Do you need two squash plants to pollinate?

You don't necessarily need two of any cucurbit to get pollination; as long as the pollen is transferred from the male flower to the female flower, they will self pollinate. Breeders & seed savers often "self" cucurbits (pollinate with a flower from the same plant) to get pure seed.

Why do my squash plants have flowers but no squash?

When plants are thriving but fruit isn't being produced, it could be due to female flowers not being pollinated. Summer squash need insects, like bees, to pass the pollen from the male flowers to the female flowers. ... Male flowers have longer straight stems, while females will have a bulge just below the flower petals.