A sod story

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August 31, 2009 // UPDATED 8:18 am - August 31, 2009
By: Amanda Kushner
Amanda Kushner

// Target Field comes to life with 2.5 acres of new grass //

Finally Downtown has some green space.

Tucked away in a neighborhood defined by asphalt, concrete and old brick buildings, the Target Field has a new bed of grass — 2.5 acres of sod grown in Colorado.

In recent decades, the Twins have only played ball on a grass field while at away games. The first time Minnesotan Joe Mauer even saw a professional game played outside was when he became a professional player, said Twins spokesman Kevin Smith. But that is beginning to change, and a major milestone was completed by the end of August.

Truckloads of sod rolled into Downtown Minneapolis for a weeklong dash, which included transporting the sod from Fort Morgan, Colo., and an installation process that went through most of the nights.

“Baseball is meant to be played outside on natural grass,” Smith said. “ … This literally brings the field to life with this grass installation.”

Racing the clock

The plans have been in motion for years, and the final week of August was picked two years ago for the installation, said Dan Mehls, construction executive for Mortenson Construction.

Then one year ago a four-way blend of Kentucky bluegrass seeds was planted at Graff’s Turf Farms, said Marti Vocke, marketing director at the farm. Kentucky bluegrass was selected because of its deep, dark color, high-wear tolerance and its ability to repair itself well, said James Graff, co-owner of Graff’s Turf Farms.

Right on schedule at 4 a.m. on Aug. 24, following four hours of early morning harvesting, four refrigerated trucks departed from Fort Morgan with rolls of sod, each 300 square feet. It took about an hour to cut each truck load, which included 19 rolls, just shy of 6,000 square feet, Graff said.

The drivers then fit the 2,500-pound rolls into each truck, which were maintained at 40 degrees, Vocke said.

Once the sod was rolled, everyone raced the clock to get the sod down as quickly as possible. So what should be a two-day drive became a 24-hour hustle.

“Sod is a perishable product, so once it is harvested it is like a banana,” said Vocke, describing the transportation process. The sod had to be put down in
24 hours because if it does take too long “the banana is mushy and no good anymore,” she said.

Graff said the entire field was laid with sod from third base to the foul pole, the way head groundskeeper Larry DiVito requested.

And even before the sod was completely installed, Dave Mansell, senior superintendent with Mortenson said he expected the grass to take root in three days.

Location, location, location

Graff’s Turf Farms was chosen for two specific reasons: The company has the experience and the right location.

“In Colorado it is an old river basin … the grass is growing on 85 percent to 90 percent sand,” said Dan Kenney, executive director of the Minnesota Ballpark Authority. “And it’s a very specialized kind of turf that drains very, very quickly.”

The long list of sod grown for stadiums at the same location includes the Notre Dame stadium, the St. Louis Cardinals' Busch Stadium, the Chicago Cubs' Wrigley Field and the Colorado Rockies’ Coors Field, Kenney said.

“They have a tremendous amount of experience doing major league facilities, and it’s the right mixture for what we needed to have proper drainage,” Kenney said. “… It is really about the engineering of the field, so it is playable as soon as the rain stops.”

Minnesota Ballpark Authority Chairman Steve Cramer said that this was the most cost-effective method to bring in the turf. He said the field and subsurface system cost about $3 million. The sod cost $112,000, Smith said.

Twelve Minnesota and Wisconsin turf farms did not meet the required specs, Smith said.

He also said the team owed it to the fans to get the best sod, so they did it right the first time.

“We needed to get the best we could get, and Graff’s Turf Farms has a proven pedigree of athletic sports turf,” he said.

Perfect timing

The installation process took four early mornings and late nights, but after the first day, not only did the crew finish early, but they finished just in time.

“We finished literally laying the last roll, pulled the machines to the warning track, and it downpoured,” Graff said. “That is a turf farm’s dream. Where you can finish like that and get that much rain.”

But the turf did exactly what it was constructed to do.

Below the sod is an irrigation system, drainage system and heating system.

Three feet of soil was removed from the ground, and subgrade was put down to build up the field. Drainage gravel — large rocks that allow water flow and contain perpetrated pipes — were put on the subgrade.

Then on top of the gravel is a close network of pipes that contain a fluid, with 40 percent propylene glycol, which is heated by steam to heat the field, Mehls said.

That was topped with 10 inches of sand, which includes an irrigation system, Mehls said. And then the sod is the final layer on the field.

And in an effort to be environmentally sustainable, filters will make sure water is clean before entering the storm water management system, and the team is exploring the concept of reuse of the water for irrigation purposes, Kenney said.

Inside out

Kenney called the installation a testament to the work that Mortenson did as the construction manager and that Populous (formerly HOK Sport) did as the lead architect.

“This whole project was built from the inside out because we had an active freeway on one side, the Hiawatha extension on one side and the active Burlington northern rail line on another side,” he said.

Plus Kenney is excited to have 2.5 acres of grass in Downtown Minneapolis.

“If you think about just mowing the lawn, and the public plaza will be open, and you can smell the fresh cut grass, I think people will really enjoy that, even on non-game days.”