Fall is the time of year when we hear stories about the “cukamelons” and “zucchalopes” that grew in someone’s vegetable garden. Scientifically speaking, some plants will cross-pollinate with others. However, crossing is limited by differing numbers of chromosomes in the parents, which is referred to as species incompatibility. What vegetables really do cross with what?
Cucumbers don’t cross with watermelons, cantaloupes, pumpkins or squash. And cantaloupes don’t cross with cucumbers, watermelons, pumpkins or squash. Summer squash varieties will cross with each other and with pumpkins, but not with winter squash.
Things like “zuccapumpkins” are possible and more likely to occur if you save your own seed. Note that even though a cross may occur, the appearance of the fruit won’t change until you plant the seed from the cross, and it produces fruit the following season. Thus it’s improbable, but still possible, that seed purchased from a seed company carries such a cross.
The only cross that can show up the first year is corn. Sweet corn can easily cross with field corn, which produces starchy-tasting corn the same season.