(a version of this blog post first appeared on October 31, 2012)
Species name: Cucurbita maxima
Common name: giant pumpkin
Location: photo 1 from Veggie Gardening Tips (click HERE), photo 2 from McShanes Nurseries (click HERE), and photos 3 to 6 from The Daily Mail (click HERE)
The giant pumpkin is actually a completely different species of squash than the regular pumpkin. When young (or more "natural" plants that have not been bred specifically for their oversized fruit), they are a completely different colour than regular pumpkins (almost red) and a very different shape. They are often sold in the grocery store as an edible squash variety, and called many names depending on their general appearance: banana squash, buttercup squash, Jarrahdale pumpkin, Kabocha squash, Lakota squash, Arikara squash, and the Hubbard squash. The giant pumpkin species originated about 4,000 years ago in southern North America (southern Texas and northern Mexico, but also perhaps as far south as Nicaragua) but was transported quite early in human exploration to Europe where species like it were already familiar to them. Cucurbita as a genus also has a second area of domestication around Burma, and since that was one of the stops on the great spice route, it was one of the groups of species that had been used by Europeans for centuries.
Growing giant pumpkins is a bit of an art form. To get a giant pumpkin to turn giant, first you need the correct variety. If you've ever consumed a Hubbard squash, you know how "regular sized" giant pumpkins can be. Once you have the giant fruit producing variety, the plant still won't produce a big enough fruit to enter into any giant pumpkin contests. To ensure that, you have to get crafty: you have to convince the plant that any sugars produced on a branch of the vine can ONLY be stored in the fruit because they have no where else to go. Normally plants can shuttle sugars produced in the leaves to any storage organ in the entire plant using their network of phloem, or sugar-conducting cells. Some plants make tubers underground (potatoes), and some make starchy or sugary fruit above-ground. In order to ensure that your one favourite pumpkin grows to an enormous size, you have to take a razor blade, and veeeeeery carefully cut the phloem off of the stem in a ring. This normally would be absolutely debilitating to a plant, and is called "girdling." A girdled plant cannot recover, and will eventually die. But what it does in the meantime is prevent the plant from conducting the sugars produced in that one branch to any other part of the plant. Instead, the plant just stores all of it in that one branch, in your soon-to-be-gigantic pumpkin. Some people also swear by watering with a sugary solution, but that won't do anything other than encourage microbial growth around the roots. This might be beneficial for a while, but sooner rather than later a detrimental fungus or bacterium will take over and rot the roots. Not a good idea. Ensure that the pumpkin gets enough water (because if you girdled the branch carefully, the xylem or water-conducting cells will remain intact), and sit back and watch your pumpkin grow!
Believe it or not, the seeds of the giant pumpkin are reported to have medicinal qualities. Fry the seeds in oil then grind into a powder, mix with sugar, then suspend that in castor oil. Drink it, and if you've got intestinal worms they will be no more. I think by the time you've resorted to drinking castor oil you're in pretty bad shape and would resort to any treatment, but to me this sounds like a disaster waiting to happen. There have been no scientific studies to suggest that this home remedy is remotely successful in the treatment of any human disease. Use at your own risk!
Since today is Halloween, I couldn't possibly pass up one of the most awesome uses of giant pumpkins that have nothing to do with carving them into jack-o-lanterns. Giant pumpkin regattas. Yes, you read that right. There are locations that actually grow giant pumpkins to turn into really awkward kayaks, then have races in them while the "pilots" are dressed in ridiculous costumes. There seem to be points awarded for creativity in decorating your "boat," too, since some of them seem to have some rather unusual additions that wouldn't contribute to the aerodynamics of their vessel. Don't believe me? That's why I have pictures.
Pumpkins as helmets?! Not recommended.