I have 7 zucchini plants that have re-seeded in the garden from last summer - I guess due to the warm winter in Long Island. I transplanted and all the plants are doing well, but I have 3 of the 7 plants with zucchini growing bright yellow. It's not a question of blossom end rot or anything like that, as I've had that problem before. These are perfectly healthy zucchini, just growing bright yellow - how is this possible?
It could be possible that you have both yellow squash and zucchini in the garden this year. Oftentimes, birds are the reason behind the pleasant surprises we find in our gardens each year.