Desert Plant Raising the Roof of its Chicago Home
For more than half a century, a plant at Chicago’s Garfield Park Conservatory has been growing slowly and imperceptibly.
Until last fall.
It’s called the century plant. A member of the agave family, the plant is more accustomed to the sunny deserts of Northern Mexico and the Southwestern U.S. than the overcast skies of a Chicago winter. But the plant is showing no signs of the winter blues. In fact, it’s exploding as if it were in its hot and arid natural habitat.
“It started growing a little bit in October,” said Ray Jorgensen, a Garfield Park Conservatory floriculturist. “But then in January, the tip of the inflorescence, or in Spanish, the ‘quiote’ [the plant’s central stalk], was like 7 feet, 2 inches. And by Feb. 1 it was 10 feet. So it grew by 3 feet in that month.”
The rapidly ascending century plant got its name from a once-held belief that it bloomed only once every 100 years. But in its natural habitat, the century plant usually blooms and dies off by age 30. The specimen at the Garfield Park Conservatory, however, defied the odds long ago.
“We don’t know exactly when it arrived,” Jorgensen said. “But from talking with past employees – some of which worked here for 40 years – it was here 50 years ago when they started.”
Toward the end of the plant’s life, its inflorescence shoots up to heights of 25 to 30 feet. It then sprouts panicles (branches) at the top that bloom. Over the past five months, the growth of this plant’s inflorescence has been dramatic.
“It’s not unusual for it to grow this quickly,” Jorgensen said. “In [its natural] habit it can often grow 6 inches a day. What is unusual is that it’s doing it in the middle of winter.”
Jorgensen has a hypothesis about why the century plant he tends is growing so quickly this winter. Jorgensen says he took a leave of absence last year and his colleagues were told to go easy on watering the plant. But when Jorgensen returned, he started giving the plant a lot of water again. It was after that period that the sudden and dramatic growth spurt started.
But now the keepers of the conservatory’s Desert House have a major concern: The century plant’s inflorescence is nearly 20 feet tall. The glass panes comprising the ceiling above the plant are only 25-feet high. If and when the stalk hits the ceiling, the staff is preparing to remove one of the hothouse glass panels to let the inflorescence through. That would be the first time in memory that’s been done. But if it happens while Chicago temperatures are still below freezing, it could damage the inflorescence and possibly prevent the plant’s flowering branches from emerging. So for the time being, the floriculturists have lowered the temperature in the cactus room to try to slow down the inflorescence’s growth until more springlike temperatures arrive.
Jorgensen is hoping for a warm-up very soon. “[The century plant] shows no sign of panicles yet which are at the top third,” he said. “So it’s probably got a bunch more growth in it and that could take weeks, possibly even a month, before the panicles show up.”
When the panicles sprout, the blossoms from the century plant will yield seeds and then the plant will gradually die over the course of several months. It’s succulent leaves at the base are already showing signs of its approaching demise: their tips have turned brown and frayed. But the century plant has already produced an offspring through it roots. The little pup, as its caretakers call it, sits next to its parent and is heir to the throne. But the reigning monarch will remain the star of the desert house as it continues climbing toward the sky.