You don’t want your Golden Hubbard Squash to cross-pollinate or you won’t have these beauties next year.
One of the most valuable things open-pollinated and heirloom vegetables offer gardeners (and the world) is the ability to produce “pure” seed. In other words, the seeds collected from open-pollinated plants, once planted, will produce replicas of the parent plant.
While it’s true that the genetic codes are very slightly altered, we can still rely on a reasonable reproduction of the plant. This is desirable because we know how the plant will perform in our gardens and how the fruit harvested from that variety will look and taste.