It’s the bees.
Squash is a member of the Cucurbitaceae family, one of the most difficult vegetables to save seeds from. Cucurbitaceae have both male and female flowers and lots of wild, inedible relatives. Cross pollination is what Cucurbitaceae want to do. If you want to save seed and you take the precaution of taping up the flowers, bumblebees and solitary bees can chew their way through the tape to get at the pollen. In short it’s really easy to breed a freak Frankensquash or Frankencucumber, which can actually be toxic.
Cynthia, a Root Simple reader in Texas, alerted me to an interesting hazard with bitter out-crossed Cucurbitaceae. According to Tony Glover, regional extension agent at the University of Alabama,
The bitter taste of squash and cucumbers comes from a natural organic compound called cucurbitacin . . . which can cause severe stomach pains. If the fruit are extremely bitter you might as well pull the plant up and start again because they will not likely become un-bitter.
Cross-pollinated freak seeds are the culprit. And even reputable seed companies can screw up, especially with Cucurbitaceae.
Glover goes on to note that mildly bitter squash could just be a symptom of stress: heat, cold or lack of nutrients.
Have you ever had problems with unintentional freak vegetables? Cynthia’s mishap was with a “Long of Naples” squash a.k.a. squash baby, just like the one pictured above. I’m hoping not to have this problem!