In early October, when a truck with 4,000 pumpkins showed up on Amsterdam Avenue, around the corner from Hillary Wallace’s Upper West Side brownstone, none of her neighbors were surprised.

That’s because Wallace has become known for transforming the front steps of her 135-year-old home on West 82nd Street into a stylish Halloween haven — every spooky season since she bought her place eight years ago. 

She estimates that this year’s eek-inducing installation ran her $4,000 — much of that spent on seven pallets of pumpkins she purchased at auction in Pennsylvania.

No tacky animatronic props, faux spiderwebs or plastic monstrosities for this fearsome, fun-loving homeowner, however. Instead, spectators will be shocked by the two massive eyeballs keeping their terrifying watch from either side of Wallace’s front door — sourced from a wholesaler in Atlanta, and painted red around the edges by an artist friend to make them look scarier.

“I’m calling this ‘Someone is Always Watching You,’ and it’s this mystical, New Orleans potion theme,” Wallace, owner of Simon-Wallace Design, an interior design firm, proudly told The Post.

On each of the 12 steps leading to the front door, there’s a variety of gourds in exotic shapes, colors and textures, including some that were grown in silicone molds to form faces. (If you look closely, you’ll see a few Draculas and Frankensteins stacked in the stylish display.)

It’s all about the details, Wallace said.

“We spend five days going through everything, from where to place the bugs and how we wanted the rats to look on the trees,” she said. “I’m out there in my overalls, climbing trees and making sure everything looks perfect.”

Wallace’s decked-out décor is part of a trend sweeping the Big Apple and environs, where the house-proud are splashing out hundreds to thousands of dollars to one-up their neighbors on the most frightening night of the year — even if they have to hire someone to give their stoops their menacing makeovers.

There’s even a name for the new service: pumpkinscaping.

Bronxville homeowner and Halloween lover Katie Petruzziello is one busy area mom (of three) who opted to outsource the custom creation of an impressive 50-pumpkin pile she’s laid on this year in front of her handsome, century-old suburban home.

Petruzziello, who works at PricewaterhouseCoopers and moonlights as a children’s book author, said it was a no-brainer to hire Gia D’Onofrio, owner of Platinum Porches, a pumpkin concierge design, delivery and set-up company in Eastchester, to zhuzh up her front yard.

“This is so worth it because I didn’t have to carry the pumpkins to the car, lug them to my porch, and figure out what to do with them,” said Petruzziello, who spent around $450 for the setup, which will accessorize her front steps until Thanksgiving.

“Anyone can buy pumpkins at a supermarket or pumpkin patch — but the way Gia styles and stacks them is so gorgeous.”

D’Onofrio is one in a growing number of people cashing in on the trend — to date, she’s decked out over 70 homes in Westchester, with customers paying a range of $325 to $1,000 for the design of a layered, stacked look, delivery and set-up.

For an extra fee, she’ll even tear the whole thing down — retrieving the entire display and composting the pumpkins, assuaging any potential eco-worries of her guilty, go-go clients.

Across the Hudson River, Realtors Samantha Zoller and Emily Gonzalez have found sideline success as co-owners of the Entry Edit, a seasonal porch styling company in Mountainside, NJ.

“Busy parents in dual-working households don’t have the time to go out and buy all these pumpkins for their front steps,” Gonzalez told The Post, adding that rates for their cascading pumpkin set-ups range from $400 to $1,200.

“What we do involves a lot of heavy lifting and coordination. Our customers love seeing how amazing their porches look — and they don’t have to lift a finger to create this look.”

For some, the festive piles of pumpkins aren’t quite enough. That’s where Marc Evan, co-owner of Yonkers’ Maniac Pumpkin Carvers, steps in — knife at the ready.

His intricate carvings are beloved among his well-heeled clientele in brownstone Brooklyn and Manhattan — Evan told The Post he’s had to sign many an NDA when taking on a custom carve-up, which can cost clients into the “couple of thousand dollars.”

“We do museum-worthy works of art, and these pumpkins light up the porch and become a star attraction for our clients,” said the serial squash stabber, whose company was featured on “Shark Tank.”

“I think the trend toward having portraits carved in pumpkins is a natural evolution of the craze surrounding all things pumpkin — and Halloween,” he told The Post.

On the Upper East Side, lifestyle influencer Kristi Hemric’s seasonal stoop displays have become the talk of her block of East 78th Street off Third Avenue — and far beyond.

For the photographer, videographer and mom of four, one Halloween display isn’t enough — she began unveiling the first of four themes in August, amping up the scary as Oct. 31 gets closer.

And while she wouldn’t reveal how much she spends, a stroll past the beautiful five-story home she shares with husband David and their children makes it clear — this doorstep diva’s not skimping on anything.

Hers is a dazzling display, venturing beyond just pumpkins and featuring railings lined with black leaves that light up, tombstones, books of potions and white ceramic skulls.

And even though the 100 oversized custom LEGO flowers that Hemric ordered for the final Halloween display are stuck in transit, she told The Post her spirits remain high.

The improvisational wizard has pivoted to updating the colorful LEGO blossoms she used for her Mother’s Day stoop setup — with black bricks, of course. 

“The big element isn’t there,” Hemric apologized. “It’s OK — we’ll just use them next year.”

Back across Central Park, Wallace said her Insta-ready stoop not only forges community spirit, but it makes people happy, too.

“My office is two floors above the stoop, so I can hear people talking about it,” she said, adding that the students at the French school down the block give her an extra reason to smile.

“I keep hearing them count how many cockroaches there are in French, and now I know how to say that word!” (It would be “le cafard.”)

Delighting passersby is reason enough for Wallace to keep dreaming about her next designs.

“I’ve had people put letters under my door telling me that they took their baby’s first Halloween photo on my stoop and now that baby is 4,” she said, adding that she’s already designing her next stoop display, Candyland with a Twist, which will debut before Christmas.

“People have even gotten engaged here — right on my stoop. Doing this is so much fun.”