Titan arum to bloom – outside

Carolus stands three feet tall in Minns Garden on July 24
Carolus stands three feet tall in Minns Garden on July 24

‘Carolus’ – one of two flowering-sized Titan arums (Amorphophallus titanum) in the Liberty Hyde Bailey Conservatory’s collection – has broken dormancy and is preparing to bloom this summer.

But instead of unfurling its pungent inflorescence in the confines of the Conservatory, this year’s flowering will take place outside in Minns Garden, between the Plant Science Building and Tower Road.

“As far as we are aware, this is the first time anyone has tried this outside in a temperate region,” says Kevin Nixon, professor in the Plant Biology Section of the School of Integrative Plant Science and the Conservatory’s curator.  Titan arums produce the largest unbranched inflorescences in the plant world.

Paul Cooper, the Cornell University Agricultural Experiment Station greenhouse grower who maintains the Conservatory’s collection, planted Carolus’s massive 100-pound corm – an underground structure similar to a flower bulb – on June 14 in a pot in Minns Garden.  As of July 25, Carolus stood 38.5 inches and was growing about three inches per day.  (See Carolus’s growth chart to follow the plant’s progress.)

When it last bloomed in 2015, Carolus topped out at 76 inches tall. But predicting exactly when the inflorescence will peak this time around will be especially difficult, as the cooler temperatures outside could slow its progress. Best estimate right now is early to mid-August.

And the plan is not without some risk due to the possibility of severe weather or the plant not acclimating well to outdoor conditions in Ithaca and failing to fully develop. “Whatever happens, we’ll learn something new this year,” says Karl Niklas, Liberty Hyde Bailey professor in the Plant Biology Section of the School of Integrative Plant Science.

Read more and follow Carolus’s progress at the Liberty Hyde Bailey Conservatory website.