There are a number of tree ferns in our garden, some of which were already here (mainly Cyathea species), but I've planted one of my favourites, Dicksonia antarctica. It was just a stump when I put it in a couple of weeks ago, but now it's sprouting these beautiful fronds.
Seriously, they are growing around 2 cm a day. Remarkable energy reserves. Just imagine the frenzied mitosis going on in there!