This time of year evokes seasonal images of black cats, ghosts, and PUMPKINS! Most of us relate to the large orange pumpkin that you can carve a ghoulish face into and scare trick-or-treaters. But actually there are dozens if not hundreds of varieties of pumpkins. These large orange distinctive fruits or winter squashes are scientifically known as Cucurbita (scientific name of the genus). But that specific genus has countless species, subspecies, and varieties that look (phenotypically) totally different from one another! They can be white, green, yellow, orange, gray, and every color in between. They can be smooth, bumpy, knobby, and everything in between. They can be less than one pound or weigh more than 2,000 pounds! This one genus has a ton of variety.
A pumpkin is a fruit that grows on a vine. They are typically planted in late spring or early summer for an October harvest. After a pumpkin seed sprouts, large leaves begin to grow on vines. Eventually, the vine blooms with yellow flowers. The fruit grows and matures throughout the summer. When the vines turn brown, the pumpkins are ready to harvest.
Pumpkins left in the field will be eaten by animals or they will decompose. The phenomenon of decomposition is a natural process through which nutrients are recycled back into the soil. Insects, fungus, and bacteria are decomposers that eat the dead tissue from the pumpkin and excrete it in a form that helps live plants grow.
In nature, dead plants and animals decompose and become humus. Humus acts like a sponge to help soil hold water. It also traps air in the soil and provides nutrients. Plants need air, water, light, and nutrients to grow. When farmers plant crops in the soil, the growing crops take out nutrients. The farmers can replace those nutrients by tilling decomposing plants back into the soil. Animals, insects, fungi, and bacteria all play a role in the process of decomposition.
This whole decomposition process can be a great teaching tool for students. The pumpkin of course doesn’t actually disappear. Over time, all of the pumpkin matter is eaten or broken down by other organisms – giving those organisms energy. So the matter is converted into other forms and/or converted into energy for those other organisms. (Remember the Law of Conservation of Mass-Energy! Matter is neither created nor destroyed and the total amount of mass and energy in the universe is constant.)
The surviving seeds left by a decomposing pumpkin have the ability to sprout and grow into a new pumpkin plant, continuing the pumpkin life cycle. Alternatively, pumpkins can be harvested for their seed so that farmers can go on to plant fields of them next year. Pumpkin seeds can also be pressed for oil or used for a variety of other purposes like roasted for human consumption or included in livestock feed rations.
Pumpkins are a great seasonal teaching tool for students and make a special holiday treat for Halloween, Thanksgiving, and other fall celebrations.
What is your favorite way to enjoy pumpkins? Pie? Jack-O-Lanterns? Roasted seeds? Let us know in the comments below!