ST. LOUIS COUNTY, Mo. – Though outside temperatures are in the 20s, the Missouri Botanical Garden’s Climatron remains in the 80s during the day. That means plants can keep growing and growing year-round. 

More than 1,400 tropical species call the Climatron home, but some of those plants can outgrow their space.

“Seventy foot tall at the highest point. But most trees aren’t right at the highest point. A lot of them grow farther down the dome where it’s only thirty or forty or fifty feet tall,” said Deborah Lalumondier, a Senior horticulturist with the Botanical Garden.

The Climatron is closed this week so horticulturists can trim trees that have reached the edges of the geodesic dome.

“They’ll grow eight to ten feet a year and get up against the dome, literally in a year. They get cut back every year,” Lalumondier said.

Crews will trim back fifteen to twenty trees during the closure.

“Pruning is like a haircut. It doesn’t hurt them at all,” Lalumondier said.

Trimming allows more sunlight to reach ground-level plants and allows the trees to continue actively growing. The work is often down in January or early February because the ground crews are busy with outside jobs the rest of the year.

“Especially on a day when it’s 20 degrees outside,” she said. “I know the outdoor crew that’s in here doing the trimming today being in here.”

Garden visitors can get back to warming up in the Climatron when it reopens Saturday. In the meantime, you can step into the Sachs Museum to warm up. Right now, the Garden has snowdrops and witch hazel blooming.