Mitchell Park Domes Plants Get Their Start in New Greenhouses Next Door

Aug 15, 2014

For decades, visitors have strolled the Mitchell Park Domes tropical flora, desert landscape and the seasonal "special" exhibit. But there's more going on that the public doesn't see.

A series of greenhouses has been taking shape, just east of the beehive-shaped glass structures. The staff is now moving in and, so too, the mums and poinsettias.

The greenhouse compound is surrounded by an forbidding black fence. Someone like Amy Thurner has to swipe you in. The horticulture manager started tending plants as a teenager.

“My first job was working in a greenhouse; so that was my first love," Thurner says. "There’s something about taking a plant from a seedling all the way to a bloom specimen that a customer finds a lot of joy in planting in their garden; that’s what interested me."

For decades the plants that we’ve seen at the Domes were grown in and transported from a greenhouse in Wauwatosa. But that facility was one of the casualties of the reconstructed Zoo Interchange. The new greenhouses have been a work in progress for more than a year in and half.

In the storage prep building, a huge freight elevator carries loads of soil up to the main level. The crew here goes through lots and lots of soil.

Mary Braunreiter is in high ordering mode.
Credit S Bence

It’s Mary Braunreiter’s job to figure out what – and how many – will be planted in that soil We find her pouring over catalogs and computer lists at her desk. She’s in the middle of placing orders. She plans way ahead.

Braunreiter works with a broker to purchase starter plants – called plugs from greenhouses “all over the place,”as she puts it. Purchasing seeds, she says, is much simpler to manage.

“I can just order from the see companies myself, the annual things like Dusty Miller. But some other plants are more difficult, so we get them from plugs, or they just do better from plugs,” Braunreiter says.

Braunreiter came to the Domes by way of a 14-year stint at Boerner Botanical Gardens; as for her skills, she credits her mom who was a bang-up houseplant grower, “and then my mother-in-law was totally into outdoor gardening with perennials.”

After years of working with plants outside, Braunreiter is learning to grow them “under glass.”

We find Clay Gosse – the newest horticulturalist of the bunch- rummaging around a storage room, trying to find a “suit” to fit his tall frame. That is a protective suit – Goss is about to apply pesticides to a sea of mum plants.

Gosse, an Appleton, Wisconsin native, says he fell into horticulture. In college at the University of Minnesota, a friend suggested he check out a plant propagation course. Wham! Goes says he was hooked.

But, how did he land this job?

“I didn’t know anyone here. I had just graduated and I was working landscaping and my mom actually found the job online for me,” Gosse says.

Gosse is giddy with excitement. Since joining the team, he has spent most of his time programming the sophisticated system critical to the greenhouse operation. It orchestrates everything from watering, to fertilizing to when the mum plants require extended darkness.

Chris Gaas, Amy Thurner and Clay Gosse
Credit S Bence

Today Gosse will step into the greenhouse.

“It’s my first time that I spray pesticides, but I’ll be working with a guy who has been doing it for 30 years,” Gosse says.

That’s horticulturalist Chris Gaar. With three decades under his belt, Garr is void of pretense, and simply calls himself…

“One of the horts. I help seed and grow. We start all of the stuff here,” Gaar says.

Manager Amy Thurner says Gaar is a master. She steers me toward the greenhouses to show me proof of it. Along the way, we run into one another team member – Marian French. She spends her time tending the arid dome plants. She says her tasks are like tending any other garden, “it’s just prickly.”

French is ferrying some “man-made” decorative barrel cacti toward her desert.

“They came from an artist, I think is, from Arizona, but I met him at the State Fair," French says. "There’s another one I just put in that’s a Saguaro cactus with the two arms and flowers; it’s gorgeous. It’ll be an inspiration for my baby Saguaros."

There’s an infectious “I love my job here” vibe in this place; but Thurner says they take their jobs very seriously.

Their core crops are poinsettias and the mums.

We pass through glass doors – mostly covered with cardboard – into the mum greenhouse. It’s a sea of a thousand regal plants – perfectly spaced so they don’t bump into one another as they grow.

“Our mums are always grown in two crops, because the flowering only lasts so long, and we have to replace them," Thurner says. "This is the first crop. We use the blackout cloth because they need an extended period of darkness to initiate flowering, so they’re ready for the show. Hence the cardboard on the doors because we’re trying to eliminate light from the hallway."

The plants look like they’re hooked up to life support systems. They each have individual watering and nutrition lines.

“They have irrigation tubes in them and it’s very nice they have enough room and don’t touch, because if they do touch then they’re not uniform anymore and they become distorted and don’t look professional and show-ready,” Thurner says.

Clay and Chris shuffle in – wearing their white protective suits.

“They’re going to be spraying these plants for aphids. This crop is very healthy and doing very well, but every plant has it’s pest. For mums it’s aphids, sometimes a spider mite. In the case of poinsettias, Chris [Gaar] will always be fighting white fly,” Thurner says.

As far as Thurner is concerned, it’s the Domes poinsettias – used in the winter show – that puts her team a notch above many other.

“These really make the Christmas show. This is what makes us very unique. It’s a floral poinsettia. It’s not like something you can buy at Home Depot or Lowe’s or anywhere. These are very unique," Thurner says.

The plants they’re nurturing now arrived just after the the 4th of July. Some are pinched back early to bush out. Others are raised to be straights. They grow to be up to three feet tall. Stems will be even thicker and the flowers will be just huge,” Thurner says.

She calls the results horticulturist Chris Gaar’s magic.

“He grows the most beautiful poinsettias I’ve ever seen. He’s got it down, so Clay is learning everything from him,” Thurner says.

She’s so busy with what’s above ground, I have to remind Thurner to tell me about the huge storage tanks built into the system to capture thousands of gallons of rainwater.

That too, is programmed into the greenhouse maintenance system.

“There are four 20,000 gallons tanks buried between Greenhouse 6 and Storage Prep, so we have the capacity of 80,000 gallons. That's one of the sources for all of the irrigation for the greenhouses,” Thurner says.

The rainwater captured in the tanks, comes off the greenhouse complex rooftops. And Thurner says, “is sanitized with a UV light system.”

Although they couldn’t be closer neighbors, Dome visitors won’t automatically be invited into its greenhouses. Thurner says the utmost care must be taken to keep their plants disease free.

But she admits, there’s more than one reason she’s delighted to live right next door to the Domes.

For years she helped grow plants at the Watertown Plank Road greenhouses; they’d be shipped over by truck and few people realized where the beautiful “creatures” came from.

“For me, that is really rewarding because people are starting to make the connection. You don’t just wave your wand and have all the beautiful flowers. We do that all ourselves here,” Thurner says.

Every once and a while visitors will see Thurner and her crew ferrying in new plants through the amply sized breezeway that connects her world to the Domes.

The greenhouse team also creates displays outside the Domes, for Boerner Botanical Gardens and other county parks.
Credit S Bence