Add potatoes to a large pot, then pour over enough water to cover potatoes by 1". Season potatoes generously with salt. Bring water to a boil over high heat, reduce heat to medium and cook at rapid simmer until potatoes are easily pierced with a knife, about 10 minutes. Drain potatoes.
While potatoes are hot, toss them with ⅛ cup of vinegar.
In a small bowl mix ¼ cup pesto, ⅓ cup mayonnaise, and the zest and juice from ½ lemon.
Drain any excess vinegar from potatoes.
Toss potatoes the bacon, green onions, and the pesto mixture until all ingredients are incorporated.
Transfer to a serving dish. Serve warm, room temperature, or cold.
Notes
Store leftover potato salad in an air tight container for up to three days.The amount of salt and pepper varies depending upon the type of pesto used.