Some normally-rational Whidbey Island residents spend a great deal of time and effort in their backyards pampering monsters.

They concoct special blends of food, build little shelters, measure out water, take temperatures and chart growth like doting parents.

They are among a growing number of folks nationwide who raise giant pumpkins. Dozens upon dozens of books and Web sites dedicated to the hobby proclaim that interest is at an all-time high.

“It’s kind of like golf,” said Dr.Lee Roof, a Coupeville internist and expert pumpkin grower. “You’re always trying to better your best results.”

Coupeville is one of the many communities across the nation that hold pumpkin weigh-in events each fall.

On Saturday, Oct. 8, people will be straining their backs hauling huge, misshapen fruit onto the scale during the Tenth Annual Whidbey Island Giant Pumpkin Contest, which is a highlight of the town’s HarvestFest.

While Coupeville is a pretty small community among the many pumpkin weigh-in sites, organizers expect big things this year. Last year, a total of 29 pumpkins were entered. Oak Harbor resident Phil Renninger broke the island record with his 739-pound giant.

It seems likely that the record will be broken again this year, though pumpkin fanatics are very hush-hush about what’s growing in their patches. It’s an odd kind of gourd paranoia.

In fact, giant pumpkin growers are an unique sort. Neal Amtmann of Coupeville admits that there’s not a lot of point to growing oversized pumpkins, beyond the moment of glory when crowds gather and jaws drop in amazement at the sheer bulk of the things.

“It’s not for a product,” Amtmann said. “It’s for a bragging right. It’s a big game.”

There are half-joking stories about grown men rubbing balm on the giants gourds, warming pumpkins with electric blankets when it cools, or injecting vines with syringes full of fertilized water.

“His pumpkins have never been tested for steroids,” Amtmann said with a laugh, referring to Roof’s behemoths.

Yet beyond the mysticism that surrounds the Halloween fruit, growing giant pumpkins does take a lot of time, energy and the right techniques.

Tom Walton, a West Beach resident, is relatively new to the avocation. He was halfway through the pumpkin-growing season when he purchased books on the subject and learned that he was doing a number of things wrong.

“There’s quite a science to it,” he said. “It can be quite an ordeal. Every day is an adventure in the pumpkin patch.”

Walton realizes that his 150-pound baby won’t win the weigh-in, but he’s optimistic about the prospects of winning the beauty contest.

HarvestFest offers awards in a number of categories, including most attractive. While most giant pumpkins flatten obscenely under their own weight, his bright orange gem is well-proportioned and has smooth skin.

Aficionados trace the lineage of pumpkins like one might track the bloodlines of a famous horse.

Roof explained that the hobby really got its start just 20 years ago, when a Canadian by the name Howard Dill created the Atlantic Giant. It’s technically a squash, though the line between pumpkin and squash are pretty fuzzy.

Since then, all pumpkins of great size spring from Atlantic Giant seed. But the plant genetics and growing techniques are continually being refined.

Twenty years ago, world-record pumpkins were around 700 pounds. Nowadays, the record is more than twice that. The pumpkins can grow 20 pounds a day. Some growers on giant pumpkin Web sites claim that they can actually see the pumpkins grow.

The reason that pumpkins can get so huge, Roof said, is that fruit have a lengthy growing period of up to 70 days. The key is to optimize the conditions during that period.

Roof offers many hints for growing giants, though he admits that he has secrets.

First of all, get seed from proven stock. Ask someone with a really big pumpkin to share. Plant in a well-composted patch — in full sun. Use the right type of fertilizer at the right time of year. That means heavy on the nitrogen early on and more potassium once the fruit has set.

“Pruning is very important,” Roof said. Each plant should have only one pumpkin and all the suckers should be cut off.

Walton said giant pumpkin experts suggest a drip watering system, hand pollination, building a greenhouse around a pumpkin, complete with fans and heaters, and on and on.

But even if growers do everything right, pumpkin patch tragedies occur quite often. Varmints gnaw and slugs gum up the plants. The fruit is susceptible to rotting or developing soft spots, holes and cracks. Sometimes they just burst wide open.

“It can be kind aggravating,” said Roof. “They get too hot and rupture or grow faster than their skins will allow.”

After the HarvestFest, some of the giants are carved into jack-o-lanterns and seeds are roasted, but most of them go the local farmers. They are healthy snacks for cattle, goats and other creatures.

You can reach Jessie Stensland at jstensland@whidbeynewstimes.com or 675-6611.