GOSHEN, Ind. — I’ve always has a fascination with pumpkins. Little, medium, large or gigantic; white, orange, green or variegated; warty or smooth skinned; flat or round; pie pumpkins or ornamental, I just love them. I don’t get hung up on the term “pumpkin” or “squash” as, botanically speaking, pumpkins are just another form of a hard-skinned winter squash.
One of my goals in life is to grow a giant pumpkin to contend for a record of some kind. I have managed to grow a 400 pounder with little effort, and it helped me understand the huge effort it would take to go to the next level. I sincerely doubt I will master a 2,700+ pound pumpkin, but it sure would fun to try. Think about that for a minute: a pumpkin that weighs as much as a small car!
People that set these records are somewhat obsessed with detail. It starts with the soil. Good drainage is a must, with long hours of sunlight, and access to plenty of clean water. Soil fertility is important, with many growers testing the soil annually and adding amendments like compost, manure, and adjusting pH to around 6.4 to 6.8 well in advance of planting. Better plan on some space for these giants too. A single plant growing one monster will take up 1,000 square feet!
The seeds and the genetics they contain are important and can be quite expensive, often for more than a dollar a seed. Most of the genetics stem from improvements made to a variety called Atlantic Giant. A whole genetic language has been developed to explain the contents of a seed. A seed labeled 1025 Reed X 1950 Andersen indicates the “female” the seed came from was grown by a person named Reed, and it weighed 1,025 pounds, while the pollen came from a “male” plant that produced a 1,950 pounder by a person named Andersen!
If seeds are to be harvested the following season, the plants are hand pollenated; the growers do not leave pollination up to chance when growing these big guys. As you can see, they also keep meticulous notes of their work.
Large giants require an early start. Typically, the grower will start the plants indoors in large peat pots in late April. About 10-14 days later, the seedlings are transferred into a cold frame, small greenhouse or floating row cover which protects them from frost.
As the flowers develop on the plants, it’s important to note that for at least a week, the first flowers are all male, producing only pollen. The female flowers emerge a week or two later. If you are not saving the seed, any pumpkin/squash pollen will do the job of creating a large pumpkin. The genetics in this year’s large pumpkin will express themselves in next year’s crop, and are highly unlikely to produce a large pumpkin.
Once pollination has occurred, the growers narrow down the pumpkins to 4-5 per plant. They try to keep these 15 feet or so away from where the main root enters the ground, because as the pumpkin grows, it will stretch those vines considerably, and the flexibility of space is crucial.
At around volleyball size, the grower will once again narrow the number of pumpkins down to only 1 pumpkin per plant. This allows the plant to pump all the nutrients into just one pumpkin.
The tricky part is training the vines and pruning the roots. Remember, this pumpkin will eventually stand several feet off the ground, and will lift the vines with it. Since the vines frequently root at the nodes, the roots on those nodes and vines must be pruned, or the growing pumpkin will dislodge the plant. At around 300 pounds, the grower may need to push the pumpkin back towards the main root system a few inches to avoid vine damage.
While all that is going on, the normal work of avoiding weeds, insects, and diseases continues. Water is especially critical. Pumpkins require about 1 to 1.5 inch of water per week, even more when it’s extremely hot. Most competitive growers will use trickle irrigation or soaker hoses, since overhead irrigation wets the foliage and can encourage foliar disease issues.
While the plant leaves need sunlight to manufacture food, the pumpkin itself needs some protection from the sun. Old sheets or burlap cloth are often strung up like tents to prevent premature hardening of the skin. This allows the fruit to grow to its potential.
Finally, the day comes to move the pumpkin. Those under 400 pounds can usually be moved by a few friends, a tarp and a free meal. However, above 400 pounds requires some serious planning. It is not unusual for growers to place their prize winners on pallets early in the season, so they can use forklifts and heavy-duty straps to gently move the large object into a pickup bed or a trailer.
Sadly, our Elkhart County 4-H Fair horticultural contest is held too early in the season to hold a largest pumpkin contest, but there is some great competition at fairs held later in the season like the St. Joseph County Michigan fair.
–Jeff Burbrink
Extension Educator
Purdue Extension Elkhart County
