(Photo courtesy of Desert Botanical Garden)

Learning by doing in the outdoor classroom area.

(Photo courtesy of Desert Botanical Garden)

Some plants like it hot, some like a bit of chill.

(Photo courtesy of Desert Botanical Garden)

Boulders and reclaimed wood at the Hazel Hare Center for Plant Science.

Phoenix’s Desert Botanical Garden is known, obviously, for its plants. But it’s been undergoing a bit of a makeover in terms of its buildings. It’s part of the garden’s new horticultural center, and has been in the works for a few years; the first phase opened earlier this year. Kimberlie McCue, Director of Research, Conservation and Collections, says it was time for some updating — and upgrading.

"The impetus is evident in the old structures that we still have," McCue said. "They had been built over the course of about 30 years — really old, really tired, suboptimal, really, for providing the environmental conditions we needed to keep our world-class collection in world-class condition."

On a recent morning, McCue gave me a tour of what’s been built already — starting at the new greenhouse. Two cisterns outside can collect 2,800 gallons of water, and the roof allows for either full sun or shade inside.

"So, there are three bays to this greenhouse, and each bay is controlled separately, in terms of environmental conditions, and that allows us to give optimal conditions to the different kinds of plants that we have in our collection."

Each of the three bays is kept at different temperatures, and house different kinds of plants, ranging from those that prefer a little chill to those that like it hot. Those temperatures — and pretty much everything else inside the greenhouse — is controlled by computers. McCue opens the box, and shows me inside...

"All of the systems are programmed for keeping the environment within certain parameters, and so what you see in this cabinet, it’s all computerized, is controlling the shade panels above, the roof vents that open and close, the shade screens that are inside, the cooling water wall, the fans — everything is automatic. Our old systems, everything was done by hand, here we don’t have to worry about it. We set it and sort of forget it," McCue explained.

The old greenhouses were hoop houses which were lower and trapped heat, something not wanted in the desert, according to McCue.

"This greenhouse, our new greenhouse structure, has 18 feet of height, which of course, heat rises. That in itself allows it to get away from the plants," McCue said. "The roofs are peaked, and those peaked roofs can actually open, and so when it’s cooler at night, we can open those roof panels and vent the heat out."

The new greenhouses are also nicer to look at than the old ones, and that’s been a consideration in the new project. After we pass through a gate, McCue talks about trying to let visitors behind the curtain a bit.

"This is the public side, and so, there is a path that leads from the main trail that people can freely walk down this path and they can get down here to this gate that we just came through, and there is what we call the window in the wall. There’s no glass or anything here, but it’s an open space so people can look back into the back of house, they can see greenhouse west, they can see other plants that we have out in the open that we’re propagating…"

One goal for the garden was that visitors would be able to see what was happening behind the scenes.

"That was a big part of our design discussions, is that we wanted to be able to invite our guests more into how we operate and why we operate the garden from a horticultural perspective. And so, this was a very conscious decision that we made to make this a more accessible area," McCue said.

And that also influenced the design. The wall separating the public and back of house parts of the garden is made up of giant boulders. The gate is made of wood taken from palettes donated to the garden. A short walk up that path is a new classroom, with dried desert plants in the double-paneled wall. But, McCue said the design was more function than form.

"We said at the beginning, function is paramount. Everything has to do what we need it to do. And, our architect, he absolutely took that to heart. But he, I have to say, is really brilliant in bringing ideas for that design element, for that little ‘wow factor,’ for making spaces beautiful as well as functional."

I asked McCue how this new horticultural center helps the Desert Botanical Garden do what they do.

"We’re all about research, conservation, exhibition and education of desert plants," she said. "Those are the pillars of our mission. And so, education, of course, we have to do that. We want to do that, it’s one of our passions. And, this new facility gives us greater capacity to do that."

Including in a new outdoor classroom. McCue said that’ll allow students to, for example, learn to prune trees by… pruning trees, rather than by watching a PowerPoint presentation on how to do it.

She said the overall project also aims for a high level of sustainability — going for certification through the Living Building Challenge, which calls itself the world’s most rigorous proven performance standard for buildings. That includes not getting certified until a year after they open and showing they’re actually doing what they should be doing.

"Really, in the end, it’s about doing good and doing what’s right. We’re an environmental organization. We were founded on the premise of conserving desert plants and their habitats. And, the better that we build in harmony with our environment, the better we’re serving our mission, ultimately," McCue said.

McCue said garden officials would like to finish the rest of the build-out all at once, but acknowledges that likely won’t happen. She said the next priority is the Desert Conservation Laboratory, and then a second new greenhouse, an exhibit building and a unified shade structure. She said it’s cost $3.5 million to build what’s gone up so far, and estimates it wouldd cost $8-9 million if the garden were to finish the whole project now.