Q: I’ve noticed that over the last couple of years I’ve had one or two cucumbers that stay a yellowish color and never turn green.
Is this due to a cross pollination with a squash or some other plant?
A: It’s not the fault of cross-pollination unless you are saving seed from year to year. In that case, pollen from a compatible plant might cause the seed to produce odd-looking fruit.
But if you planted seed from a package or from store-bought transplants, pollination would not affect the fruit this year.
Indeed, there are yellow cucumbers (‘Lemon’ is one variety) but they resemble a yellow baseball, not the oval cucumber shown.
Your cucumber simply looks overripe. In hot weather, cucumbers quickly go through the last part of their green ripe phase.
Yellowing skin is just the next step to maturing the seed so they can spill from the fruit when it rots.