How to Grow a Giant Pumpkin

With his record pumpkin weight of 1,384 whopping pounds and 20 years of experience under his belt, he's dominating competitions all over the West Coast. This pumpkin (above) weighed 1,289 pounds, the second-largest pumpkin he's ever grown.

Every year in the fall, Holland selects a pumpkin with promising genetics, harvests and dries the seeds, and the third week of April of the following spring, he starts the life cycle of the giant pumpkin all over again.

He explains how to grow a giant pumpkin:

Use a fingernail file to scratch the edges of the seed coat, then soak the seeds overnight in a paper towel. Dip the seeds in mycorrhiza for stronger growth and protection from pathogens that may be hiding in the soil. Pointed end down, the seed goes in about a half an inch from the surface. If the soil is moist, don't worry about watering until the seeds sprout.

An important thing to keep in mind when starting a giant pumpkin seed is to provide the right conditions for germination. Holland uses an incubation chamber with a temperature between 85 and 90 degrees. A simpler method is to put the potted seeds in the oven and turn on the light. (Be sure nobody turns on the oven; you obviously want to grow the seeds, not roast them.)

In about three days, sprouts will appear. Move the pots to a well-lit area. When the plant grows large enough, you can transfer them into bigger pots.

When the weather warms sufficiently (about the second week of May in Holland's area), transplant the plants into the ground where the soil has been enriched with compost. Holland adds mycorrhiza to his soil. Pumpkins like the soil kept slightly on the acidic side at a pH of 6.8. You can make the soil more alkaline with limestone or increase the acidity with sulfur.

Sometime between mid-June and mid-July, when the flowers open, the plants are ready for pollination. The female flower has a short stem and an ovary, or an immature pumpkin, behind the flower.

The male flowers are typically on a long stem without a little pumpkin behind the flower.

Gently roll the pollen off onto the different lobes of the female flower. Within 24 to 48 hours the baby pumpkins will begin to grow.

Holland uses garlic-based pesticides to keep down diseases like powdery mildew. As a plus, the odors keep hungry critters from munching on the produce.

Building a shade structure around your potentially prize-winning pumpkin is also a good idea. Protecting the fruit from weathering elements like sun, rain and wind keeps the pumpkin young and growing strongly. It also helps avoid cracks and splits.

Feed the pumpkin plant regularly. Holland applies a foliar feeding once a week. His heavyweight champions are fed on a seafood diet of fish and seaweed emulsion, washed down with deep watering twice a week.

The pumpkins need a lot of calcium, which makes for a nice, thick wall and strong cell development, which in turn also helps resist cracking and splitting. So Holland applies a calcium supplement as a foliar spray throughout the summer.

Proper pruning is also important if you want your pumpkin to make the cut. "We try not to grow salad but to grow fruit, so we trim a lot of the vines," he says. "We normally grow one long main vine and allow what we call the laterals to grow off of that. But each lateral would also try to form their own set of vines, called tertiary vines, and we take those off in the bud stage. So the pattern we end up with is called a Christmas-tree pattern."

To get the large size, Holland usually allows three to five pumpkins to set on the main vine and watches them for two to three weeks, slowly trimming back to what he thinks is the single best candidate or specimen.

By mid-August, the fruits will grow 30 pounds heavier and the vines a foot longer on a daily basis. By September, your prodigious produce could be ready to squash the competition. Often the pumpkins, though less than 100 days old, may weigh 1,200 or 1,300 pounds or more.

Once the Halloween season is over, there's not a whole lot to do with the giant pumpkins other than to retrieve the seeds.

"It's not as hard to cut as some people might imagine, but it is fairly thick flesh," Holland says. "The shell is a good 6 or 7 inches at this point. Toward the stem it's probably another 3 or 4 inches thicker."

Each pumpkin can yield up to 500 seeds. "What you don't grow the next year, you can always sell."