Through the years, we’ve trialed 27 different clones of Amorphophallus krausei in the garden for winter hardiness, but only two have consistently survived. The largest is a 2005 Alan Galloway collection from from Son La, Vietnam. Here it is in the garden this week with the 5′ tall flower spikes. The spikes are followed by 7′ tall leaf petioles, making this the tallest winter hardy amorphophallus we’ve encountered. We working to get this amazing giant propagated.
Back in the early 2000s, we grew the spiral ginger, Costus speciosus for many years, before finally loosing it in a very cold winter, but its potential hardiness has always fascinated us. In 2013, Georgia plantsman Ozzie Johnson collected a specimen near the border of North Vietnam and Southern China at 3,900′ elevation. Below is Ozzie’s collection this week at JLBG, after our recent winter of 11 degrees F. The same plant, growing in Atlanta, survived 5 degrees F this winter without protection, so I think we can safely say we have a Zone 7b hardy form. This exceptional clone has been named Costus speciosus ‘Wizard of Oz’. It will take a few years to build up stock, but we’ll get this one ready as fast as possible.