Editor’s note: San Diego State aims to complete its new 35,000-capacity stadium in time for the football team’s season opener against Arizona — Sept. 3, 2022 — which is now 92 days away. The Union-Tribune is doing monthly updates tracking the stadium’s progress.
JR Wirthlin would have been well within his rights this week to shout “get off my lawn” when a visitor walked on a patch of grass at the San Pasqual Valley sod farm.
But Wirthlin excused the intrusion.
And why not?
The grass underfoot was Latitude 36 Bermudagrass, a variety known for its heartiness, among other qualities.
Latitude 36 is grown exclusively in San Diego County by American Sod Farms, which within the next two weeks will be harvesting the grass and trucking it down to Mission Valley for installation at Snapdragon Stadium.
“SDSU chose it for the recovery aspect of it,” said Mike Kerns, director of field and grounds for Snapdragon Stadium. “It’s one of the top grasses when it comes to that. It’s great recovery for football and soccer in our wear patterns. … It’s a premier grass.”
Snapdragon Stadium is most notable as the new home to SDSU football, but its use will go far beyond 6-7 college football games a year.
The Aztecs men’s and women’s soccer teams will play there on special occasions.
There’s also going to be rugby with the San Diego Legion, women’s professional soccer with the San Diego Wave and potentially men’s professional soccer.
Add in concerts and other special events and there’s potentially 100-some on-field events each year at Snapdragon.
A grass that recovers well from frequent use is a necessity.
“You can do things with Latitude that you just can’t do with other varieties, as far as maintenance, rebounding and verticutting and mowing heights,” Wirthlin said. “It just gives a professional stadium manager a lot of options that he never had.”
Latitude 36 works especially well in the local climate, doing well underneath our May Gray and June Gloom cloudiness. Also, it won’t go totally dormant during the winter months.
“It just kind of outperforms most of the older turf varieties,” Wirthlin said.
Also appealing is a more rich green color.
“A lot of times with these bermuda grasses, they don’t stripe or have that dark green color you would get with a bluegrass or rye grass or anything like that,” Kerns said. “This bermuda grass, in particular, will look great on TV.
“Just look at Petco Park, and it’s the same grass.”
Petco switched 3-4 years ago from Bandera Bermuda to Latitude 36. It was also laid in on the tee boxes and approaches last year at Torrey Pines before the 2021 US Open.
It all comes from American Sod Farms, a local family-owned business started in 1978 by Wirthlin’s father and now spanning three generations.
Wirthlin shared the most knowledge about grass the visitor had heard since Carl Spackler, an assistant groundskeeper of some renown, spoke years ago of a hybrid blend with “Bluegrass, Kentucky Bluegrass, Featherbed Bent and Northern California Sinsemilla.”
Seven varieties of grass are currently being grown across 230 acres at American Sod Farms. Latitude 36 was developed at Oklahoma State about a decade ago. Wirthlin began growing it within the past five years.
The Snapdragon Stadium section was adjacent to another patch of Latitude 36 being grown for Banc of California Stadium in Los Angeles, home of the MLS’ LAFC.
A few hundred yards to the southeast was acreage reserved for Petco Park, which replaces its grass annually.
American Sod has been growing the Snapdragon grass since last August (and will repeat the process as soon as this is harvested). It is what Wirthlin called a “sand grow,” with the same type of sand used at the sod farm as that being spread at Snapdragon.
“I’m trying to grow roots, not grass,” said Wirthlin, who cored out a sample with a knife to display the root base. “This is what they’re after, a nice, deep root base with matured roots. When I harvest, it’s all about the roots.
“Grass is kind of like a bonus. Do a good job on the roots and you’re going to have nice grass. ,
Preparations for the sod at Snapdragon Stadium have been ongoing for months.
Addressing drainage was the first order of business.
The new stadium is being constructed about 500 feet northwest of where the former stadium was located.
Snapdragon is on higher ground, the result being that the field is about 10 feet higher than the old field, which was only a couple of feet above the water table in Mission Valley.
A 10” sand base is on top of nearly a half foot of stone, with gravity-fed drainage below that.
In recent days and weeks, fans observing activities on SDSU’s Stadium Cam live stream have watched dump trucks bring in some 600 tons of sand.
It is to provide a 10″ thick base of root zone mixture (90 percent sand, 10 percent peat moss), Kerns said.
In another week, additional soil amendments of 3-4” will be tilled in before the final laser grading is done in preparation for the sod installation.
When it comes time to harvest the grass, a piece of equipment Wirthlin called a “Big Roll Machine” will be brought in to cut the sod.
The machine harvests a roll of grass 3 1/2 feet wide and up to 110 feet long. For this grow, Wirthlin will go with 70-80 feet in length because of the extra weight of the sand on the harvester.
The depth of the cut is between 1/2 and 3/4 inch.
The 2-3 days of harvesting will begin the night before the grass is installed at Snapdragon. It needs to be placed immediately after delivery to protect the roots from degrading.
The entire surface of the field, including the sidelines and end zones will require about 95,000 square feet of sod. That’s a little more than 2 1/4 acres (there’s 43,560 square feet in an acre).
Transporting the sod will require about 14 truckloads — about six trucks per acre — from the San Pasqual Valley site down the I-15 to Snapdragon Stadium.
A crew of approximately a dozen people will spend the better part of three days securing the sod.
A machine rolls it out, then crew members go to work with rakes pulling and pushing the pieces together, making sure seams are tight between pieces.
They start at the farthest point from the entrance/exit tunnel (the southwest corner) and work their way back.
After all the sod is laid in, crew members walk the entire field looking for imperfections that need repair.
Any replacement patches need to be about 10 times the size of the tear in order to ensure that the sod will take hold and flourish.
At that point, it’s all about care and maintenance. Watering. Fertilizing. Mowing (to about a 1/2 inch).
Kerns will have a full-time crew of 3-4 people to maintain the field and a similar number of part-time help when necessary, such as paint days or flipping the field from football to soccer.
Kerns, who earned a degree in 2009 from Rutgers in Turf and Turfgrass Management, traces his fondness for grass to his youth in Philadelphia. His twin brother is in the same field.
Kerns’ experience includes field supervision in golf courses and professional baseball and soccer, most recently in the Northwest as head groundskeeper at Tacoma’s Cheney Stadium.
By the time the grass arrives at Snapdragon, it will be about 2 1/2 months before the new stadium’s scheduled debut.
That’s a tight timeline for the grass to really take root. Kerns isnt stressing.
“In the grass-growing business, patience is a virtue,” he said. “I learned that a long time ago.”