Federal Way's rhododendron garden has noticed how NW summer is affecting certain rhodys

What does Washington state have in common with Nepal, West Virginia, the Jiangxi province in China, and the Indian state of Sikkim?

All these places have chosen rhododendrons as their region's symbol. It's the provincial flower of Jiangxi and the national flower of Nepal. And it's the state tree of Sikkim. In Washington, the Pacific Rhododendron, aka Coast Rhododendron or Rhododendron macrophyllum, has been the state flower since the late 1800s (officially, since the 1950s).

But here's the thing: All the above mentioned rhododendrons are actually very different plants.

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"Most people think of, 'My grandma had this in her driveway. It's big, it's pink and red,'" said Atsuko Gibson, nursery manager and assistant curator at Federal Way's Rhododendron Species Botanical Garden. "But rhododendrons are such a diverse group of plants. Some rhodys can be grown like ground cover ... and some rhodys can be grown like a tree ... and everything in between."

Listen to Seattle Now's full conversation with Atsuko Gibson here.

The garden in Federal Way has more than 700 species of Rhododendron, mostly from the wild. Its curator even takes part in plant-hunting exhibitions and often brings back new varieties.

Out of this immense rhododendron world, only the Pacific rhody is native to the Washington state region. It blooms around June, mostly in mountainous regions, like Mount Rainier, Gibson noted while chatting with Seattle Now.

Gibson calls the Rhododendron Species Botanical Garden "a zoo for plants," offering an opportunity to see the eclectic array of rhodys, including varieties that may be extinct in the wild.

Gibson has noticed that in recent years, local conditions for rhododendrons have been changing. She told Seattle Now the summers have gotten warmer, and drier, with heat waves lasting longer than she recalls in the past. There are certain species that the garden can no longer grow because of this.

"Our summers, especially in the last five or six years or so, have changed," Gibson said. "I've seen massive die offs, especially in nurseries. When they're in a container, soils get exposed to heat a lot more. So, in the nursery, I'm seeing massive die offs after a heat event. We didn't used to have above 90 degrees seven days in a row, now we do. So, we are reevaluating what we can grow successfully."

That evaluation is key to the botanical garden, which has a mission to preserve and spread rhododendrons across the U.S.

"One of our missions is to distribute these rare species," Gibson said. "We have an onsite nursery where we grow rhodys from seed and cuttings, and we ship those all over the country."