It doesn't smell sweet, instead it smells like a dead body. The flower's name is Amorphophallus titanum, otherwise known as the corpse flower.
It only blooms once every 30 years or so, and can reach up to 12 feet in length.
For a couple of days, the corpse flower sends out a putrid stench to attract pollinators that eat dead animals. It can also generate heat.
This will be the first time a corpse flower will bloom at the Botanical Garden since 1937.
If you want to see it, but not smell it, a live stream of the blooming is available on the Botanical Garden's YouTube.