29 Apr. 2019