Janet Laminack, County Extension Agent-Horticulture
One of the cruel aspects of gardening is that things don’t grow when you think they should. For example, pumpkins are for the fall! Let’s plant pumpkins in the fall or late summer for harvest now! Nope, pumpkins are cold sensitive, they don’t even like cool-ish soil. They are so sensitive that anything below 50 degrees could result in chill injury.
Pumpkins are proud members of the cucurbit family. They want day temperatures in the 85 and 95 degrees Fahrenheit range (who doesn’t?) and night temperatures between 60 and 70 degrees Fahrenheit. It complicates things that we refer to some cucurbits as “winter” squash and others as “summer.” If it doesn’t grow in winter, what does it mean? Winter squash have a hard exterior when they mature, plus the fruits won’t get damaged by a frost. However, the plant itself will take a hit. Summer squash have a tender rind (unless you let them get out of control). Pumpkin is considered a winter squash.
Some other cucurbits are squash, cucumber, watermelon, gourds, and cantaloupe. Botanically, pumpkins are fruit. Horticulturally, we categorize fruits and vegetables by how/when we eat them: main course or dessert. Seriously … this is what I learned in college. Tomatoes are botanically a fruit but horticulturally we consider them a vegetable. In fact, there is a Supreme Court case ruling that tomatoes are a vegetable. That sounds like a silly court case but when it occurred, fruits were taxed and vegetables were not.
Another trait of cucurbits is that they prefer to be direct-seeded. Sometimes I have even been known to indirectly seed. That occurs when I toss my old gourds and pumpkins into the yard to decompose. Of course, now I could put those in the yard waste container (for City of Denton residents) to be recycled (as long as they aren’t painted).
Squash and pumpkins will not always be “true to type” meaning that the seeds may not create the same fruit. It is still a squash of some sort, just not taste good or have the same shape or color. This is because of cross-pollination. When growing cucurbits, sometimes diseases or other factors can create discoloration which leads people to believe that their plant has cross pollinated and hybridized. Here’s my best explanation on hybridization. You have a pumpkin plant that produces fruit. The fruit is the pregnant mother who doesn’t change species. She will look the same every time she’s pregnant (all the fruit will look the same). However, the genetics of that offspring (which would be the seeds) could be different. You then plant those seeds and who knows what you will get if they have hybridized.
Therefore, my suggestion is to eat those pumpkin seeds you clean out of your jack-o’-lantern rather than plant them. Pumpkin seeds are delicious when roasted and are a great source of potassium and protein.
Have a horticulture question? You can email, call, or now text our Master Gardener Help Desk at firstname.lastname@example.org or 940-349-2892.